Enthalpy of Neutralisation

Q. The enthalpy of transition of C(diamond) to C(graphite) is (Given that the enthalpies of combustion of C(diamond) and C(graphite) are – 393.5 and – 395.4 kJ $mo{l}^{-1}$ respectively)

1. + 1.9 kJ
2. - 1.9 kJ
3. 3.8 kJ
4. - 3.8 kJ

Q.

The enthalpy of neutralization of $HCl$ and $NaOH$ is $-57kJmo{l}^{-1}$. The heat evolved at constant pressure (in kJ) when $0.5mole$ of H2SO4 react with $0.75mole$ of $NaOH$ is equal to

1. 57 x 3/4

2. 57 x 0.5

3. 57

4. 57 x 0.25

Q. The heat of neutralisation is maximum when

1. Sodium hydroxide is neutralised by hydrochloric acid

2. Ammonium hydroxide is neutralised by hydrochloric acid

3. Sodium hydroxide is neutralised by acetic acid

4. Ammoniym hydroxide is neutralised by acetic acid

Q.

At a particular temperature $H^{+}\left(aq\right)+O{H}^{-}\left(aq\right)\to H_{2}O\left(l\right);\Delta H=-57.1kJ$. The approximate heat evolved when $400mL$ of $0.2$ $H_{2}S{O}_4$ is mixed with $600mL$ of $0.1m$ $KOH$ solution will be:

1. 3.42kJ

2. 13.7 kJ

3. 5.2kJ

4. 55kJ

Q. ntwhat is the difference between reaction taking place in acidic medium , basic medium and neutral medium?n

Q. 58.One c.c of phosphoric acid was diluted to 250 cc; 25cc of this solution required 34. 8 CC of 0. 102N NaoH for neutralization, using phenolphthalein as indicator. What is the specific gravity of the acid?

Q. One mole of each methonoic acid and sodium hydroxide are mixed. If x is the heat released during formation of water from $H^{+}$ and $O{H}^{-}$, the heat evolved in the above neutralization is:

1. More than x
2. Equal to x
3. Less than x
4. Twice that of x

Q.

At a particular temperature $H^{+}\left(aq\right)+O{H}^{-}\left(aq\right)\to H_{2}O\left(l\right);\Delta H=-57.1kJ$. The approximate heat evolved when $400mL$ of $0.2$ $H_{2}S{O}_4$ is mixed with $600mL$ of $0.1m$ $KOH$ solution will be:

1. 3.426kJ

2. 13.7kJ

3. 5.2 kJ

4. 55kJ

Q. Enthalpy of neutralization of HCl with NaOH is x. The heat evolved when 500 ml of 2N HCl is mixed with 250 ml of 4N NaOH will be

1. 500 x
2. 100 x
3. x
4. 10 x

Q.

31. In permutit process, what is the role of addition of the concentrated solution of solid compound obtained due to the reaction between NaOH and HCl.

Q. Heat of neutralization of strong acid against strong base is constant and is equal to

1. 13.7 kcal

2. 57 kJ

3. 5.7×10⁴ J

4. All of the above

Q.

The enthalpy of neutralization of $HCl$ and $NaOH$ is $-57kJmo{l}^{-1}$. The heat evolved at constant pressure (in kJ) when $0.5mole$ of H2SO4 react with $0.75mole$ of $NaOH$ is equal to

1. $57\times \frac{3}{4}$

2. $57\times 0.5$

3. $57$

4. $57\times 0.25$

Q. 7.125g of an acid (MW=114) is completely neutrilized by 5g of NaOH (MW=40). What is the basicity of acid?

Q. Which of the following reactions have maximum heat of neutralisation?

1. $N{H}_{4}OHandC{H}_{3}OOH$
2. $N{H}_{4}OHandHCl$
3. $NaOHandC{H}_{3}OOH$
4. $NaOHandHCl$

Q. Enthalpy of neutralization of $H_{3}P{O}_3$ acid is -106.68 kJ/mol using $NaOH$. If enthalpy of neutralization of $HCl$ by $NaOH$ is -55.84 kJ/mol.
Calculate $△H_{ionization}of{H}_{3}P{O}_3$ into its ions:

1. 50.84 kJ/mol
2. 5 kJ/mol
3. 2.5 kJ/mol
4. None of these

Q. Match the following (Assume heat of neutralisation of strong acid with strong base is 13.7 kcal):

$\begin{array}{cccc}& \text{Column - I}& & \text{Column - II}\\ & \text{(Enthalpy change in kcal)}& & \text{(Neutralisation)}\\ \text{(A)}& <13.7\text{kcal}& \text{(p)}& \underset{\left(1mol\right)}{HCl}+\underset{\left(1mol\right)}{NaOH}\\ \text{(B)}& =13.7\text{kcal}& \text{(q)}& \underset{\left(1mol\right)}{HF}+\underset{\left(1mol\right)}{NaOH}\\ \text{(C)}& >13.7\text{kcal}& \text{(r)}& \underset{\left(1mol\right)}{N{H}_{4}OH}+\underset{\left(1mol\right)}{HCl}\\ \text{(D)}& =27.4\text{kcal}& \text{(s)}& \underset{\left(2mol\right)}{NaOH}+\underset{\left(1mol\right)}{H_{2}S{O}_4}\\ & & \text{(t)}& \underset{\left(1mol\right)}{NaOH}+\underset{\left(1mol\right)}{C{H}_{3}COOH}\end{array}$

1. a - r, t
   b - p
   c - q, s
   d - s
2. a - r, t, s
   b - p
   c - q,
   d - s
3. a - r, t, s
   b - p, s
   c - q, s
   d - s
4. a - r, t
   b - p, s
   c - q, s
   d - p

Q. Enthalpy of neutralization of $H_{3}P{O}_3$ acid is -106.68 kJ/mol using $NaOH$. If enthalpy of neutralization of $HCl$ by $NaOH$ is -55.84 kJ/mol.
Calculate $△H_{ionization}of{H}_{3}P{O}_3$ into its ions:

1. 50.84 kJ/mol
2. 5 kJ/mol
3. 2.5 kJ/mol
4. None of these

Q. Calculate the enthalpy change when $50mL$ of $0.01M$ $Ca(OH{)}_2$ reacts with $25mL$ of $0.01M$ $HCl$. Given that $\Delta H^o$ of neutralization of a strong acid and a strong base is $14kcalmo{l}^{-1}$

1. $6.4cal$
2. $9.4cal$
3. $3.5cal$
4. $1.4cal$

Q. How many moles of hydrochloric acid will be required to neutralize exactly 80 gram of sodium hydroxide?

Q. The heat of neutralization of HCl by NaOH is -55.9 kJ mol${}^{-1}$. If the heat of neutralization of HCN by NaOH is -12.1 kJ/mol, the energy of dissociation of HCN is:

1. -43.8 kJ
2. 43.8 kJ
3. 68 kJ
4. -68 kJ

Q. $50.0mL$ of $0.10MHCl$ is mixed with $50.0mL$of $0.10MNaOH$. The solution's temperature rises by ${0.6}^{o}C.$ Calculate the enthalpy of neutralization per mole of $HCl$.
Given : density and specific heat of solution is $1gm{L}^{-1}$ and 4.2 $J{g}^{-1\circ }{C}^{-1}$

1. $-50.4kJ/mol$
2. $-54.4kJ/mol$
3. $-57.7kJ/mol$
4. $-63.2kJ/mol$

Q. Equal volumes of 1M HCl& 1M $H_{2}S{O}_4$ are neutralized by 1M NaOH solution and x & y KJ/equivalent of heat are liberated respectively. Which of the following relations is correct?

1. x = 2y

2. x = 3y

3. x = 4y

4. x = $\frac{1}{2}$ y

Q. In which of the following cases of mixing of a strong acid and a strong base each of 1 N concentration would the temperature increase of the solution be the same (assume heat evolved in neutralisation is only used up to increase the temperature of the solution)?

1. 20 mL acid and 30 mL alkali
2. 10 mL acid and 10 mL alkali
3. 35 mL add and 15 mL alkali
4. 50 mL acid and 50 mL alkali

Q. The enthalpy of neutralization of a weak monoprotic acid ($HA$) in $1M$ solution with a strong base is $-55.95kJ/mol.$ If the unionized acid requires $1.4kJ/mol$ heat for its complete ionization and enthalpy of neutralization of the strong monobasic acid with a strong monoacidic base is $-57.3kJ/mol.$ What is the % ionization of the weak acid in molar solution?

1. 1.5%
2. 3.57%
3. 35.7%
4. 10%

Q. The heat of neutralisation is maximum when

1. Sodium hydroxide is neutralised by acetic acid
2. Ammoniym hydroxide is neutralised by acetic acid
3. Ammonium hydroxide is neutralised by hydrochloric acid
4. Sodium hydroxide is neutralised by hydrochloric acid

Q. How many moles of hydrochloric acid will be required to neutralize exactly 80 gram of sodium hydroxide?

Q. Equimolar solutions of HCl and NaOH are neutralized with one another. The enthalpy released in the process is approximately

1. 57.1 kJ/eq.
2. 5.71 kJ/eq.
3. 0.571 kJ/eq.
4. 571 kJ/eq.

Q. The heats of neutralization of four acids A, B, C and D against a common alkali are 13.7, 9.4, 11.2 and 12.4 kcal/equivalent respectively. The weakest acid is

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

Q.

The enthalpy of neutralization of $HCl$ and $NaOH$ is $-57kJmo{l}^{-1}$. The heat evolved at constant pressure (in kJ) when $0.5mole$ of H2SO4 react with $0.75mole$ of $NaOH$ is equal to

1. $57\times \frac{3}{4}$

2. $57\times 0.5$

3. $57$

4. $57\times 0.25$

Q. What is the molarity of 1N H2SO4 solution?