Answer:
C
Explanation:
A negative deltaH means that the reaction has to give up heat in order to happen. You have to treat deltaH as a reactant. So the question is do you need to add heat to the reactants to make the products. If you do, deltaH is plus.
Heat is required to make a solid go to a gas. deltaH is plus. A is not the answer.
A lot of heat is required for B (something like 400 Kj / mole. Like A, deltaH is plus and B is not the answer.
C: The liquid has to give up heat in order for the this reaction to take place. C is the answer.
D requires heat. It is not the answer.
Answer:
- Last choice: <em><u>- 3.72°C</u></em>
Explanation:
The freezing point depression in a solvent is a colligative property: it depends on the number of solute particles.
The equation to predict the freezing point depression in a solvent is:
Where,
- ΔTf is the freezing point depression of the solvent,
- Kf is the cryoscopic molal constant of the solvent, and i is the Van'f Hoff factor, which is the number of ions produced by each unit formula of the ionic compound.
The calcualtions are in the attached pdf file. Please, open it by clicking on the image of the file.
Answer:
Explanation:
Since water has a chemical formula of H2O , there will be 2 moles of hydrogen in every mole of water. In one mole of water, there will exist approximately 6.02⋅1023 water molecules.
Answer:
[C₆H₅COO⁻][H₃O⁺]/[C₆H₅COOH] = Ka
Explanation:
The reaction of dissociation of the benzoic acid in water is given by the following equation:
C₆H₅-COOH + H₂O ⇄ C₆H₅-COO⁻ + H₃O⁺ (1)
The dissociation constant of an acid is the measure of the strength of an acid:
HA ⇄ A⁻ + H⁺ (2)
![K_{a} = \frac{[A^{-}][H^{+}]}{[HA]}](https://tex.z-dn.net/?f=%20K_%7Ba%7D%20%3D%20%5Cfrac%7B%5BA%5E%7B-%7D%5D%5BH%5E%7B%2B%7D%5D%7D%7B%5BHA%5D%7D%20)
(3)
<em>Where the dissociation constant of the acid (Ka) is equal to the ratio of the concentration of the dissociated forms of the acid, [A⁻][H⁺], and the concentration of the acid, [HA]. </em>
So, starting from the equations (2) and (3), the constant equation for the dissociation reaction of benzoic acid in water, of the equation (1), is:
![K_{a} = \frac{[C_{6}H_{5}COO^{-}][H_{3}O^{+}]}{[C_{6}H_{5}COOH]}](https://tex.z-dn.net/?f=%20K_%7Ba%7D%20%3D%20%5Cfrac%7B%5BC_%7B6%7DH_%7B5%7DCOO%5E%7B-%7D%5D%5BH_%7B3%7DO%5E%7B%2B%7D%5D%7D%7B%5BC_%7B6%7DH_%7B5%7DCOOH%5D%7D%20)
I hope it helps you!
