(a)[2]
What does the term molecular formula mean?
(b)[2]
Complete and balance the equation below for the complete combustion of a hydrocarbon with formula $\text{C}_x\text{H}_y$. $\text{C}_x\text{H}_y + (x + \frac{y}{4})\text{O}_2 \rightarrow \ldots + \ldots$
(c(i))[1]
What gas made up the $30\,\text{cm}^3$ that was left at the end of the experiment?
(c(ii))[1]
The combustion of $A$ gave a gas that reacted with the $\text{KOH(aq)}$. What gas is this?
(c(iii))[1]
What volume of the gas identified in (ii) was made by the combustion of $A$?
(c(iv))[1]
What volume of oxygen was consumed in the combustion of $A$?
(d)[3]
Use your equation in (b) together with your answers from (c)(iii) and (c)(iv) to work out the molecular formula of $A$. Show all steps in your working.