Hydrocarbons are compounds of carbon and hydrogen only. Hydrocarbon $\mathrm{Z}$ is composed of $80\%$ carbon and $20\%$ hydrogen.

a. Calculate the empirical formula of hydrocarbon $\mathrm{Z}$. (${\mathrm{A}}_{\mathrm{r}}$ values: $\mathrm{C}=12.0, \mathrm{H}=1.0$).

b. The molar mass of hydrocarbon $\mathrm{Z}$ is $30.0 \mathrm{g} {\mathrm{mol}}^{-1}$. Deduce the molecular formula of this hydrocarbon.

When $50 {\mathrm{cm}}^3$ of hydrocarbon $\mathrm{Y}$ is burnt, it reacts with exactly $300 {\mathrm{cm}}^3$ of oxygen to form $200 {\mathrm{cm}}^3$ of carbon dioxide. Water is also formed in the reaction. Construct the equation for this reaction. Explain your reasoning.

Propane has the molecular formula ${\mathrm{C}}_3{\mathrm{H}}_8$. Calculate the mass of $600 {\mathrm{cm}}^3$ of propane at r.t.p. ($1 \mathrm{mol}$ of gas occupies $24 {\mathrm{dm}}^3$ at r.t.p.).

(${\mathrm{A}}_{\mathrm{r}}$ values: $\mathrm{C}=12.0, \mathrm{H}=1.0$).

When sodium reacts with titanium chloride $\left({\mathrm{TiCl}}_4\right)$, sodium chloride $\left(\mathrm{NaCl}\right)$ and titanium $\left(\mathrm{Ti}\right)$ are produced. Construct the balanced symbol equation for the reaction.

When sodium reacts with titanium chloride $\left({\mathrm{TiCl}}_4\right)$, sodium chloride $\left(\mathrm{NaCl}\right)$ and titanium $\left(\mathrm{Ti}\right)$ are produced. Calculate the mass of titanium produced from $380 \mathrm{g}$ of titanium chloride. Give your answer to $3$ significant figures. (${\mathrm{A}}_{\mathrm{r}}$ values: $\mathrm{Ti}=47.9, \mathrm{Cl}=35.5$).

When sodium reacts with titanium chloride $\left({\mathrm{TiCl}}_4\right)$, sodium chloride $\left(\mathrm{NaCl}\right)$ and titanium $\left(\mathrm{Ti}\right)$ are produced. Calculate the mass of titanium produced using $46.0 \mathrm{g}$ of sodium. Give your answer to $3$ significant figures. (${\mathrm{A}}_{\mathrm{r}}$ value: $\mathrm{Na}=23.0$).

In this question give all answers to $3$ significant figures. The reaction between $\mathrm{NaOH}$ and $\mathrm{HCl}$ can be written as:

$\mathrm{HCl}+\mathrm{NaOH}\to \mathrm{NaCl}+{\mathrm{H}}_2\mathrm{O}$

In this reaction, $15.0 {\mathrm{cm}}^3$ of hydrochloric acid was neutralised by $20.0 {\mathrm{cm}}^3$ of $0.0500 \mathrm{mol} {\mathrm{dm}}^{-3}$ sodium hydroxide. Calculate the volume in ${\mathrm{dm}}^3$ of the acid. 

In this question give all answers to $3$ significant figures. The reaction between $\mathrm{NaOH}$ and $\mathrm{HCl}$ can be written as:

$\mathrm{HCl}+\mathrm{NaOH}\to \mathrm{NaCl}+{\mathrm{H}}_2\mathrm{O}$

In this reaction, $15.0 {\mathrm{cm}}^3$ of hydrochloric acid was neutralised by $20.0 {\mathrm{cm}}^3$ of $0.0500 \mathrm{mol} {\mathrm{dm}}^{-3}$ sodium hydroxide. Calculate the volume in ${\mathrm{dm}}^3$ of the alkali.

In this question give all answers to $3$ significant figures. The reaction between $\mathrm{NaOH}$ and $\mathrm{HCl}$ can be written as:

$\mathrm{HCl}+\mathrm{NaOH}\to \mathrm{NaCl}+{\mathrm{H}}_2\mathrm{O}$

In this reaction, $15.0 {\mathrm{cm}}^3$ of hydrochloric acid was neutralised by $20.0 {\mathrm{cm}}^3$ of $0.0500 \mathrm{mol} {\mathrm{dm}}^{-3}$ sodium hydroxide. Calculate the number of moles of alkali.