B S Bisht, R D Madan and, Nelson A Petrie Solutions for Chapter: The Language of Chemistry, Exercise 1: Questions

Define molecular formula of a compound. Give one example.

Which of the following are the molecular formulae?

${\mathrm{N}}_2{\mathrm{O}}_4$, ${\mathrm{Cr}}_2{\mathrm{O}}_3$, ${\mathrm{H}}_2{\mathrm{S}}_2{\mathrm{O}}_3$, ${\mathrm{H}}_2{\mathrm{C}}_2{\mathrm{O}}_4$

Solid ammonium dichromate (relative molecular mass 252) decomposes as under:
$({\mathrm{NH}}_4{)}_2{\mathrm{Cr}}_2{\mathrm{O}}_7\to {\mathrm{N}}_2+{\mathrm{Cr}}_2{\mathrm{O}}_3+4{\mathrm{H}}_2\mathrm{O}$

Calculate the mass of $63\mathrm{g}$of chromium $\left[\mathrm{III}\right]$ oxide formed at the same time.

The compound A has the following percentage composition by mass: Carbon $26.7\%$, Oxygen $71.1\%$, Hydrogen $2.2\%$. Determine the empirical formula of A (Work to one decimal place) $(\mathrm{H}=1,\mathrm{C}=12,\mathrm{O}=16)$. If the relative molecular mass of $\mathrm{A}$ is $90$, what is the molecular formula of $\mathrm{A}$?

Ammonia burns in oxygen and the combustion, in the presence of a catalyst, may be represented by

$2{\mathrm{NH}}_3+\frac{5}{2}{\mathrm{O}}_2\to 2\mathrm{NO}+3{\mathrm{H}}_2\mathrm{O}\left(\mathrm{H}=1,\mathrm{N}=14,\mathrm{O}=16\right)$

What mass of steam is produced when $1.5\mathrm{g}$ of nitrogen monoxide is formed?

The molecular formula of an organic acid is ${\mathrm{H}}_2{\mathrm{CO}}_2$. What is its empirical formula?

A compound has the following percentage composition: Hydrogen $2.2\%$, Carbon $26.6\%$ and Oxygen $71.2\%$. Calculate the empirical formula of the compound. If its molecular weight is $90$, find its molecular formula. $(\mathrm{H} = 1, \mathrm{C} = 12,0 =16)$

A compound of sodium, sulphur and oxygen has the following percentage composition: $\mathrm{Na}=29.11\%,\mathrm{S}=40.51\%,\mathrm{O}=30.38\%$. Find its empirical formula $(\mathrm{O}= 16,\mathrm{Na} = 23, \mathrm{S} = 32)$.