Buffer Solutions

Q. Arrange them in the order of increasing ionic radii.
N3+, O2-, F-, Na+, Mg2+, and Al3+

Q.

What is a Buffer Capacity?

Q.

Which of the following is not a buffer solution?

1. $(\mathrm{HCl}/\mathrm{NaCl})$

2. $({\mathrm{NH}}_4\mathrm{OH}/{\mathrm{NH}}_4\mathrm{Cl})$

3. $(\mathrm{HCOOH}/\mathrm{HCOONa})$

4. $({\mathrm{CH}}_3\mathrm{COOH}/{\mathrm{CH}}_3\mathrm{COONa})$

Q.

How does a mixture of ${\mathrm{CH}}_3\mathrm{COOH}$ and ${\mathrm{CH}}_3\mathrm{COONa}$ act as a buffer when a small amount of $\mathrm{NaOH}$ is added?

Q.

$\mathrm{pH}$ of an aqueous solution of$0.1\mathrm{M}$ ${\mathrm{NH}}_4\mathrm{Cl}$ solution is : $({\mathrm{pK}}_{\mathrm{b}}{\mathrm{NH}}_4\mathrm{OH}=4.7)$.

Q.

How Do You Know If A Solution Is A Buffer?

Q.

Why cant a strong acid be a buffer?

Q.

What makes a good buffer solution?

Q. Which of the following can be used as a buffer solution?

1. A solution containing $NaCl$ and $NaOH$.
2. A solution containing $NaCl$ and $N{H}_{4}OH$.
3. A solution containing sodium acetate.
4. A solution containing ammonium acetate.

Q.

Fear or excitement generally causes one to breathe rapidly and it results in a decrease in ${\mathrm{CO}}_2$ concentration in the blood. In what way will it change the pH of blood?

1. pH will increase

2. pH will decrease

3. No change

4. pH will be 7

Q. Buffer solutions have constant acidity and alkalinity because :

1. They have fixed value of $pH$
2. They have large excess $H^{+}$ or $O{H}^{-}$ ions
3. These give unionised acid on reaction with added acid or ionised acid on reaction with alkali
4. Acids and bases in these solution are shielded from attack by other ions

Q. $p{K}_b$ for $N{H}_{4}OH$ at certain temperature is $4.74$. The $pH$ of basic buffer containing equimolar concentration of $N{H}_{4}OH$ and $N{H}_{4}Cl$ will be :

1. $9.26$
2. $4.74$
3. $7.74$
4. $2.37$

Q. Which of the following will form a buffer solution?
(a) $C{H}_{3}COONa+C{H}_{3}COOH$
(b) $NaCl+NaOH$
(c) $N{H}_{4}Cl+N{H}_{4}OH$
(d) $N{a}_{2}S{O}_4+H_{2}S{O}_4$

1. A, B
2. B, C
3. A, D
4. A, C

Q. Total numbers of buffers can be made by reaction of $H_{3}P{O}_4$ and $NaOH$ is

1. 3
2. 1
3. 4
4. 2

Q. Which of the following solutions will show positive deviation from Raoult's law?

1. Water and ethanol
2. Acetone and $C{S}_2$
3. Acetone and benzene
4. All of the above

Q.

How do you calculate the pH of HCl? Explain with example.

Q.

How do you calculate the$\mathrm{pH}$ of acetic acid? Give an example

Q. The drug given during hypertension is:

1. Streptomycin
2. Chloroxylenol
3. Equanil
4. Aspirin

Q.

Assertion: Sodium hydrogen-carbonate is an acidic salt.

Reason: The pH of an aqueous solution of Sodium Hydrogen-carbonate is more than 7.0.

1. Assertion is true and the reason is false.

2. Assertion is false and the reason is true.

3. Both Assertion and Reason are true. The reason is the correct explanation of assertion.

4. Both Assertion and Reason are true. The reason is not the correct explanation of assertion.

Q. Aqueous solution of $HN{O}_3$, $KOH,C{H}_{3}COOH$ and $C{H}_{3}COONa$ of identical cocenteration are provided. The pair (s) of solution which forms buffer upon mixing is (are)

1. $HN{O}_3$ and $C{H}_{3}COOH$
2. $KOHandC{H}_{3}COONa$
3. $HN{O}_3$ and $C{H}_{3}COONa$
4. $C{H}_{3}COOHandC{H}_{3}COONa$

Q.

Explain what is a buffer solution.

Q.

The ionization constant of benzoic acid is $6.46\times {10}^{-5}$ and Ksp for silver benzoate is $2.5\times {10}^{-13}$. How many times is silver benzoate more soluble in a buffer of pH 3.19 compared to its solubility in pure water?

Q. Find the pH of 10^-6 M and 10^-8 M of HCl

Q. For propanoic acid $K_a=1.34\times {10}^{-5}\text{M}$ at ${25}^{\circ }\text{C}$. Then what will be the degree of dissociation for a $0.01\text{M}$ solution of the acid ?

1. $3.66\times {10}^{-4}$
2. $3.66\times {10}^{-2}$
3. $5\times {10}^{-4}$
4. $5\times {10}^{-2}$

Q. What volume of $0.1M$ sodium formate solution should be added to 50 mL of $0.05M$ formic acid to produce a buffer solution of $pH=4.0$; $p{K}_a$ of formic acid $=3.80$ ?

1. 3.96 mL
2. 39.6 mL
3. 45 mL
4. 35.6 mL

Q. Which one of the following is natural buffer ?

1. Blood
2. River water
3. (a) and (b) above.
4. None of the above

Q. In some solutions, the concentration of $H_3{O}^{+}$ remains constant even when small amounts of strong acid or strong base are added to them. These solutions are known as:

1. Colloidal solutions
2. True solutions
3. Ideal solutions
4. Buffer solutions

Q. Which one of the following is salt buffer ?

1. $\left(N{H}_{4}CN\right)$ solution
2. $(C{H}_{3}COON{H}_4,)$ solution
3. (a) and (b) above.
4. None of the above

Q. $0.1$ mole arsenic acid $\left(H_{3}As{O}_4\right)$ is dissolved in a 1L buffer solution of $pH=8$. Which of the following options is/are correct? For arsenic acid: $K{a}_1=2.5\times {10}^{-4},K{a}_2=5\times {10}^{-8},K{a}_3=2\times {10}^{-13}$.
(‘<<’ sign denotes that the higher concentration is 100 times greater than the lower one or more)

1. $\left[H_{3}As{O}_4\right]<<\left[H_{2}As{O}_4^{-}\right]$
2. $\left[H_{2}As{O}_4^{-}\right]<<\left[HAs{O}_4^{2-}\right]$
3. $\left[HAs{O}_4^{2-}\right]<<\left[H_{2}As{O}_4^{-}\right]$
4. $\left[As{O}_4^{3-}\right]<<\left[HAs{O}_4^{2-}\right]$

Q. Total numbers of buffers can be made by reaction of $H_{3}P{O}_4$ and $NaOH$ is

1. 1
2. 4
3. 2
4. 3