Crude oil is separated into useful fractions using fractional distillation.
The table below shows the percentages of crude oil fractions from different oil wells.
| Fraction | Percentage of fraction in Well P | Percentage of fraction in Well Q | Percentage of fraction in Well R |
|---|---|---|---|
| Refinery gas | 3 | 5 | 8 |
| Gasoline | 7 | 12 | 22 |
| Kerosene | 10 | 14 | 18 |
| Diesel | 15 | 18 | 16 |
| Fuel oil | 25 | 28 | 26 |
| Residue | 40 | 23 | 10 |
A barrel of crude oil from Well Q has a mass of 145 kg145\text{ kg}145 kg. Calculate the mass of kerosone in this barrel.
Alkanes have the general formula CnH2n+2\text{C}_n\text{H}_{2n+2}CnH2n+2. Write the formula of octadecane, the alkane with 18 carbon atoms.
A sample of dodecane, C12H26\text{C}_{12}\text{H}_{26}C12H26, was cracked. One molecule of dodecane produced two molecules of propene, C3H6\text{C}_3\text{H}_6C3H6, and one molecule of product YYY.
C12H26→2C3H6+product Y \text{C}_{12}\text{H}_{26} \rightarrow 2\text{C}_3\text{H}_6 + \text{product } Y C12H26→2C3H6+product YWrite the chemical formula for product YYY.
83 exam-style questions on OCR GCSE Chemistry Organic chemistry. Each one has a worked solution and a mark scheme showing where the marks go.