Auto Protolysis of Water

Q. Which of the following salts will give highest pH in water?

1. $KCl$
2. $NaCl$
3. $N{a}_{2}C{O}_3$
4. $CuS{O}_4$

Q. If 500 mL of a 5 M solution is diluted to 1500 mL, what will be the molarity of the solution obtained?

1. 1.59 M
2. 1.5 M
3. 0.017 M
4. 1.66 M

Q.

At ${25}^{\circ }$C the pH of a ${10}^{-8}$ molar solution of HCl in water is

1. Between 6 and 7

2. Between 7 and 8

3. 8

4. -8

Q.

The conjugate base for bronsted acids ${\mathrm{H}}_2\mathrm{O}$ and $\mathrm{HF}$ are?

1. ${\mathrm{OH}}^{-}$and ${\mathrm{H}}_2{\mathrm{F}}^{+}$

2. ${\mathrm{H}}_3{\mathrm{O}}^{+}$and ${\mathrm{F}}^{-}$

3. ${\mathrm{OH}}^{-}$and ${\mathrm{F}}^{-}$

4. ${\mathrm{H}}_3{\mathrm{O}}^{+}$and ${\mathrm{H}}_2{\mathrm{F}}^{+}$

Q.

If 1 mole of Potash alum is completely dissolved in water, how many moles of ions will be furnished?

Q. Molar conductance of $0.1M$ acetic acid is $7oh{m}^{-1}c{m}^{2}mo{l}^{-1}$. If the molar conductance of acetic acid at infinite dilution is $380.80oh{m}^{-1}c{m}^{2}mo{l}^{-1}$, the value of dissociation constant will be:

1. $2.26\times {10}^{-5}mold{m}^{-3}$

2. $1.66\times {10}^{-5}mold{m}^{-3}$

3. $1.66\times {10}^{-2}mold{m}^{-3}$
4. $3.4\times {10}^{-5}mold{m}^{-3}$

Q. The degree of dissociation of pure water at $25{}^{o}C$ is found to be $1.8\times {10}^{-9}$. Find $K_{w}and{K}_d$ at $25{}^{o}C$ ?

1. $3.24\times {10}^{-18}$ ; $5.83\times {10}^{-20}$
2. $1.00\times {10}^{-14}$ ; $1.80\times {10}^{-16}$
3. $1.80\times {10}^{-16}$ ; $1.00\times {10}^{-14}$
4. $1.00\times {10}^{-14}$ ; $1.00\times {10}^{-14}$

Q.

Name the three acid-base theory?

Q. The $pH$ of neutral water at ${25}^{\circ }\text{C}$ is $7.0$. What will be the nature of pure water at ${60}^{\circ }\text{C}$?

1. Acidic
2. Basic
3. Neutral
4. Cannot predict

Q.

Relative lowering of vapour pressure is a colligative property because _____________.

1. It depends on the number of particles of electrolyte solute in a solution and does not depend on the nature of the solute molecules.

2. It depends on the concentration of a non-electrolyte solute in a solution and does not depend on the nature of the solute molecules.

3. It depends on the concentration of an electrolyte or a non-electrolyte solute in solution as well as on the nature of solute molecules

4. It depends on the concentration of a non-electrolyte solute in solution as well as on the nature of the solute molecules.

Q.

Why is aniline soluble in aqueous $HCl?$

Q. Dry air was passed through a beaker solution containing $15\text{g}$ of solute and $120\text{g}$ of water. Then, it passed through a beaker containing pure water solvent. Loss in weight of the solution beaker was $2\text{g}$ and loss in weight of solvent beaker was $0.05\text{g}$. What is the molecular weight of the solute ?

1. $95\text{g/mol}$
2. $85\text{g/mol}$
3. $90\text{g/mol}$
4. $100\text{g/mol}$

Q. The following equilibrium in established when hydrogen chloride is dissolved in acetic acid.
$HCl+C{H}_{3}COOH\rightleftharpoons C{l}^{-}+C{H}_{3}COO{H}_2^{+}$
The set that characterises the conjugate acid-base pairs is

1. $(HCl,C{H}_{3}COOH)\text{and}(C{H}_{2}COO{H}_2^{+},C{l}^{-})$
2. $(HCl,C{H}_{3}COO{H}_2^{+})\text{and}(C{H}_{3}COOH,C{l}^{-})$
3. $(C{H}_{3}COO{H}_2^{+},HCl)\text{and}\left(C{l}^{-}C{H}_{3}COOH\right)$
4. $(HCl,C{l}^{-})\text{and}(C{H}_{3}COO{H}_2^{+},C{H}_{3}COOH)$

Q.

Which of the following is a strong base?

1. Acetic acid

2. Hydrochloric acid

3. Sodium bicarbonate

4. Sodium hydroxide

Q. What is the hydrolysis constant of a weak acid-weak base?

1. $K_w/K_b$
2. $K_w/K_a$
3. $K_w/K_a{K}_b$
4. $1/K_a{K}_b$

Q. Calculate amount of ammonium chloride required to dissolve in 500 ml water to make pH = 4.5
$(K_{b}forN{H}_3=1.8\times {10}^{-5})$

1. 48.15 gm
2. 47.15 gm
3. 48.12 gm
4. 48.18 gm

Q. How is heavy water prepared? Compare its physical properties with those of ordinary water.

Q.

The ionic product of water will increase if

1. temperature is reduced

2. temperature is increased

3. pressure is decreased

4. pressure is increased

Q.

Is $\mathrm{NaCl}$ it an Arrhenius acid or base?

Q.

Which salt has highest $\mathrm{pH}$ in water?

Q. Select the correct option from the following ?

1. $p{K}_w$ increases with increase in temperature
2. $p{K}_w$ decreases with increase in temperature
3. $p{K}_w=14$ at all temperature
4. $p{K}_w=pH$ at all temperature

Q.

The pH of rain water collected from two cities A and B was found to be 6 and 5 respectively. The rain water of which city is more acidic?

Q. Which of the following can be classified as autoprotolysis reactions?

1. $H_{2}O\left(l\right)+H_{2}O\left(l\right)\rightleftharpoons H_3{O}^{+}\left(aq\right)+O{H}^{-}\left(aq\right)$
2. $2N{H}_3\left(l\right)\rightleftharpoons N{H}_4^{+}\left(aq\right)+N{H}_2^{-}\left(aq\right)$
3. $C{H}_{3}COOH\left(aq\right)\rightleftharpoons C{H}_{3}CO{O}^{-}\left(aq\right)+H^{+}\left(aq\right)$
4. $2C{H}_{3}COOH\left(l\right)\rightleftharpoons C{H}_{3}CO{O}^{-}\left(aq\right)+C{H}_{3}COO{H}_2^{+}\left(aq\right)$

Q.

Arrhenius neutralization is described as

1. formation of dative bond

2. proton transfer from base to acid

3. formation of water

4. proton transfer from acid to base

Q.

Which of the following represents conjugate acid-base pair?

1. ${\mathrm{H}}_3{\mathrm{O}}^{+}\mathrm{and}{\mathrm{H}}_2\mathrm{O}$

2. ${\mathrm{H}}_2{\mathrm{SO}}_4\mathrm{and}{{\mathrm{SO}}_4}^{2-}$

3. ${{\mathrm{HCO}}_3}^{-}\mathrm{and}{{\mathrm{CO}}_3}^{2-}$

4. All are conjugate acid/base pairs

Q.

Give one example each of the following:

Insoluble salt

Q.

Which one of the following is acid salt?

1. ${\mathrm{Na}}_2\mathrm{S}$

2. ${\mathrm{Na}}_2{\mathrm{SO}}_3$

3. ${\mathrm{NaHSO}}_3$

4. ${\mathrm{Na}}_2{\mathrm{SO}}_4$

Q.

What do you understand by the term ’auto-protolysis’ of water? What is its significance?

Q.

Taking sodium carbonate as an example, give the meaning of the following terms:

(a) Water of crystallization

Q. Consider a solution having $\left[H^{+}\right]={10}^{-5}M$ at ${25}^{\circ }C$, then $O{H}^{-}$ ion concentration of this solution at the given temperature is :

1. ${10}^{-5}M$
2. ${10}^{-9}M$
3. ${10}^{-10}M$
4. ${10}^{-8}M$