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.

Assertion : ${\mathrm{H}}_2{\mathrm{O}}_2$ has higher boiling point than water.

Reason : The dipole moment of ${\mathrm{H}}_2{\mathrm{O}}_2$ is little more than that of ${\mathrm{H}}_2\mathrm{O}$.

Assertion : Beryllium hydride is a covalent hydride.

Reason : The electronegativity difference between $\mathrm{Be}$ and $\mathrm{H}$ is very high.

Assertion : The $\mathrm{O}-\mathrm{O}$ bond length of ${\mathrm{H}}_2{\mathrm{O}}_2$ is shorter than that of ${\mathrm{O}}_2{\mathrm{F}}_2.$

Reason : ${\mathrm{H}}_2{\mathrm{O}}_2$ is an ionic compound.

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