Embibe Experts Solutions for Chapter: Some Basic Concepts of Chemistry, Exercise 1: KCET (UG) 2020

A pure compound contains $2.4 \mathrm{g}$ of $\mathrm{C},1.2\times {10}^{23}$ atoms of $\mathrm{H},0.2$ moles of oxygen atoms. Its empirical formula is

$0.4 \mathrm{g}$ of dihydrogen is made to react with $7.1 \mathrm{g}$ of dichlorine to form hydrogen chloride. The volume of hydrogen chloride formed at $273 \mathrm{K}$ and $1 \mathrm{bar}$ pressure is

How many moles of acidified ${\mathrm{K}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7$ is required to liberate $6$ moles of ${\mathrm{I}}_2$ from an aqueous solution of ${\mathrm{I}}^{-}$?

The mass of $\mathrm{AgCl}$ precipitated when a solution containing $11.70 \mathrm{g}$ of $\mathrm{NaCl}$ is added to a solution containing $3.4 \mathrm{g}$ of ${\mathrm{AgNO}}_3$ is [Atomic mass of $\mathrm{Ag}=108$, Atomic mass of $\mathrm{Na}=23$]

$1.0 \mathrm{g}$ of $\mathrm{Mg}$ is burnt with $0.28 \mathrm{g}$ of ${\mathrm{O}}_2$ in a closed vessel. Which reactant is left in excess and how much?

A gas mixture contains $25\%$ $\mathrm{He}$ and $75\% {\mathrm{CH}}_4$ by volume at a given temperature and pressure. The percentage by mass of methane in the mixture is approximately ___ .