The alkanes quiz

1. What is our main source of hydrocarbon molecules?

a) Natural gas
b) Crude oil
c) Coal
d) Limestone

2. Crude oil is formed from the remains of:

a) Dinosaurs
c) Ancient trees
c) Microscopic sea creatures (plankton)
d) Ancient marine plants

3. Why did the remains of the plankton not decay when they died?

a) They were frozen
b) They were exposed to oxygen
c) They were buried and lacked enough oxygen for decay to occur
d) They were buried with too much oxygen present

4. are molecules which consist of the two elements carbon and and they are found in crude oil.

5. Over millions of years what cause the remains of plankton to turn into crude oil?

a) Cool temperatures
b) Exposure to sunlight, oxygen and water
c) Evaporation of water and exposure to sunlight
d) Increased pressure and temperature

6. Why is crude oil described as a finite resource??

a) It is found everywhere
b) It forms slowly and is used up quickly
c) It renews every year
d) It can easily be produced by scientists in the lab

7. Which of the following is true of alkanes?

a) They are saturated and contain only single bonds
b) They are unsaturated hydrocarbons
c) They contain carbon, hydrogen and oxygen atoms
d) They contain double bonds between the carbon atoms

8. What is the general formula for the alkanes?

a) C_nH_2n
b) C_nH_2n+2
c) C_nH_2n-2
d) C_nH_n+2

9. What is the correct formula for butane?

a) C₃H₈
b) C₂H₆
c) C₅H₁₀
d) C₄H₁₀

10. Which name prefix matches an alkane with 5 carbon atoms?

a) Pent-
b) Hex-
c) Hept-
d) Oct-

11. The alkanes can form a:

a) Mixed compound series
b) A homologous series
c) A polymer chain
d) A polypeptide chain

12. What is true about the members of a homologous series?

a) Their chemical properties vary widely
b) Their physical properties change randomly
c) They have similar chemical properties and show gradual changes in their physical properties
d) They have different general formulas

13. Which statement below best describes methane?

a) It is a hydrocarbon with 3 carbon atoms
b) It contains a carbon oxygen double bond
c) It is an alkene
d) It is the first member of the alkane homologous series

14. Which of the following statements is true?

a) Larger alkane molecules are more flammable than smaller ones
b) Viscosity decreases as the alkane molecues get larger
c) Smaller alkanes burn with cleaner flames
d) Larger alkane molecules are more volatile than smaller ones

15. When a clean white evaporating basin was placed in a flame it was quickly covered in a black powder. What does this show?

a) Complete combustion
b) The alkane is very volatile
c) Incomplete combustion and soot production
d) The burning substance is not a hydrocarbon