(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 $\text{C}_x\text{H}_y$. $\text{C}_x\text{H}_y + \left(x + \frac{y}{4}\right)\text{O}_2 \rightarrow \dots + \dots$
(c(i))
Which gas is the $30\,\text{cm}^3$ that remained at the end of the experiment?
(c(ii))
Combustion of A gave a gas that reacted with the $\text{KOH(aq)}$. What gas was this?
(c(iii))
What volume of the gas you named in (ii) was formed by the combustion of A?
(c(iv))[4]
What volume of oxygen was consumed in the combustion of A?
(d)[3]
Use the equation in (b) together with your answers to (c)(iii) and (c)(iv) to work out the molecular formula of A. Show all working.