Answer:
1.Ca atom has greater radius than Ca+2
2.F- ion has larger radius than F
1. The Ca+2 ion has a smaller radius than the Ca atom. 2. The F- ion has a larger radius than the F atom. 3. The trend for ionic radius vs. atomic radius is that ions are generally smaller than their corresponding atoms.
Explanation:1. The Ca+2 ion has a smaller radius than the Ca atom. When an atom loses electrons to become a cation, it loses its outermost electrons, resulting in a decrease in the size of its electron cloud and thus a smaller radius.
2. The F- ion has a larger radius than the F atom. When an atom gains electrons to become an anion, it adds electrons to its outermost energy level, resulting in an increase in the size of its electron cloud and thus a larger radius.
3. The trend for ionic radius vs. atomic radius is that ions are generally smaller than their corresponding atoms. Cations are smaller than their parent atoms because they have lost electrons, which reduces the electron cloud and decreases the size. Anions are larger than their parent atoms because they have gained electrons, which increases the electron cloud and increases the size.
Which types of organisms are required to complete the nitrogen cycle
help meee pleaseeeee
Answer:
see explanation
Explanation:
Using the periodic table, look at the top of each column => These are group numbers ... Typically (for american tables) the numbers are divided into A-Groups and B-Groups... For this post, you need to focus on the A-Groups, or 'Main Group Elements'... Now, the numbers also represent the number of valence (outer shell) electrons in the elements listed below that number. For example, under Group IA, all elements ( H, Li, Na, K, Rb, Cs & F) all have one (1) outer shell electron. All elements under IIA have two outer shell electrons, IIIA, 3 outer shell electrons and so on. The exception is Helium (He) which has only 2 outer shell electrons and is typically listed under Group VIIIA.
So ...
X· => H, Li & Na
X: => He(noble gas exception), Be & Mg
·X: => B & Al
:X: => C & Si
X(5 dots) => N
X(6 dots) => O
X(7 dots) => F & I
X(8 dots) => Ne
HELP PLZ!!!
If you have 40 grams of potassium nitrate in 100 grams of water at 20 C:
How many grams of potassium nitrate will fall to the bottom of the container?
Answer:
Approx. 8 grams of KNO3 will not dissolve
Explanation:
According to the curve at 20 degrees C only 32 grams of KNO3 can dissolve in 100 grams of water meaning if you hvae 40 grams of KNO3 in water at 20 degrees C ; 40-32= 8
3500 J of energy are added to a 0.5 mol sample of iron at 293 K. What is the final temperature of the iron in kelvins? The molar heat of iron is 25.1 J/(mol•K).
Answer:
[tex]T_2=571.9K[/tex]
Explanation:
Hello,
In this case, we consider the following formula defining the energy and the temperature change for the sample of iron:
[tex]Q=n_{Fe}Cp_{Fe}(T_2-T_1)[/tex]
Now, solving the final temperature, considering a positive inlet heat, we have:
[tex]T_2=T_1+\frac{Q}{n_{Fe}Cp{Fe}} =293K+\frac{3500J}{0.5mol*25.1J/(mol*K)} \\T_2=571.9K[/tex]
Best regards.
Answer:
Explanation:
Step 1: Data given
Number of heat transfer = 3500 J
Number of moles of iron = 0.5 moles
Initial temperature = 293 K
The molar heat of iron is 25.1 J/(mol*K)
Step 2: Calculate ΔT
Q = n* C * ΔT
⇒with Q = the heat transfer = 3500 J of energy
⇒with n = the number of moles iron = 0.5 moles
⇒with C = the molar heat of iron = 25.1 J/mol*K
⇒ΔT = the change of temperature = T2 - T1 = T2 - 293 K
3500 J = 0.5 moles *25.1 J/mol * K * ΔT
ΔT = 278.9
Step 3: Calculate ΔT
ΔT = 278.9 = T2 - T1 = T2 - 293 K
T2 = 278.9 + 293 K
T2 = 551.9 K
At 7.0c the volume of a gas is 49 mL at the same pressure it’s volume is 74Ml at what temperature
Answer:
la neta no se me llevo los puntos
Explanation:
no se ingles
The temperature at which the volume of the gas increases from 49 mL to 74 mL, keeping the pressure constant, is approximately 149.43 0C, calculated using Charles's Law.
The question involves the application of Charles's Law, which relates the volume of a gas to its temperature when the pressure and the amount of gas are held constant. To find the temperature at which the volume of gas increases from 49 mL to 74 mL, you need to set up a ratio using Charles's Law, which is V1/T1 = V2/T2, where T is in Kelvin. Make sure to convert Celsius to Kelvin by adding 273.15.
First, we'll convert the initial temperature from Celsius to Kelvin: T1 = 7.0 + 273.15 = 280.15 K. Next, we'll use the volumes provided (V1 = 49 mL and V2 = 74 mL) to find the final temperature, T2.
By re-arranging Charles's Law, we get T2 = (V2 × T1) / V1. Plugging the values in, T2 = (74 mL × 280.15 K) / 49 mL = 422.58 K. To present this temperature in Celsius, subtract 273.15 from it: T2 = 422.58 K - 273.15 = 149.43 °C.
Therefore, the temperature at which the volume of gas is 74 mL is approximately 149.43 °C.
Propane (C3 H8 (g), Delta.Hf = –103.8 kJ/mol) reacts with oxygen to produce carbon dioxide (CO2 , Delta.Hf = –393.5 kJ/mol ) and water (H2 O, Delta.Hf = –241.82 kJ/mol) according to the equation below. Upper C subscript 3 upper H subscript 8 (g) plus 5 upper O subscript 2 (g) right arrow 3 upper C upper O subscript 2 (g) plus 4 upper H subscript 2 upper O (g). What is the enthalpy of combustion (per mole) of C3 H8 (g)? Use Delta H r x n equals the sum of delta H f of all the products minus the sum of delta H f of all the reactants.. –2,044.0 kJ/mol –531.5 kJ/mol 531.5 kJ/mol 2,044.0 kJ/mol
Answer: -2044.0 kJ/mol
Explanation:
Answer on Edg 2020
Answer:
-2044.0 kJ/molExplanation:
5. A 28.4 g sample of aluminum is heated to 39.4 °C, and placed in a calorimeter containing 50.0 g of water. The
temperature of water increases from 21.00 °C to 23.00 °C. What is the specific heat capacity, C, of aluminum?
Answer:
C Al = 0.8975 J/g.K
Explanation:
Q = mCΔT∴ m Al = 28.4 g
∴ T Al = 39.4°C = 312.4 K
∴ m H2O = 50.0 g
∴ T1 H2O = 21°C = 294 K
∴ T2 H2O = 23°C = 296 K
∴ C H2O = 4,18 J/g.K
⇒ C Al = ?
in a calorimeter:
∴ Al give heat: Q Al < 0
∴ H2O revceives heat: Q H2O > 0
⇒ - Q Al = Q H2O
⇒ - (28.4 g)*(C Al)*(296 K - 312.4 K) = (50.0 g)*(4.18 J/g.K)*(296 K - 294 K)
⇒ - (- 465.76 g.K)*(C Al) = 418 J
⇒ C Al = (418 J) / (465.76 g.K)
⇒ C Al = 0.8975 J/g.K = 897.5 J/Kg.K
The specific heat capacity of aluminum in this example is 0.394 J/g °C. This was determined by calculating the heat gained by water and considering that it equals the heat lost by the aluminum, and subsequently solving for the specific heat capacity of aluminum.
Explanation:To find the specific heat capacity (C) of aluminum, we must consider the amount of heat transferred from the aluminum to the water (expressed as q). The heat gained by water is calculated using the equation q = m * C * ΔT, where m is the mass, C is the specific heat, and ΔT is the change in temperature. According to the question, water's mass (m) is 50.0g, its specific heat (C) is 4.184 J/g °C, and the difference in its temperature (ΔT) is 2.00 °C. So, the heat gained by water is q = 50.0g * 4.184 J/g * °C * 2.00 °C = 418.4 J.
The heat lost by aluminum is equal to the heat gained by water. Therefore, using the equation q = m * C * ΔT and plug in the values of q (418.4 J), m (28.4 g), and ΔT (39.4 °C), to solve for C, the specific heat of aluminum, we can rearrange the formula to C = q / (m * ΔT) = 418.4 J / (28.4g * 39.4 °C) = 0.394 J/g °C.
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A food substance kept at 0°C becomes rotten (as determined by a good quantitative test) in 8.3 days. The same food rots in 10.6 hours at 30°C. Assuming the kinetics of the microorganisms enzymatic action is responsible for the rate of decay, what is the activation energy for the decomposition process? Hint: Rate varies INVERSELY with time; a faster rate produces a shorter decomposition time. 1.67.2 kJ/mol 2.2.34 kJ/mol 3.23.4 kJ/mol 4.0.45 kJ/mol
Answer:
1. 67.2 kJ/mol
Explanation:
Using the derived expression from Arrhenius Equation
[tex]In \ (\frac{k_2}{k_1}) = \frac{E_a}{R}(\frac{T_2-T_1}{T_2*T_1})[/tex]
Given that:
time [tex]t_1[/tex] = 8.3 days = (8.3 × 24 ) hours = 199.2 hours
time [tex]t_2[/tex] = 10.6 hours
Temperature [tex]T_1[/tex] = 0° C = (0+273 )K = 273 K
Temperature [tex]T_2[/tex] = 30° C = (30+ 273) = 303 K
Rate = 8.314 J / mol
Since [tex](\frac{k_2}{k_1}=\frac{t_2}{t_1})[/tex]
Then we can rewrite the above expression as:
[tex]In \ (\frac{t_2}{t_1}) = \frac{E_a}{R}(\frac{T_2-T_1}{T_2*T_1})[/tex]
[tex]In \ (\frac{199.2}{10.6}) = \frac{E_a}{8.314}(\frac{303-273}{273*303})[/tex]
[tex]2.934 = \frac{E_a}{8.314}(\frac{30}{82719})[/tex]
[tex]2.934 = \frac{30E_a}{687725.766}[/tex]
[tex]30E_a = 2.934 *687725.766[/tex]
[tex]E_a = \frac{2.934 *687725.766}{30}[/tex]
[tex]E_a =67255.58 \ J/mol[/tex]
[tex]E_a =67.2 \ kJ/mol[/tex]
In order for fission reactions to be successful, they must be self-perpetuating, meaning they must be able to keep themselves going.
What do you call the minimum amount of material that is needed for the reaction to keep going?
A) isotope
B) mass defect
C) critical mass
D) neutron
Answer:
Option C is correct.
The minimum amount of material that is needed for a fission reaction to keep going is called the critical mass.
Explanation:
Nuclear fission is the term used to describe the breakdown of the nucleus of a parent isotope into daughter nuclei.
Normally, the initial energy supplied for nuclear fission is the energy to initiate the first breakdown of the first set of radioactive isotopes that breakdown. Once that happens, the energy released from the first breakdown is enough to drive further breakdown of numerous isotopas in a manner that leads to more energy generation.
But, for this to be able to be sustained and not fizzle out, a particular amount of radioactive material to undergo nuclear fission must be present. This particular amount is termed 'critical mass'
Hope this Helps!!!
A characteristic feature of any form of chromatography is the ________.a. calculation of an Rf value for the molecules separated. b. use of an inert carrier gas. c. use of a mobile and a stationary phase. d. use of molecules that are soluble in water.
Answer : The correct option is, (c) use of a mobile and a stationary phase.
Explanation :
Chromatography : It is a separation process or technique of a mixture in which a mixture is distributed between the two phases at different rates, one of which is stationary phase and another is mobile phase.
Mobile phase : The mixture is dissolved in a solution is known as mobile phase.
Stationary phase : It is an adsorbent medium and It is a solid, liquid or gel that remains immovable when a liquid or a gas moves over the surface of adsorbent. It remains stationary.
Hence, a characteristic feature of any form of chromatography is the use of a mobile and a stationary phase.
Calculate the new molarity that results when 250.mL of water is added to each of the following solutions.
a) 125 mL of 0.251 M HCI
B) 445 mL of 0.499 M H2SO4
C) 5.25L of 0.101 M HCO3
Answer:
The answer to your question is 1) 0.037 M 2) 0.32 M 3) 0.096 M
Explanation:
a) 125 ml of 0.251 M HCl
-Calculate the moles of HCl
Molarity = moles/volume
-Solve for moles
moles = Molarity x volume
-Substitution
moles = 0.251 x 0.125
= 0.0314
-Calculate the new molarity
Molarity = 0.0314/ (0.125 + 0.250)
-Simplification
Molarity = 0.014/0.375
-Result
Molarity = 0.037 M
2.-
445 ml of 0.499 M of H₂SO₄
-Calculate the number of moles
moles = 0.499 x 0.445
moles = 0.222
-Calculate the new molarity
Molarity = 0.222/(0.445 + 0.25)
Molarity = 0.222/0.695
Molarity = 0.32
3)
5.25 l of HCO₃ 0.101 M
Calculate the number of moles
moles = 0.101 x 5.25
moles = 0.53
-Calculate the Molarity
Molarity = 0.53 / (0.25 + 5.25)
Molarity = 0.53 / 5.5
Molarity = 0.096
The new molarity of each question is: (a): 0.0835 M, (b): 0.3194 M, and (c) 0.0964 M.
The new molarities after adding 250 mL of water to each solution are: a) 0.0835 M for the first solution (HCI) b) 0.3194 M for the second solution (H2SO4) c) 0.0964 M for the third solution (HCO3).
To calculate the new molarity after dilution, we can use the dilution equation:
[tex]\[ C_1V_1 = C_2V_2 \][/tex]
where [tex]\( C_1 \)[/tex] is the initial concentration, [tex]\( V_1 \)[/tex] is the initial volume, [tex]\( C_2 \)[/tex] is the final concentration, and [tex]\( V_2 \)[/tex] is the final volume.
Let's solve for each case:
a) For the first solution:
- Initial concentration [tex](\( C_1 \))[/tex] = 0.251 M
- Initial volume [tex](\( V_1 \))[/tex] = 125 mL
- Final volume [tex](\( V_2 \))[/tex] = 125 mL + 250 mL = 375 mL
We need to find the final concentration [tex](\( C_2 \))[/tex]. Using the dilution equation:
[tex]\[ C_1V_1 = C_2V_2 \][/tex]
[tex]\[ 0.251 \text{ M} \times 125 \text{ mL} = C_2 \times 375 \text{ mL} \][/tex]
[tex]\[ C_2 = \frac{0.251 \text{ M} \times 125 \text{ mL}}{375 \text{ mL}} \][/tex]
[tex]\[ C_2 = \frac{31.375 \text{ mL} \cdot \text{M}}{375 \text{ mL}} \][/tex]
[tex]\[ C_2 = 0.0835 \text{ M} \][/tex]
So, the new molarity for solution A is 0.0835 M.
b) For the second solution:
- Initial concentration [tex](\( C_1 \))[/tex] = 0.499 M
- Initial volume [tex](\( V_1 \))[/tex] = 445 mL
- Final volume [tex](\( V_2 \))[/tex] = 445 mL + 250 mL = 695 mL
Using the dilution equation:
[tex]\[ C_1V_1 = C_2V_2 \][/tex]
[tex]\[ 0.499 \text{ M} \times 445 \text{ mL} = C_2 \times 695 \text{ mL} \][/tex]
[tex]\[ C_2 = \frac{0.499 \text{ M} \times 445 \text{ mL}}{695 \text{ mL}} \][/tex]
[tex]\[ C_2 = \frac{222.005 \text{ mL} \cdot \text{M}}{695 \text{ mL}} \][/tex]
[tex]\[ C_2 = 0.3194 \text{ M} \][/tex]
So, the new molarity for solution B is approximately 0.3194 M.
c) For the third solution:
- Initial concentration [tex](\( C_1 \))[/tex] = 0.101 M
- Initial volume [tex](\( V_1 \))[/tex] = 5.25 L = 5250 mL
- Final volume [tex](\( V_2 \))[/tex] = 5250 mL + 250 mL = 5500 mL
Using the dilution equation:
[tex]\[ C_1V_1 = C_2V_2 \][/tex]
[tex]\[ 0.101 \text{ M} \times 5250 \text{ mL} = C_2 \times 5500 \text{ mL} \][/tex]
[tex]\[ C_2 = \frac{0.101 \text{ M} \times 5250 \text{ mL}}{5500 \text{ mL}} \][/tex]
[tex]\[ C_2 = \frac{530.25 \text{ mL} \cdot \text{M}}{5500 \text{ mL}} \][/tex]
[tex]\[ C_2 = 0.0964 \text{ M} \][/tex]
So, the new molarity for solution C is approximately 0.0964 M.
Uranium-235 has a half-life of 710 million years. If it is determined that a certain amount of stored U-235 will be considered safe only when its radioactivity has dropped to 0.10 percent of the original level, approximately how much time must the U-235 be stored securely to be safe?
(A) 7.1 x 10^6 years
(B) 7.1 x 10^7 years
(C) 7.1 x 10^8 years
(D) 7.1 x 10^9 years
(E) 7.1 x 10^10 years
Answer:
7.1 × 10⁹ years (D)
Explanation:
half life of the Uranium-235 = 710 million years
to find the time it will take for the U-235 need to be stored securely to be safe
taken the full percent = 100
100 / 2ⁿ = 0.1 where n is number of half-life it has undergone
100 / 0.1 = 2ⁿ
1000 = 2ⁿ
take log of both side
log 1000 / log 2 = n
n = 9.967 number of half-lives
the number of years it will take = 710 million × 9.967 number of half-lives = 7075.7 × 10⁶ years approx 7.1 × 10⁹ years
The correct option is D. [tex]7.1 \times 10^9 years[/tex]
The calculation is as follows:[tex]100 \div 2^n = 0.1[/tex]
here n is number of half-lives it has undergone
[tex]100 \div 0.1 = 2^n\\\\1000 = 2^n[/tex]
Now
take log of both side
[tex]log 1000 \div log 2[/tex] = n
n = 9.967 number of half-lives
Now
the number of years it will take should be
[tex]= 710\ million \times 9.967 \\\\= 7075.7 \times 10^6 \\\\= 7.1 \times 10^9 years[/tex]
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The atomic mass of europium is 151.9 amu. There are two naturally occuring isotopes on europium, eu-151 with a mass of 151.0 amu and eu153 with a mass of 153.0. The percent natural abundance of the eu151 should be
Answer:
55%
Explanation:
Let A represent isotope eu-151
Let B represent isotope eu-153
Let A% represent Abundance of isotope A (eu-151)
Let B represent abundance of isotope B (eu-153)
The abundance of isotope A (eu-151) can be obtained as follow:
Step 1:
Data obtained from the question include:
Atomic mass of Europium = 151.9 amu
Mass of isotope A (eu-151) = 151.0 amu
Mass of isotope B (eu-153) = 153.0
amu
Abundance of isotope A (eu-151) = A%
Abundance of B (eu-153) = B% = 100 - A%
Step 2:
Determination of the abundance of Abundance of isotope A (eu-151). This is illustrated below:
Atomic mass = [(Mass of A x A%)/100] + [(Mass of B x B%)/100]
151.9 = [(151 x A%)/100] + [(153x B%)/100]
151.9 = [(151 x A%)/100] + [(153x (100-A%))/100]
151.9 = [151A%/100] + [15300 -
153A%/100]
151.9 = (151A% + 15300 - 153A%) /100
Cross multiply to express in linear form
151.9 x100 = 151A% + 15300 - 153A%
15190 = 151A% + 15300 - 153A%
Collect like terms
15190 - 15300= 151A% - 153A%
- 110 = - 2A%
Divide both side by - 2
A% = - 110 / - 2
A% = 55%
Therefore the abundance of eu-151 is 55%
Answer:
The natural abundance of eu-153 is 45.0 %
The natural abundance of eu-151 is 55.0 %
Explanation:
Step 1: Data given
The atomic mass of europium is 151.9 amu.
eu-151 hass with a mass of 151.0 amu
eu153 hass a mass of 153.0 amu
Step 2: Calculate the percent natural abundance
natural abundance eu-151 = X
natural abundance eu-153 = 1-X
151.9 = 151.0* X + 153.0 * (1-X)
151.9 = 151.0X + 153.0 -153.0 X
-1.1 = -2.0 X
X = 0.55 = 55 %
The natural abundance of eu-153 is 45.0 %
The natural abundance of eu-151 is 55.0 %
This cold river of air travels from west to east in the northern hemisphere. In winter, it dips south helping to bring cooler air to most parts of the United States. This is the _________ jet stream.
Answer:
Polar Jet stream
Explanation:
Polar Jet stream is also called the polar front jet or mid latitude jet steam, it is a very powerful belt of the upper level winds which sits above the polar front. It is the strongest wind in the tropopause, it's movement is towards the westerly direction of the mid latitude.
Determine if the following compounds are likely to have ionic or covalent bonds. a. Magnesium oxide (MgO) _______________ b. Strontium chloride (SrCl 2 ) _______________ c. Ozone (O 3 ) _______________ d. Methanol (CH 4 O) _______________ 2. Predict if a silver coin will conduct electricity
Answer:
The answer to your question is below
Explanation:
Ionic bond is a kind of bond in which a metal attaches to a nonmetal. Also we know that a molecule has ionic bonding if the electronegativity is higher than 1.7.
Kind of elements Difference of electronegativity Bond
a) MgO Metal - Nonmetal 3.44 - 1.31 = 2.13 Ionic
b) SrCl₂ Metal -Nonmetal 3.16 - 0.95 = 2.21 Ionic
c) O₃ Nonmetal- Nonmetal 3.44 - 3.44 = 0 Covalent
d) CH₄O Nonmetal-Nonmetal 3.44 - 2.55 = 0.89 Covalent
Carbon, Hydrogen and oxygen are nonmetals
2) Silver coins can conduct electricity.
Taking into account the definition of ionic and covalent bond and conductive materials :
a. Magnesium oxide (MgO) Ionicb. Strontium chloride (SrCl₂) Ionic c. Ozone (O₃) Covalentd. Methanol (CH₄O) Covalenta silver coin will conduct electricity.Ionic bondAn ionic bond is a type of chemical bond that occurs when one atom gives up an electron to the other, in order for both to achieve electronic stability.
This union normally occurs between metal and nonmetal elements with different electronegativity, which means that the elements have different capacity to attract electrons.
In other words, an ionic bond is produced between metallic and non-metallic atoms, where electrons are completely transferred from one atom to another. During this process, one atom loses electrons and another one gains them, forming ions. Usually, the metal gives up its electrons forming a cation to the nonmetal element, which forms an anion.
Covalent bondThe covalent bond is the chemical bond between atoms where electrons are shared, forming a molecule.
Covalent bonds are established between non-metallic elements, such as hydrogen H, oxygen O and chlorine Cl. These elements have many electrons in their outermost level (valence electrons) and have a tendency to gain electrons to acquire the stability of the electronic structure of noble gas. The shared electron pair is common to the two atoms and holds them together.
This caseIn this case, you know that:
Mg: Metallic elementO: Non-metallic elementSr: Metallic elementCl: Non-metallic elementC: Non-metallic elementH: Non-metallic elementThen, the compound:
a. Magnesium oxide (MgO) Ionic
b. Strontium chloride (SrCl₂) Ionic
c. Ozone (O₃) Covalent
d. Methanol (CH₄O) Covalent
Silver coinElectrical conductivity is the property of a material that allows an electrical current to travel through its atomic structure, with low resistance from this material.
Conductive materials are those that offer little resistance to the passage of electricity. Electrons can circulate freely through material because they are loosely bound to atoms and can therefore conduct electricity.
In other words, conductive materials allow the free flow of electrons between particles, facilitating the conduction of electricity across the entire surface.
Conductors, then, are those that have a large number of free electrons that move through the material, transmitting charge more easily from one object to another.
Metals have several million atoms, each with two or three electrons in its outer orbit (valence electrons). These valence electrons, in metals, are characterized by a tendency to release electrons to achieve a certain stability in terms of their configuration. In this way they conduct electricity.
Silver Ag is a metal. Then a silver coin will conduct electricity.
Learn more about:
Ionic bondbrainly.com/question/14614895?referrer=searchResults brainly.com/question/24755818?referrer=searchResults brainly.com/question/24776745?referrer=searchResultsCovalent bondhttps://brainly.com/question/15094073?referrer=searchResultshttps://brainly.com/question/7357068?referrer=searchResultsWhat does pH measure? number of hydrogen atoms in an acid number of hydroxide atoms in a base concentration of hydrogen ions in solution concentration of hydroxide ions in solution
Answer:
Concentration of hydrogen ions in solution
Brainliest would be appreciated
Final answer:
pH measures the concentration of hydrogen ions in a solution and indicates its acidity or basicity. The pH scale ranges from 0 to 14, with lower values being acidic and higher values alkaline. The pH value represents the negative logarithm of the hydrogen ion concentration.
Explanation:
pH measures the concentration of hydrogen ions (H+) in a solution. In pure water, a small percentage of water molecules dissociate into equal numbers of hydrogen ions (H+) and hydroxide ions (OH−), which is a source of hydrogen ions in solutions. The pH scale, which ranges from 0 to 14, determines a solution's acidity or basicity; a pH less than 7 indicates acidity, greater than 7 indicates alkalinity, and a pH of 7 is neutral. The pH value is a negative logarithm of the hydrogen ion concentration, meaning that each whole number on the pH scale represents a tenfold increase or decrease in hydrogen ion concentration.
The pH of a solution provides a quick way to determine its acidity or basicity. High concentrations of hydrogen ions yield a low pH, whereas low concentrations result in a high pH. The relative acidity or alkalinity of a solution can significantly impact various chemical and biological processes, making pH an essential parameter in science and various industries.
Why is melting an ice cube a reversible physical change?
Answer:
Because you can freeze the water you melted back into a ice cube.
Explanation:
Melting an ice cube is a reversible physical change because it involves a change in state (from solid to liquid) that can be reversed (from liquid back to solid). No new substances are formed in this process, hence, it's a physical change, not a chemical one. The substance, water, maintains its identity throughout the process.
Explanation:Melting an ice cube is a reversible physical change because the process can be reversed by freezing. When an ice cube melts, it changes its state from solid (ice) to liquid (water) due to an increase in temperature. This is a physical change, not a chemical change because no new substances are formed - water (H2O) remains water in both solid and liquid states.
When the temperature drops, the liquid water can freeze back to become ice - this is the reverse of the melting process. Hence, it's considered a reversible physical change since we can revert the material (water) back to its original state (ice) under standard conditions. The key here is that the basic identity of the substance (water, in this case) does not change throughout this process.
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Find the empirical formula of a compound found to contain 26.56% potassium, 35.41% chromium and the remainder oxygen.
Please help ASAP!!!
Answer: [tex]KCrO_4[/tex]
Explanation:
First, calculate how much percent of oxygen there is. We know that the whole compound cannot exceed 100%, so we take that, and substract it from 26.56% and 35.41%.
100.00
- 26.56
-------------------
73.44
- 35.41
---------------------
38.03
That is how much of oxygen we have.
Potassium: 26.56% or 26.56g
Chromium: 35.41% or 35.41g
Oxygen: 38.03% or 38.03g
To find the empirical formula, you simply find the amount of mol that each one has. You can do this by using the atomic mass of each element.
[tex]Potassium: 26.56g(\frac{1mol}{39.10g})= 0.67mol[/tex]
[tex]Chromium: 35.41g(\frac{1mol}{52g})=0.68mol[/tex]
[tex]Oxygen: 38.03g(\frac{1mol}{16g})=2.38mol[/tex]
We now determine the lowest number and divide each mol by it. In this case, the lowest number is 0.67
[tex]Potassium: \frac{0.67mol}{0.67}=1[/tex]
[tex]Chromium:\frac{0.68mol}{0.67}=1[/tex]
[tex]Oxygen:\frac{2.38mol}{0.67}=3.55 = 4[/tex]
Finally, we take each element add add their respective number.
So, this empirical formula would be:
[tex]KCrO_4[/tex]
The empirical formula of a compound with 26.56% potassium, 35.41% chromium, and the rest being oxygen would be [tex]K_2Cr_2O_7[/tex]
The number of mole of each element in the compound can be found by dividing each element's percentage with their respective molar weights:
Potassium K = 26.56%
= 26.56/39.1
= 0.68
Chromium, Cr = 35.41%
= 35.41/52
= 0.68
Oxygen, O = 100 - 26.56+35.41
= 38.03/16
= 2.38
Divide each number of moles by the smallest.
K = 0.68/0.68
= 1
Cr = 0.68/0.68
= 1
O = 2.38/0.68
= 3.5
Thus, the empirical formula would be [tex]KCrO_{3.5}[/tex]
Multiply all by 2 to remove the fraction:
[tex]K_2Cr_2O_7[/tex]
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the pressure exerted by water at the bottom of a well is 0.50 atm. how many mmHg is this?
Answer:
0.5 atm is equal to 380mmHg.
Explanation:
For every 1 atm, it is equal to 760mmHg.
Therefore, 0.5 atm is 760/2, which is 380mmHg.
If a very complex closed system has 200 J of energy in it, then the energy converts from 1 form to another to another to another. How much energy should the system still have at the end?
At the end the energy of the system is the same as 200 J.
Explanation:
It is a closed complex system and it has 200 J of energy.
Here the system is converting from one form to another form and then to another form.
As we know that there is a conservation of energy when one form is converted to another form without losing or gaining energy, whereas it may convert from one form to another form with the energy being conserved.
So after there is a conversion of one form to another form but there is no loss or gain of energy and same energy must be retained.
Joe is concerned about the carbon dioxide emissions from his daily commute and the impact that it is having on global warming In his daily drive to and from work Joe travels 60 miles and gets 20mpg. Joe would like to know how many grans if carbon dioxide is emitted from his driving each day.
Amount of CO₂ emission per day is 11,356.23 g.
Explanation:
Joe travelling distance per day = 60 miles
Carbon dioxide emission per day = 20 mpg
Now we have to find the amount of carbon dioxide emitted per day by dividing the distance by the emission per day given in gallons.
Amount of Carbon dioxide emission = [tex]$\frac{distance}{emission amount}[/tex]
Amount of CO₂ emission in gallons = [tex]$\frac{ 60 miles}{20 mpg}[/tex]
= 3 gallons
Now we have to convert the gallons to grams as,
1 gallon = 3,785.41 g
3 gallons = 3 × 3785.41 g = 11,356.23 g
So the emission of CO₂ per day is 11,356.23 g.
Which conditions contain molecules with the same average kinetic energy as the molecules in 10.0 grams of co2 at 10 c?
Answer:
40g of CO2 at 10C
Explanation:
Since average kinetic energy depends on absolute temperature (directly proportional to absolute temperature) and independent of amount and nature of gas. given that is have same temperature.
40g of CO2 at 10C
Any gas at 10 ℃ would have the same average kinetic energy as 10.0 grams of CO2 at the same temperature due to the principles of the kinetic molecular theory.
The conditions that contain molecules with the same average kinetic energy as the molecules in 10.0 grams of CO2 at 10 ℃ would be any other mass of gas at the same temperature, since the average kinetic energy of the molecules of a gas depends only on temperature according to the kinetic molecular theory. This is true regardless of the type of gas or its mass, as long as the gases are at the same temperature.
For example, if you have helium gas at 10 ℃, the average kinetic energy of its molecules would be the same as that of the CO2 molecules at 10 ℃. This is because the kinetic molecular theory posits that all gases at the same temperature have the same average kinetic energy.
A gas in an engine cylinder expands from a volume of 10.0 L to 15.0 L against an external pressure of 1 atm and the system absorbs 300 J of heat in the process. Determine the work done by the system and the change in the system's internal energy, both in joules. Use this conversion scale to calculate the work done in joules: 1 L * atm
Answer: The work done by the system is -506.5 Joules and change in the system's internal energy is -206.5 Joules
Explanation:
According to first law of thermodynamics:
[tex]\Delta E=q+w[/tex]
[tex]\Delta E[/tex]=Change in internal energy
q = heat absorbed or released
w = work done or by the system
w = work done by the system= [tex]-P\Delta V[/tex] {Work is done by the system as the final volume is greater than initial volume and is negative}
w =[tex]-1atm\times (15.0-10.0)L=-5.00Latm=-506.5Joules[/tex] {1Latm=101.3J}
q = +300J {Heat absorbed by the system is positive}
[tex]\Delta E=+300+(-506.5)=-206.5J[/tex]
Thus the work done by the system is -506.5 Joules and change in the system's internal energy is -206.5 Joules
The work done by the system during expansion is -506.625 joules, and the change in internal energy is 806.625 joules.
The work done by the system when a gas expands from a volume of 10.0 L to 15.0 L against an external pressure of 1 atm can be found using the formula work (W) = -pressure (P) × change in volume (ΔV). First, we need to convert the pressure to joules by using the conversion 1 L·atm = 101.325 J. The change in volume (ΔV) is 15.0 L - 10.0 L = 5.0 L. Thus, the work done by the system can be calculated as W = -(1 atm) × (5.0 L) × (101.325 J/L·atm) = -506.625 J.
The change in the internal energy (ΔU) of the system can be found using the first law of thermodynamics, which is ΔU = Q - W, where Q is the heat absorbed by the system. In this case, Q = +300 J and the work done by the system, W, is -506.625 J. Therefore, the change in internal energy is ΔU = 300 J - (-506.625 J) = 806.625 J.
Hydrogen peroxide decomposes spontaneously to yield water and oxygen gas according to the reaction equation 2h2o2(aq)⟶2h2o(l)+o2(g) the activation energy for this reaction is 75 kj·mol−1. the enzyme catalase, found in blood, lowers the activation energy to 8.0 kj·mol−1. at what temperature would the non-catalyzed reaction need to be run to have a rate equal to that of the enzyme-catalyzed reaction at 25 °c?
Answer:
the temperature of the non- catalyzed reaction is = 2793.75 K
Explanation:
The reaction of the spontaneous decomposition of hydrogen peroxide to give water and oxygen is given as:
[tex]2H_2O_{2(aq)} ----> 2H_{2(l)} + O_2_{(g)}[/tex]
The activation energy of non-catalyzed reaction [tex]E{a_1} = 75 kJ/mol[/tex]
The activation energy of metal catalyzed reaction [tex]E{a_2} = 8 kJ/mol[/tex]
The temperature of metal catalyzed reaction [tex]T_2 = 25^0C[/tex] = (25+273)K = 298 K
The rate constant of the non-catalyzed reaction can be expressed as:
[tex]k_1 = Ae^{{-Ea_1}/RT_1}[/tex] ----- equation (1)
The rate constant of the metal catalyzed reaction can be expressed as:
[tex]k_2 = Ae^{{-Ea_2}/RT_2}[/tex]
Then [tex]k_1 = k_2[/tex]
[tex]Ae^{{-Ea_1}/RT_1}=Ae^{{-Ea_2}/RT_2}[/tex]
[tex]e^{{-Ea_1}/RT_1}=e^{{-Ea_2}/RT_2}[/tex]
[tex]\frac{Ea_1}{RT_1}}=\frac{Ea_2}{RT_2}}[/tex]
[tex]T_1 = \frac{Ea_1*T_2}{Ea_2}[/tex]
[tex]T_1 = \frac{75*298}{8}[/tex]
[tex]\\T_1 = 2793.75 \ K\\[/tex]
Thus; the temperature of the non- catalyzed reaction is = 2793.75 K
describe how revolution and year are related.
Hydrogen sulfide gas reacts with oxygen gas to form sulfur dioxide and water. What volume of oxygen is needed to completely react with 2.8 Liters hydrogen sulfide?
Answer:
4.2 L O₂ is needed to completely react with 2.8 L hydrogen sulfied.
Explanation:
Without pressure and temperature we cannot calculate the this vale
We assume that the reaction take place under standard Temperature and Pressure(STP).
At STP, One mole ([tex]6.023\times 10^{23}[/tex] particles) of any gas occupied volume 22.4 L.
The balanced equation of this reaction is
[tex]2H_2S+3O_2\rightarrow 2SO_2+2H_2O[/tex]
Now we use molar ratio.
[tex]2.8L\ H_2S . \ \frac{1 mol\ H_2S}{22.4L \ H_2S}\ . \ \frac{3 mol\ O_2}{2 mol \ H_2S} \ . \ \frac{22.4L\ O_2}{1 mol\ O_2}[/tex]
=4.2 L O₂
4.2 L O₂ is needed to completely react with 2.8 L hydrogen sulfied.
Final answer:
To determine the volume of oxygen needed to react with 2.8 liters of hydrogen sulfide, the stoichiometric ratio from the chemical equation is used, revealing that 4.2 liters of oxygen is required for complete reaction.
Explanation:
Stoichiometry of Hydrogen Sulfide and Oxygen Reaction
The question involves the stoichiometric relationship between hydrogen sulfide and oxygen gases during a chemical reaction. The balanced chemical equation for the reaction between hydrogen sulfide (H₂S) and oxygen (O₂) to produce sulfur dioxide (SO₂) and water (H₂O) is:
2H₂S(g) + 3O₂(g) → 2SO₂(g) + 2H₂O(g)
To find the volume of oxygen needed to react with 2.8 liters of hydrogen sulfide, we use the stoichiometric coefficients from the balanced equation, which tell us that 2 volumes of H₂S react with 3 volumes of O₂.
This gives us a ratio of:
2H₂S : 3O₂
Using this ratio, we can find the volume of oxygen required by setting up the proportion:
(2.8 L H₂S) / (2L H₂S) = (x L O₂) / (3L O₂)
Solving for x, we get:
x = (2.8 L H₂S) × (3L O₂) / (2L H₂S)
x = 4.2 L O₂
Therefore, 4.2 liters of oxygen gas is needed to completely react with 2.8 liters of hydrogen sulfide gas.
Select the correct answer.
Which term describes the unstable arrangement of the reacting particles as the reaction takes place?
A.
reactants
B.
activation energy
C.
products
D.
energy of reaction
E.
activated complex
Answer:
E. activated complex
Explanation:
En un depósito hay 800 litros de agua. Por la parte superior un tubo vierte en el depósito 25 litros por minuto, y por la parte inferior por otro tubo salen 30 litros por minuto. ¿Cuántos litros de agua habrá en el depósito después de 15 minutos de funcionamiento?
Answer:
Ninguno estará en el agua después de 15 minutos.
Explanation:
Tomar 25 + 30 = 55 por minuto de agua que sale. Como ahora sabemos eso, tómese 55 minutos por 15 minutos. Debe obtener 825, por lo tanto, no quedará agua.
- Avíseme si esto es incorrecto o si desea una explicación más detallada. Espero que esto haya ayudado!
According to unitary method, there will be 825 liters of water and hence there will be no water left .
What is unitary method?Unitary method is a process by which we find the value of a single unit from the value of multiple units and the value of multiple units from the value of a single unit. It is a method that we use for most of the calculations in math.
Water coming out= 25+30=55 liters of water comes out in 1 minute, thus in 15 minutes 15×55=825 liters will come out and hence there will be no water left.
Thus, according to unitary method, there will be 825 liters of water and hence there will be no water left .
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There are 800 liters of water in a tank. A tube pours 25 liters per minute into the tank at the top, and 30 liters per minute comes out at the bottom through another tube. How many liters of water will be in the tank after 15 minutes of operation?
Dominic made the table below to organize his notes about mixtures.
Properties of Mixtures
has no set composition
must have more than one state of matter
must have more than one substance
What mistake did Dominic make?
The title should read "Properties of Solutions" because some mixtures do not have all of the properties listed,
There is a definite recipe to make each mixture, so the composition of a mixture is set.
Although it is possible to have more than one state, it is also possible to have only one state.
A single substance can be used to make a mixture if the substance is composed of more than one element.
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Answer:
Although it is possible to have more than one state, it is also possible to have only one state.
Explanation:
which gas laws apply to each of the steps of the 4 stroke engine?
Answer:
The ideal gas law ... A gas turbine, which uses continuous combustion, simply exhausts its ... This makes them ideal for use in vehicles, as they also start up more ... A four stroke engine delivers one power stroke for every two cycles of ... ignition, exhaust) however, these steps occur 3 times per one spin of. Internal combustion engine.
Explanation:
Ideal gas law is applicable to each of the steps of the 4 stroke engine.
What is an ideal gas law?
The ideal gas law is a equation which is applicable in a hypothetical state of an ideal gas.It is a combination of Boyle's law, Charle's law,Avogadro's law and Gay-Lussac's law . It is given as, PV=nRT where R= gas constant whose value is 8.314.The law has several limitations.
It was first stated by Benoît Paul Émile Clapeyron in 1834 as a combination of the empirical Boyle's law, Charles's law, Avogadro's law, and Gay-Lussac's law. The ideal gas law is often written in an empirical form.
The state of an amount of gas is determined by its pressure, volume, and temperature. The modern form of the equation relates these simply in two main forms. The temperature used in the equation of state is an absolute temperature: the appropriate SI unit is the kelvin.
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