Josh decided to mix some vinegar with baking soda. He knew that a reaction occurred because he made careful observations. He noted that the mixture started to foam up and bubble and was white in color. How did Josh know that a chemical reaction occured? He was sure a reaction occurred because of
A) the formation of a gas.
B) the color of the mixture.
C) the smell of the vinegar.
D) the volume of the mixture.
Answer: its A
Explanation: i did the test myself so i know its A
If the specific heat of water is 4.186 kJ/kg∙°C, how much heat is required to increase the temperature of 1.2 kg of water from 23 °C to 39 °C?
To calculate the energy required to raise the temperature of any given substance, here's what you require:
The mass of the material, m
(r)-2-butanol reacts with potassium dichromate (k2cro4) in aqueous sulfuric acid to give a (c4h8o). treatment of a with sodium borohydride in ethanol gives b, which as the same boiling point and refractive index as (r)-2-butanol. draw the structure of
b.
Final answer:
The structure of compound B is 2-methyl-2-butanol, which is formed by the reduction of the carbonyl group of (R)-2-butanol. This reduction reaction converts the aldehyde group into a secondary alcohol group.
Explanation:
The structure of compound B, which has the same boiling point and refractive index as (R)-2-butanol, can be drawn as 2-methyl-2-butanol. The reaction of (R)-2-butanol with sodium borohydride in ethanol leads to the reduction of the carbonyl group of (R)-2-butanol, resulting in the formation of 2-methyl-2-butanol (compound B). This reduction reaction converts the aldehyde group of (R)-2-butanol into a secondary alcohol group.
Which of these collectively come under van der Waals forces?
Answer:
London dispersion forces and dipole-dipole interactions
Explanation:
Hello,
There are two intermolecular forces that are collectively referred to as Van der Waals Forces: London dispersion forces and dipole-dipole interactions.
London dispersion forces are the weakest intermolecular forces. They are temporary attractive forces that turn out when the electrons in two adjacent atoms occupy positions that make the atoms form temporary dipoles.
On the other hand, dipole-dipole interactions turn out when two dipolar molecules interact with each other through the containing space. In such a way, the partially negative portion of one of the polar molecules is attracted to the partially positive portion of the second polar molecule.
Best regards.
This diagram would represent the enthalpy changes in which of the following?
boiling liquid
hot pack
cold pack
melting solid
Determine the rate of a reaction that follows the rate law rate = k a m b i where
Final answer:
The rate of a reaction is determined by the rate law, which includes the concentration of reactants, the rate constant k, and the reaction orders m and n. These factors must be determined experimentally.
Explanation:
The rate of a reaction can be determined by the rate law which, for a given reaction, may have the form rate = k [A]m [B]n, where [A] and [B] are the molar concentrations of the reactants, k is the rate constant, and m and n are the reaction orders. To determine the rate of a reaction, one needs to know the values of the rate constant k and the reaction orders m and n, which must be obtained experimentally.
The value of the rate constant k is characteristic of the reaction under specific conditions such as temperature and pressure, and though it is independent of the reactant concentrations, it does vary with temperature. The units for k depend on the reaction orders m and n and the desired units for the rate, which are typically moles per liter per second (mol/L/s). For instance, if the concentration units are mol³/L³, then the units for k should adjust accordingly to ensure the rate remains in terms of mol/L/s.
Your body's "thermostat" is called the _____. thyroid hypothalamus thalamus parathyroid
Your body's "thermostat" is called the hypothalamus!
How many total atoms are in 0.330 g of P2O5?
Which type of radiation from the Sun has the greatest potential to harm human skin?
Ultraviolet (UV) rays, is the right answer.
The sun emits rays in an extended spectrum of wavelengths, the maximum of which is not visible to human eyes. The shorter wavelength means that the radiation is more energetic and that it has the greater potential for harm. Therefore, the UV Rays that has a wavelength between 290 and 400 NM, have great potential for harm to humans. Sunburn, Suntan are some of the common impacts of over-exposure of humans to UV. Skin cancer is another disease caused by the UV Rays. Thus, the most harmful sun rays to the human being are the Ultraviolet Rays.
What mass of natural gas (ch4) must you burn to emit 269 kj of heat? ch4(g)+2o2(g)âco2(g)+2h2o(g)δhârxn=â802.3kj express the mass in grams to three significant figures?
The mass of natural gas (CH₄) you need to burn to emit 269 kJ of heat is 5.38 g, expressed to three significant figures.
The combustion of methane is an exothermic reaction, meaning that it releases heat. The heat of combustion of methane is -802.3 kJ/mol, which means that 802.3 kJ of heat are released when 1 mole of methane is burned.
We can use this information to calculate the mass of methane needed to release 269 kJ of heat.
Mass of CH₄ = Heat / Heat of combustion
= 269 kJ / (-802.3 kJ/mol)
= 0.334 mol
= 5.38 g
Therefore, you need to burn 5.38 grams of methane to emit 269 kJ of heat.
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The mass of natural gas (CH4) that must be burned to emit 269 kJ of heat is 5.42 grams.
Explanation:To calculate the mass of natural gas (CH4) that must be burned to emit 269 kJ of heat, we can use the enthalpy of combustion per mole of methane. According to the given balanced chemical equation, the enthalpy change of the combustion reaction is -802.3 kJ.
From a previous similar question, we know that when 2.50 g of methane burns, 125 kJ of heat is produced. So, we can set up a proportion to find the mass of CH4 that corresponds to 269 kJ of heat:
(2.50 g methane)/(125 kJ heat) = (x)/(269 kJ heat)
Solving for x, we find that x = 5.42 g. Therefore, the mass of natural gas that must be burned to emit 269 kJ of heat is 5.42 grams (to three significant figures).
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What is the expected oxidation state for the most common ion of element 2
The most common ion of helium (element 2), which rarely forms, has an expected oxidation state of 0 due to helium's full valence electron shell and its nature as a noble gas.
The expected oxidation state for the most common ion of element 2, which is helium (He), is 0. Because helium is a noble gas, it rarely forms ions and typically remains unreactive due to its full valence electron shell. Therefore, the oxidation number of any noble gas in its elemental state, including helium, is 0.
A student decomposed 3.67g of copper (ii) hydroxide into copper (ii) oxide. how many ml of 3m h2so4 is need to react with all the copper (ii) oxide?
Water molecules are listed from A to B to C in
Answer: Option (B) is the correct answer.
Explanation:
A state of matter where molecules are held together by strong intermolecular forces of attraction are known as solid substances. As a result, they are unable to move from their initial place but they can vibrate at their mean position.
Hence, in solid substances the molecules have low kinetic energy.
In liquids, the molecules are held by less strong intermolecular forces of attraction as compared to solids. Due to which they are able to slide past each other. Hence, they have medium kinetic energy.
In gases, the molecules are held by weak Vander waal forces. Hence, they have high kinetic energy due to which they move rapidly from one place to another leading to more number of collisions.
Thus, we can conclude that water molecules are listed from A to B to C in least to greatest motion.
How many moles of CuCl2 are there if you have 650 grams of it?
What is the maximum mass of ethanol that can be made from 15.5 kg of glucose?
List a few of the physical properties of graphite.
Calculate the vapor pressure at 50°c of a coolant solution that is 52.0:48.0 ethylene glycol-to-water by volume. at 50.0°c, the density of water is 0.9880 g/ml, and its vapor pressure is 92 torr. the vapor pressure of ethylene glycol is less than 1 torr at 50.0°c.
The combustion of 987.0 g of methane in the presence of excess oxygen produces 1.543 kg of carbon dioxide. What is the percent yield
You are performing a titration of a triprotic acid, when you spill water on your lab notebook. you can read that: pka 1 = 1.40, pka 3 = 9.80. you have determined experimentally that the ph at the first equivalence point is 3.35, and the ph at the second equivalence point is 7.55. what is pka 2 for this acid?
Which statement best describes evolution?
A. Species have changed over time
B. Traits acquired during a lifetime are Passed to offspring
C. Earths organisms have not changed overtime
D. All of earths organisms were formed at the same time
Three 5-l flasks, fixed with pressure gauges and small valves, each contains 4 g of gas at 273 k. flask a contains h2, flask b contains he, and flask c contains ch4. rank the flask contents in terms of
The ranking of the flask contents in terms of molar masses is Flask C (CH4), Flask A (H2), Flask B (He)
Explanation:The ranking of the flask contents in terms of
Flask C (CH4)Flask A (H2)Flask B (He)This ranking is based on the molar masses of the gases. The molar mass of CH4 is 16 g/mol, the molar mass of H2 is 2 g/mol, and the molar mass of He is 4 g/mol.
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A neutral atom of which of the four element has the smallest radius
Some common fossil fuels are gasonline,____, coal and natural gas
Which electron configuration represents the element carbon (atomic number 6)? A)1s2 2s2 2p6 B)1s2 2s2 2p4 C)1s2 2s2 2p2 D)1s2 2s2
Final answer:
The electron configuration that represents carbon (atomic number 6) is 1s²2s²2p², reflecting two unpaired electrons in the 2p orbitals according to Hund's rule. So the correct option is C.
Explanation:
The correct electron configuration that represents the element carbon (atomic number 6) is C) 1s²2s²2p². Carbon has six electrons, and the way these electrons are distributed in the atom's orbitals determines the electron configuration. The first two electrons fill the 1s orbital, the next two fill the 2s orbital, and the remaining two occupy the 2p orbitals. According to Hund's rule, these two 2p electrons are unpaired in two different, but degenerate, p orbitals, maximizing the number of unpaired electrons and adhering to the Pauli exclusion principle. Thus, the electron configuration for carbon with its valence shell is represented as ns²np², where n represents the principal quantum number relevant to the orbital.
How many moles in 1.3g sodium bicarbonate
A sample of an ideal gas has a volume of 2.31 l at 287 k and 1.10 atm. calculate the pressure when the volume is 1.45 l and the temperature is 298 k.
Final answer:
To calculate the new pressure of an ideal gas when the volume decreases to 1.45 L and the temperature increases to 298 K, the combined gas law is used. The final pressure is found to be approximately 1.803 atm after substituting the given initial conditions and solving for the final pressure.
Explanation:
The question relates to the behavior of an ideal gas when it undergoes changes in volume, pressure, and temperature. To solve for the new pressure when the volume and temperature of a gas sample change, we use the combined gas law, which states that the ratio of the product of pressure and volume to the temperature is constant for a fixed amount of gas (P₁ * V₁) / T₁ = (P₂ * V₂) / T₂).
Given:
P₁ = 1.10 atm
V₁ = 2.31 L
T₁ = 287 K
V₂ = 1.45 L
T₂ = 298 K
We need to find the final pressure P₂.
To find the final pressure P2, we rearrange the combined gas law equation:
P₂ = (P₁ * V₁ * T₂) / (V₂ * T₁)
Now we plug in the known values:
P₂ = (1.10 atm * 2.31 L * 298 K) / (1.45 L * 287 K)
P₂ = (750.38 atm*L*K) / (416.15 L*K)
P₂ = 1.803 atm (rounded to three significant figures)
The final pressure of the gas when the volume is 1.45 L and the temperature is 298 K is approximately 1.803 atm.
Calculate the ph of a buffer that is 0.225 m hc2h3o2 and 0.162 m kc2h3o2. the ka for hc2h3o2 is 1.8 Ã 10-5. 4.60 9.26 4.74 4.89 9.11
Answer:
The pH of the buffer solution is 4.60.
Explanation:
Concentration of acid = [tex][HC_2H_3O_2]=0.225 M[/tex]
Concentration of salt = [tex][KC_2H_3O_2]=0.162 M[/tex]
Dissociation constant = [tex] K_a=1.8 \times 10^{-5}[/tex]
The pH of the buffer can be determined by Henderson-Hasselbalch equation:
[tex]pH=pK_a+\log\frac{[salt]}{[acid]}[/tex]
[tex]pH=-\log[1.8 \times 10^{-5}]+\log\frac{0.162 M}{0.225 M}[/tex]
pH = 4.60
The pH of the buffer solution is 4.60.
4.602
Further explanationGiven:
A buffer system consisting of 0.225 M HC₂H₃O₂ and 0.162 M KC₂H₃O₂.
The Ka for HC₂H₃O₂ is 1.8 x 10⁻⁵.
Question:
Calculate the pH of this buffer.
The Process:
Let us first observe the ionization reaction of the KC₂H₃O₂ salt below.
[tex]\boxed{ \ KC_2H_3O_2 \rightleftharpoons K^+ + C_2H_3O_2^- \ }[/tex]
The KC₂H₃O₂ salt has valence = 1 according to the number of C₂H₃O₂⁻ ions as a weak part.HC₂H₃O₂ and C₂H₃O₂⁻ are conjugate acid-base pairsHC₂H₃O₂ and C₂H₃O₂⁻ form an acidic buffer system.To calculate the specific pH of a given buffer, we need using The Henderson-Hasselbalch equation for acidic buffers:
[tex]\boxed{ \ pH = pK_a + log\frac{[A^-]}{[HA]} \ }[/tex]
where,
Ka represents the dissociation constant for the weak acid; [A-] represent the concentration of the conjugate base (i.e. salt); [HA] is the concentration of the weak acid.[tex]\boxed{ \ pH = pK_a + log\frac{[C_2H_3O_2^-]}{[HC_2H_3O_2]} \ }[/tex]
[tex]\boxed{ \ pH = -log(1.8 \times 10^{-5}) + log\frac{[0.162]}{[0.225]} \ }[/tex]
[tex]\boxed{ \ pH = 5-log \ 1.8 - 0.1427 \ }[/tex]
[tex]\boxed{ \ pH = 5 - 0.2553 - 0.1427 \ }[/tex]
[tex]\boxed{ \ pH = 4.602 \ }[/tex]
Thus, the pH of this buffer equal to 4.602.
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the mass number of a chronium atom is 52 and it has 24 protons. how many neutrons does this atom have?
Draw the diazonium cation formed when cytosine reacts with nano2 in the presence of hcl.
The diazonium cation formed when cytosine reacts with Nano2 in the presence of HCl is CH+N2+ C-.
Explanation:The diazonium cation formed when cytosine reacts with Nano2 in the presence of HCl can be represented as:
CH+N2+C-
In this structure, the cytosine molecule donates its amino group (NH2) to the diazonium cation (N2+) while losing a hydrogen ion (H+). The presence of HCl helps in the formation of the diazonium cation.