Lawrie Ryan and Roger Norris Solutions for Chapter: Atoms, Molecules and Stoichiometry, Exercise 28: EXAM-STYLE QUESTIONS

Calcium oxide reacts with hydrochloric acid according to the equation:

$\mathrm{CaO}+2\mathrm{HCl}\to {\mathrm{CaCl}}_2+{\mathrm{H}}_2\mathrm{O}$.

${\mathrm{A}}_{\mathrm{r}}$ values: $\mathrm{H}=1.0; \mathrm{O}=16.0; \mathrm{Cl}=35.5; \mathrm{Ca}=40.1$

Calculate the mass of water produced when $28.05 \mathrm{g}$ calcium oxide reacts with excess of hydrochloric acid.

When ammonia gas and hydrogen chloride gas mix together, they react to form a solid called ammonium chloride.

${\mathrm{A}}_{\mathrm{r}}$ values: $\mathrm{H}=1.0; \mathrm{N}=14.0; \mathrm{Cl}=35.5$

Write a balanced equation for this reaction, including state symbols.

When ammonia gas and hydrogen chloride gas mix together, they react to form a solid called ammonium chloride.

${\mathrm{A}}_{\mathrm{r}}$ values: $\mathrm{H}=1.0; \mathrm{N}=14.0; \mathrm{Cl}=35.5$

Calculate the molar masses of ammonia, hydrogen chloride and ammonium chloride.

When ammonia gas and hydrogen chloride gas mix together, they react to form a solid called ammonium chloride.

${\mathrm{A}}_{\mathrm{r}}$ values: $\mathrm{H}=1.0; \mathrm{N}=14.0; \mathrm{Cl}=35.5$

Calculate the volumes of ammonia and hydrogen chloride gases that must react at r.t.p in order to produce $10.7 \mathrm{g}$ of ammonium chloride?

($1 \mathrm{mol}$ of gas occupies $24 {\mathrm{dm}}^3$ at r.t.p.).

The mass spectrum of an organic compound with the structure ${\mathrm{CH}}_3{\mathrm{CH}}_2{\mathrm{CH}}_2{\mathrm{CH}}_3$ is shown.

Identify the fragments with mass/charge ratios of 

i. $15$    ii. $29$   iii. $43$   iv. $58$

An organic compound, $\mathrm{Z}$, has a molecular ion peak, $\mathrm{M}$, with a reactive abundance of $36.4\%$ and an $\left[\mathrm{M}+1\right]$ peak with a relative abundance of $4.8\%$. Deduce the number of carbon atoms this compound contains.

The mass spectrum of chlorobutane shows an $\left[\mathrm{M}+2\right]$ peak beyond the ${\mathrm{M}}_{\mathrm{r}}$ peak. Explain why there is an $\left[\mathrm{M}+2\right]$ peak.

The relative height of the $\left[\mathrm{M}+2\right]$ peak in organic compound $\mathrm{T}$ is the same as that of the ${\mathrm{M}}_{\mathrm{r}}$ peak. Explain how this shows that the compound contains one atom of bromine and not one atom of chlorine.