100 ml of a sample of hard water required 25.1 ml of 0.02 (N) ${\mathrm{H}}_2{\mathrm{SO}}_4$ for complete reaction. What is the hardness of the given water sample ? (sp. gravity of given water sample = 1 gm/ml)

(A) 200 ppm                                 

(B) 250 ppm

(C) 251 ppm                                 

(D) 258 ppm

A mixture of hydrazine $\left({\mathrm{N}}_2{\mathrm{H}}_4\right)$ and $58-60\%$ solution of ${\mathrm{H}}_2{\mathrm{O}}_2$ is used as.

(1) Antiseptic                     

(2) Fertilizer

(3) Rocket fuel                   

(4) None

50 lit of hard water of 120 ppm temporary hardness is mixed with 1.62 kg of $\mathrm{Ca}{\left(\mathrm{OH}\right)}_2,$ what is the hardness of the resulting water ? (The sp. gr. of hard water = 1 gm/ml)

(A) 8.088 × 10⁵ ppm                               

(B) 8.088 × 10⁴ ppm

(C) 80 ppm                                             

(D) 808 ppm

Commercially ${\mathrm{H}}_2{\mathrm{O}}_2$ is now prepared by –

(A) Action of ${\mathrm{H}}_2{\mathrm{SO}}_4$ on barium peroxide

(B) Action of ${\mathrm{H}}_2{\mathrm{SO}}_4$ on sodium peroxide

(C) Electrolysis of ${\mathrm{H}}_2{\mathrm{SO}}_4$

(D) By burning hydrogen in excess of oxygen

A sample of hard water was found to contain 68 ppm of ${\mathrm{CaSO}}_4$ and 19 ppm of ${\mathrm{MgCl}}_2$. Its total hardness is –

(1) 70 ppm                             

(2) 50 ppm

(3) 20 ppm                             

(4) 100 ppm

A certain sample of hydrogen peroxide is 1.5M solution. It is to be labelled as X volumes. Calculate the value of X.

(1) 16.8 L                             

(2) 11.8 L

(3) 5.3 L                               

(4) 6.2 L

Find the volume strength of $1.6 \mathrm{N} {\mathrm{H}}_2{\mathrm{O}}_2$ solution.

1. 8.96                               

2. 2.16

3. 9.16                               

4. 5.14

What mass of hydrogen peroxide is present in 2 litre solution of 4M strength ? Calculate the volume of oxygen at S.T.P. liberated upon complete decomposition of 400 ${\mathrm{cm}}^3$ of the above solution.

(A) 172g, 0.92 L                                   

(B) 272g, 1.32 L

(C) 272g, 17.92 L                                 

(D) 172g, 15.14 L

30ml of a ${\mathrm{H}}_2{\mathrm{O}}_2$ solution after acidification required 30ml of $\mathrm{N}/10$ ${\mathrm{KMnO}}_4$ solution for complete oxidation. Calculate the percentage and volume strength of ${\mathrm{H}}_2{\mathrm{O}}_2$ solution.

(A) 2.17%, 2.56                         

(B) 0.17%, 0.56

(C) 5.12%, 3.16                         

(D) 3.12%, 0.86

Assertion:  ${\mathrm{D}}_2\mathrm{O}$ is called heavy water.

Reason : Its degree of dissociation is high.