1. What happens to the boiling point of alkanes as the size of the molecule increases?
2. Which of the following alkanes has the lowest boiling point?
3. Which of the following alkanes is a liquid at room temperature?
4. is how easily a substance flows, honey for example is a viscous substance while petrol has a low and flows easily.
5. What happens to the viscosity as the chain length of the alkane molecule increases?
6. Why do larger alkane molecules have higher boiling points than smaller alkane molecules?
7. What does the term volatile mean in chemistry?
8. What causes a substance to be more volatile?
a) Large molecules and strong intermolecular bonding b) Small molecules and weak intermolecular bonding c) The presence of carbon carbon double bonds d) High viscosity
9. Which alkane below is the most volatile?
a) Methane b) Propane c) Butane d) Decane
10. Which of the substances below is the most flammable?
a) Pentane b) Ethane c) Heptane d) Octane
11. What is meant by the flash point of a liquid?
a) The temperature where it begins to boil b) The temperature where it has maximum viscosity c) The temperature at which its vapour can ignite briefly d) The temperature where complete combustion starts
12. What happens to the flash point of an alkane molecule as the molecule gets larger?
a) It increases b) It decreases c) It stays the same d) It fluctuates randomly
13. What burns when a liquid alkane in a beaker is ignited in the lab?
a) The carbon atoms in the alkane only b) The vapour above the liquid c) The liquid alkane d) The solid form of the alkane
14. Which of the following statements is true?
a) Large alkane molecules are more flammable than smaller ones b) Viscosity decreases as molecules get larger c) Smaller alkane molecules burn with cleaner flames d) Large alkane molecules are more volatile than smaller ones
15. A clean white evaporating basin was placed in a flame and it quickly turned black, what does this show?
a) Complete combustion of the fuel being burned b) The burning fuel is very volatile c) Incomplete combustion of the fuel and soot production d) The fuel releases lots of energy when it is being burned
