Embibe Experts Solutions for Chapter: Some Basic Concepts of Chemistry, Exercise 2: Exercise-2

A certain organic substance used as a solvent in many reactions contains carbon, hydrogen, oxygen and sulphur. Weight % of hydrogen in the compound is 7.7. The weight ratio C : O : S = 3 : 2 : 4. What is the least possible molar mass(in $\mathrm{g}$) of the compound ?

When $1 \mathrm{mole}$ of A reacts with $\frac{1}{2}\mathrm{mole}$ of B_{2$\left(\mathrm{A}+\frac{1}{2}{\mathrm{B}}_2\to \mathrm{AB}\right)$}, $100 \mathrm{kcal}$ heat is liberated and when $1 \mathrm{mole}$ of A reacted with $2 \mathrm{mole}$ of B₂ $\left(\mathrm{A}+2{\mathrm{B}}_2\to {\mathrm{AB}}_4\right)$, $200 \mathrm{kcal}$ heat is liberated. When of A is completely reacted with excess of B₂ to form AB as well as AB₄, $140 \mathrm{kcal}$ heat is liberated. Calculate the mole of B₂ used. [Write your answer as number of mole of B₂ used $\times 10$].

$100 \mathrm{ml}$ If of $1 \mathrm{M} {\mathrm{H}}_2{\mathrm{SO}}_4$ solution is mixed with $100 \mathrm{ml}$ of $98\%(\mathrm{w}/\mathrm{w}){\mathrm{H}}_2{\mathrm{SO}}_4$ solution $(\mathrm{d}=0.1\mathrm{gm}/\mathrm{ml})$ then :

A $100\mathrm{ml}$ mixture of $\mathrm{CO}$ and ${\mathrm{CO}}_2$ is passed through a tube containing red hot charcoal. The volume becomes $160\mathrm{ml}$. The volumes are measured under the same conditions of temperature and pressure. Amongst the following, select the correct statement(s).

A certain weight of pure ${\mathrm{CaCO}}_3$ is made to react completely with $20 \mathrm{mL}$ of a $\mathrm{HCl}$ solution to give $224$ $\mathrm{mL}$ of ${\mathrm{CO}}_2$ gas at $\mathrm{STP}.$ The normality of the $\mathrm{HCl}$ solution is:

What volume of $0.05\mathrm{MCa}{\left(\mathrm{OH}\right)}_2$ solution is needed for complete conversion of $10 \mathrm{mL}$ of $0.1{\mathrm{MH}}_3{\mathrm{PO}}_4$ into $\mathrm{Ca}{\left({\mathrm{H}}_2{\mathrm{PO}}_4\right)}_2?$

To a $25 \mathrm{ml} {\mathrm{H}}_2{\mathrm{O}}_2$ solution excess acidified solution of $\mathrm{Kl}$ was added. The iodine liberated $20 \mathrm{ml}$ of $0.3 \mathrm{N}$ sodium this sulphate solution. Use these data to choose the correct statements from the following :

There are two sample of $\mathrm{HCl}$ having molarity $1 \mathrm{N}$ and $0.25 \mathrm{N}.$ Find volume of these sample taken in order to prepare $0.75 \mathrm{N} \mathrm{HCl}$ solution. (Assume no water is used)