Answer
is: pH = 8,046.
c(H₃O⁺) = 4·10⁻⁹ M
= 4·10⁻⁹ mol/L = 0,000000004 mol/L.
pH = -logc(H₃O⁺).
pH = -log(4·10⁻⁹ mol/L).
pH = -(-8,046) = 8,046.
When pH is less than seven (pH<7),
solution is acidic.
When is equal seven (pH = 7), solution is
neutral.
When pH is greater than seven (pH >
7), solution is basic (like this example).
The pH of a 0.1 M solution of baking soda is calculated using the formula pH = -log[H+] and is approximately 8.4, indicating a slightly basic solution. Baking soda is a weak base and reacts with acids to produce CO₂, making baked goods light and fluffy.
To calculate the pH of a 0.1 M solution of baking soda (NaHCO₃), you need to use the formula for pH calculation:
pH = -log[H⁺]
Given that the [H+] (or [H₃O⁺]) concentration is 4.0 X 10⁻⁹, the calculation would be as follows:
pH = -log(4.0 X 10⁻⁹)
pH ≈ 8.4
This indicates that the solution is slightly basic, which aligns with baking soda's properties as a weak base.
Which material needs extra energy to enable the movement of free electrons? A. Conductor B. Semiconductor C. Insulator D. Element
is butter melting onto toast a chemical or a physical
Answer: "physical change" .
________________________________________________________
This would be a "physical change" . ________________________________________________________
Note: This would change from a "solid" to a "liquid" / mere rearrangement of molecules/ NOT a new chemical substance—hence, a "physical change".
________________________________________________________
What is the mass, in grams, of 7.20×1020 molecules of caffeine, c8h10n4o2?
Answer: 0.23 grams
Explanation:
According to avogadro's law, 1 mole of every substance weighs equal to its molecular mass and contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.
To calculate the number of moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given molecules}}{\text{Avogadro's number}}=\frac{7.20\times 10^{20}}{6.023\times 10^{23}}=1.2\times 10^{-3}moles[/tex]
1 mole of caffeine [tex](C_8H_{10}N_4O_2)[/tex] weighs = 194 g
[tex]1.2\times 10^{-3}[/tex] moles of [tex](C_8H_{10}N_4O_2)[/tex] weigh = [tex]\frac{194}{1}\times 1.2\times 10^{-3}=0.23g[/tex]
Thus mass of caffeine [tex](C_8H_{10}N_4O_2)[/tex] is 0.23 grams.
What type of stress is caused by two plates sliding past one another?
How do most vertebrates reproduce—sexually or asexually? What are gametes? How is an embryo produced?
I NEED THE ANSWER QUICK
What is the length of the hypotenuse of the right triangle ABC in the figure?
A. 6.2
B. 11.0
C. 5.8
D. 7.2
Sheena wants to list the outer planets from smallest to largest. Which is correct? Jupiter, Saturn, Uranus, Neptune Neptune, Jupiter, Uranus, Saturn Neptune, Uranus, Saturn, Jupiter Saturn, Uranus, Neptune, Jupiter
Writing net ionic equation:
A solution of diamminesilver(I) chloride is treated with dilute nitric acid.
So what I did was..
[Ag(NH3)2]Cl(aq) + HNO3(aq) -> __________
The answer is
[Ag(NH3)2]+ + Cl- + 2H+ -> AgCl + 2NH4+
I would guess that the oxidation #s for diamminesilver(I) chloride would be:
Ag +1
NH3 0
Cl -1
Can someone please show me the steps in between?
I don't really know how to break the [Ag(NH3)2]Cl apart and predict/form the products.
In this net ionic equation, we can see that the silver ion ([Ag(NH3)2]+) reacts with the chloride ion (Cl-) to form silver chloride (AgCl). Additionally, the two hydrogen ions (2H+) react with the two ammonia molecules (2NH3) to form two ammonium ions (2NH4+).
To write the net ionic equation for the reaction between diamminesilver(I) chloride and dilute nitric acid, let's break down the steps:
1. Start with the balanced molecular equation: [Ag(NH3)2]Cl(aq) + HNO3(aq) ->
2. Identify the ions present in the reactants and determine if any of them are spectator ions. In this case, we have [Ag(NH3)2]Cl and HNO3.
The [Ag(NH3)2]Cl dissociates into two ions: [Ag(NH3)2]+ and Cl-. However, HNO3 is a strong acid and fully dissociates into H+ and NO3- ions.
Therefore, the spectator ions in this reaction are Cl- and NO3-.
3. Write the net ionic equation by removing the spectator ions:
[Ag(NH3)2]+ + 2H+ -> AgCl + 2NH4+
In this net ionic equation, we can see that the silver ion ([Ag(NH3)2]+) reacts with the chloride ion (Cl-) to form silver chloride (AgCl). Additionally, the two hydrogen ions (2H+) react with the two ammonia molecules (2NH3) to form two ammonium ions (2NH4+).
To determine the oxidation numbers, you are correct in assigning +1 to silver (Ag) and -1 to chloride (Cl). However, the oxidation number of ammonia (NH3) is 0 because hydrogen (H) has an oxidation number of +1 and there are no other elements to balance out the charge.
To know more about net ionic equation:
https://brainly.com/question/29299745
#SPJ6
Write the dissociation reaction and the corresponding ka equilibrium expression for hcn in water
The dissociation reaction of HCN in water is HCN(aq) ↔ H⁺(aq) + CN⁻(aq).
Here is the balanced dissociation reaction for hydrocyanic acid (HCN) in water:
HCN(aq) ↔ H⁺(aq) + CN⁻(aq)
The equilibrium expression for the acid dissociation constant (Ka) for this reaction is given by:
Ka = [H⁺][CN⁻] / [HCN]
This expression shows that the equilibrium constant (Ka) for HCN dissociation is determined by the concentrations of the hydrogen ions (H⁺), the cyanide ions (CN⁻), and the undissociated hydrocyanic acid (HCN) in the solution.
what is the urinary system and what does it do
Write the net ionic equation for the precipitation of cobalt(ii) carbonate from aqueous solution
If the molecular mass of tetraoxosulphate(VI) acid is 98, calculate it's vapour density.
Which of the following statements is true? Oceanic crust is thicker than continental crust. Both oceanic and continental crust is made of granite. According to continental drift, the continents were once connected. The crust is thickest layer of the Earth.
Answer: According to continental drift, the continents were once connected
Explanation:
According to continental drift, the continents were once connected this statement is true.
What is true about continental drift ?Pangaea split into fragments over the course of millions of years, and each piece migrated away from the other. These components gradually came together to form the continent that is known today.
Today's scientists believe that a number of supercontinents, including Pangaea, have developed and fragmented during the Earth's history.
The theory of continental drift holds that Earth's continents have shifted relative to one another during geologic time, giving the impression that they have "drifted" over the ocean floor.
During one or more geologic periods, continents moved horizontally at a huge scale in relation to one another and to the ocean basins. This idea served as a crucial building block for the theory of plate tectonics, which includes it.
Thus, option C is correct.
To learn more about continental drift follow the link;
https://brainly.com/question/28168801
#SPJ3
Will a precipitate form when 65.0 mL of 0.0200 M Ag2SO4 is mixed with 50.0 mL of 0.00500 M K2CO3? (Ksp for silver carbonate is 8.00 x 10–12).
Yes, the precipitate of silver carbonate will form.
To determine if a precipitate will form when 65.0 mL of 0.0200 M Ag2SO4 is mixed with 50.0 mL of 0.00500 M K2CO3, we need to compare the ion product (Qsp) with the solubility product constant (Ksp) for silver carbonate (Ag2CO3).
First, let's calculate the concentrations of ions after mixing the solutions:
For Ag2SO4:
- Initial moles of Ag2SO4 = 0.0200 M * 0.0650 L = 0.00130 moles
- Moles of Ag+ ions = 2 * 0.00130 moles = 0.00260 moles
- Concentration of Ag+ ions = 0.00260 moles / (0.0650 L + 0.0500 L) = 0.0200 M
For K2CO3:
- Initial moles of K2CO3 = 0.00500 M * 0.0500 L = 0.000250 moles
- Moles of CO3^2- ions = 0.000250 moles
- Concentration of CO3^2- ions = 0.000250 moles / (0.0650 L + 0.0500 L) = 0.00192 M
Now, to find out if a precipitate will form, we calculate the ion product, Qsp, for silver carbonate:
Qsp = [tex][Ag+]^2 * [CO3^2-][/tex]
Qsp = [tex](0.0200)^2 * (0.00192)[/tex]
Qsp = 7.68 x 10^-6
Compare Qsp with the Ksp of silver carbonate (Ag2CO3):
Ksp = 8.00 x 10^-12
Since Qsp (7.68 x 10^-6) is greater than Ksp (8.00 x 10^-12), the ion product exceeds the solubility product constant. According to the principles of solubility and precipitation, when Qsp > Ksp, a precipitate of silver carbonate (Ag2CO3) will form.
The precipitate of silver carbonate (Ag2CO3) will form when 65.0 mL of 0.0200 M Ag2SO4 is mixed with 50.0 mL of 0.00500 M K2CO3.
Use ksp=4.87×10−17 to calculate the solubility of iron (ii) hydroxide in pure water in grams per 100.0 ml of solution. g
The solubility product constant is the equilibrium constant of a substance in an aqueous solution. The solubility of iron (ii) hydroxide is [tex]2.07 \times 10^{-5}\;\rm g.[/tex]
What is Ksp?Ksp is the solubility product constant, which is given as the product of the concentration of cation and anion dissociated in the aqueous solution.
Given,
Ksp = [tex]4.87 \times 10^{-17}[/tex]
Thus,
[tex]\begin{aligned}&= \rm [Fe^{2+}][OH^{-}]^{2} \\\\&= \rm (X)(2X)^{2} \\\\&= \rm 4X^{3}\end{aligned}[/tex]
The molarity can be calculated as:
[tex]\begin{aligned}\rm 4X^{3} =4.87 \times 10^{-17}\\\\\rm X= 2.30 \times 10^{-6}\;\rm M\end{aligned}[/tex]
The mass of iron (ii) hydroxide in 100 mL of water is calculated as:
[tex]\begin{aligned}2.30 \times 10^{-6} \;\rm mol/L &= 2.3 \times 10^{-5}\;\rm mole/100 mL\\\\&= 2.07 \times 10^{-5} \;\rm g\end{aligned}[/tex]
Therefore, the solubility of iron (ii) hydroxide is [tex]2.07 \times 10^{-5}\;\rm g.[/tex]
Learn more about solubility here:
https://brainly.com/question/9330439
How much heat is absorbed by 15.5 g of water when its temperature is increased from 20.0°C to 50.0°C? The specific heat of water is 4.184 J/(g°C).,
Answer : The heat absorbed by the water is 19.4 kJ
Explanation :
Formula used :
[tex]Q=m\times c\times \Delta T[/tex]
or,
[tex]Q=m\times c\times (T_2-T_1)[/tex]
where,
Q = heat absorbed = ?
m = mass of water = 15.5 g
c = specific heat of water = [tex]4.184J/g^oC[/tex]
[tex]T_1[/tex] = initial temperature = [tex]20.0^oC[/tex]
[tex]T_2[/tex] = final temperature = [tex]50.0^oC[/tex]
Now put all the given value in the above formula, we get:
[tex]Q=15.5g\times 4.184J/g^oC\times (50.0-20.0)^oC[/tex]
[tex]Q=1945.56J=1.94\times 10^3J=1.94kJ[/tex]
Therefore, the heat absorbed by the water is 19.4 kJ
Which particles in an atom could demonstrate that opposite charges attract?
A.
a neutron and an electron
B.
two protons together
C.
a proton and a neutron
D.
a proton and an electron
Which changes are evidence of a chemical reaction? a beaker of water becomes hot to the touch upon?
PLEASE!! *MEASURING MATTER VOCAB MATCHING*
words:
1. matter
2. accuracy
3. precision
4. meniscus
5. volume
6. density
definitions:
- the mass of an object per unit volume
- anything that has mass and occupies space
- space occupied, measured in cubic units
- the degree to which a measurement can be replicated
- the curved top surface of a liquid column
- an indication of how close a measurement is to the correct result
MATCH THE WORDS TO THE DEFINITIONS PLEASE & THANK YOU!!
The words 'matter', 'accuracy', 'precision', 'meniscus', 'volume', and 'density' have been linked with their suitable definitions, clarifying their individual meanings.
Explanation:Here are the words matched to their definitions:
Matter: Anything that has mass and occupies space.Accuracy: An indication of how close a measurement is to the correct result.Precision: The degree to which a measurement can be replicated.Meniscus: The curved top surface of a liquid column.Volume: Space occupied, measured in cubic units.Density: The mass of an object per unit volume.Learn more about Vocabulary Matching here:https://brainly.com/question/29261631
#SPJ2
How much energy is released if 3705g of octane are burned
Which of the following is a benefit of having a standard measurement system that can be used by scientists worldwide?
1. Scientists can all perform different experiments
2. Scientists can compare and share data with each other.
3. Scientists never have to report their results.
4. Scientists can save their data for future experiments.
I think the answer is answer #2. Is this correct?,
what are the five indicators of a chemical change
how much water vapor can a cubic meter of air hold at 25 degrees celcius
Which of these is an example of a physical change?
sugar, when heated, producing carbon dioxide and water
solid ice, when heated, turning into liquid water
sodium, when exposed to chlorine, forming sodium chloride
aluminum, when heated in air, forming aluminum oxide
Answer: Option (b) is the correct answer.
Explanation:
When there is no change in chemical composition of a substance then this change is known as physical change.
Where as when there is change in chemical composition of a substance then it is known as chemical change.
When sugar is heated, it results in the formation of carbon dioxide and water. This means that composition of sugar has changed thus, it is a chemical change.
When solid ice is melted, it turns into liquid. This shows that only state of water has changed. There is no change in chemical composition because when we freeze water then again liquid water changes into solid ice. Thus, it is a physical change.
When sodium reacts with chlorine then the reaction is as follows.
[tex]2Na + Cl_{2} \rightarrow 2NaCl[/tex]
It shows that chemical composition of sodium has changed due to the formation of sodium chloride. Thus, it is a chemical change.
Also, when aluminium is is heated in air then it results in the formation of aluminium oxide. This means that the chemical composition of aluminium has changed.
Hence, we can conclude that out of the given options, solid ice, when heated, turning into liquid water is an example of a physical change.
Please help!!!!! Why is a spectrum for a given element unique for that element? A. No element has more than two electrons in the first shell. B. Each element has a unique arrangement of electrons. C. Atoms of different elements have different masses. D. Atomic nuclei contain no electrons.
Each element has a unique arrangement of electrons, so each element has different spectrum. Therefore, the correct option is option B.
What is element?The quantity of protons an element has defines it. An element's atoms all contain the same amount of protons, but its electron and neutron counts might vary. Ions are produced by altering the electron to proton ratio, whereas isotopes are produced by altering the neutron count.
A material that cannot be destroyed chemically is referred to as a chemical element. Although chemical processes cannot modify an atom, nuclear reactions can create new elements. Each element has a unique arrangement of electrons, so each element has different spectrum.
Therefore, the correct option is option B.
To learn more about element, here:
https://brainly.com/question/29545466
#SPJ6
HELP ASAP!!!
Carbon dioxide (CO2) is a gaseous compound. Calculate the percent composition of this compound. Answer using three significant figures.
What is the percent by mass of carbon?
%
What is the percent by mass of oxygen?
%
MnO2+ 4HCL--->MnCl2+Cl2+2H2O:
if 0.86 mole of MnO2 and 48.2g of HCL react, which reagent will be used up first? How many grams of Cl2 will be produced?
The answers are HCL, and 23.4g.
How would I get these answers?,
When the concentration of solute in a solid solution exceeds its solubility limit, a new solid solution or phase forms that has a composition distinctly different than the original solid solution?
When solute concentration exceeds the solubility limit in a solution, a supersaturated solution is created, which subsequently initiates precipitation in order to achieve equilibrium. This results in the formation of a new solid phase that is distinct from the original solution.
Explanation:The concept you're referring to involves solubility and the formation of new phases when the concentration of a solute in a solution exceeds its solubility limit. Solubility refers to the maximum amount of solute that can be dissolved in a solvent at a given temperature. When this limit is surpassed, a supersaturated solution is formed. This is not a stable state, and it often results in precipitation. This is the process where a solute becomes insoluble and forms a new, separate solid phase.
For instance, if we take a saturated solution of silver chloride (AgCl), and add more AgCl to it, the excess will precipitate out of solution. Here, the concentration of AgCl has exceeded its solubility, leading to the formation of a new solid phase that is distinct from the original solution.
The exact composition and form of the new solid phase can depend on a variety of factors, including the type of solvent and solute involved, temperature, and pressure.
Learn more about Solubility and Precipitation here:https://brainly.com/question/35451188
Which of the following are changing when a change of state is occurring?
Select all that apply.
temperature change
amount of intermolecular bonds
vibration of particles
position of particles
A substance is 35.7% carbon by mass. how much carbon could be recovered from 769 g of the substance?
The amount of carbon that could be recovered from 769g of a substance that is 35.7% carbon by mass is approximately 275g.
Explanation:The question involves a percentage by mass calculation, which falls under the subject of Chemistry. The substance in question is 35.7% carbon by mass. Therefore, to find the amount of carbon in a 769g sample, we multiply the total mass of the substance by the percentage of carbon.
Here's the calculation: 769g (total mass) x 0.357 (percentage of carbon as a decimal) = 274.653g. Therefore, we can recover approximately 275g (if we round to the nearest whole number) of carbon from the 769 g of the substance.
https://brainly.com/question/28709310
#SPJ12
To find how much carbon is in 769 g of a substance that is 35.7% carbon by mass, multiply 769 g by 0.357. This calculation shows that 274.833 g of carbon can be recovered.
To determine this, we can use the percentage by mass to find the amount of carbon in the total mass of the substance. Here's the step-by-step calculation:
First, convert the percentage into a decimal: 35.7% = 0.357
Amount of carbon = mass of the substance × percentage of carbon (in decimal form)
Amount of carbon = 769g × 0.357
Amount of carbon = 274.553g
Therefore, you could recover approximately 274.553 grams of carbon from 769 grams of the substance.