Embibe Experts Solutions for Chapter: Mole Concept - 2, Exercise 2: KVPY PROBLEMS (PREVIOUS YEARS)

When $1.88 \mathrm{g}$ of $\mathrm{AgBr}\left(\mathrm{s}\right)$ is added to a ${10}^{-3} \mathrm{M}$ aqueous solution of $\mathrm{KBr},$ the concentration of ${\mathrm{Ag}}^{+}$ is $5\times {10}^{-10} \mathrm{M}$ if the same amount of $AgBr\left(\mathrm{s}\right)$ is added to a ${10}^{-2} \mathrm{M}$ aqueous solution of ${\mathrm{AgNO}}_3,$ the concentration of ${\mathrm{Br}}^{-}$ is:

The amount of $\mathrm{Ag}$ (atomic mass $=108$) deposited at the cathode when a current of $0.5 \mathrm{amp}$ is passed through a solution of ${\mathrm{AgNO}}_3$ for $1$ hour is closest to:

A $1.85 \mathrm{g}$ sample of an arsenic-containing pesticide was chemically converted to ${\mathrm{AsO}}_4^{3-}$ (atomic mass of $\mathrm{As}=74.9$) and titrated with ${\mathrm{Pb}}^{2+}$ to form ${\mathrm{Pb}}_3{\left({\mathrm{AsO}}_4\right)}_2$. If $20 \mathrm{mL}$ of $0.1 \mathrm{M} {\mathrm{Pb}}^{2+}$ is required to reach the equivalence point, the mass percentage of arsenic in the pesticide sample is closest to

$\mathrm{Xg}$ of $\mathrm{Ca}$ [atomic mass $=40$] dissolves completely in concentrated $\mathrm{HCl}$ solution to produce $5.40 \mathrm{L}$ of ${\mathrm{H}}_2$ gas at $\mathrm{STP}$. The value of $\mathrm{X}$ is the closest to

In a closed vessel, at $\mathrm{STP}, 50 \mathrm{L} {\mathrm{CH}}_4$ is ignited with $750 \mathrm{L}$ of air(containing $20\%{\mathrm{O}}_2$). The number of moles of ${\mathrm{O}}_2$ remaining in the vessel on cooling to room temperature is closest to

${\mathrm{KMnO}}_4$ reacts with ${\mathrm{H}}_2{\mathrm{O}}_2$ in an acidic medium. The number of moles of oxygen produced per mole of ${\mathrm{KMnO}}_4$ is:

Which of the following is NOT an oxidation-reduction reaction ?

The formal oxidation number of $\mathrm{Cr}$ and $\mathrm{Cl}$ in the ions ${\mathrm{Cr}}_2{\mathrm{O}}_7^{2-}$ and ${\mathrm{ClO}}_3^{-},$ respectively, are: