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Flashcards in Alkanes Deck (17):
1

What are Hydrocarbons?

Compounds that contain only hydrogen and carbon atoms

2

What are Alkanes?

Saturated hydrocarbon
Single bonds

3

What is a Homologous series?

Family of organic compounds with same functional group and general formula, similar chemical reactions and similar trends in physical properties

4

Why do Alkanes form a homologous series?

They have the same general formula
Their carbon atoms are joined to each other by single covalent bonds (all alkanes are saturated)

5

What is the general formula for Alkanes?

C H
n 2n+2

6

What are the first 4 alkanes?

Methane (CH4)
Ethane (C2H6)
Propane (C3H8)
Butane (C4H10)

7

What happens as you move down the 4 alkanes?

The number of carbon atoms increases by 1
The number of hydrogen atoms increases by 2

8

How do you model Alkanes?

Using displayed formulae:
Each atom by is chemical symbol (eg. C or H)
Each covalent bond by a straight line

9

How many covalent bonds do Carbon atoms form?

4 covalent bonds

10

How many covalent bonds do Hydrogen atoms form?

1 covalent bond

11

What is the best way to draw the chemical formulae?

Draw the carbon atoms in a line first
Add the correct number of bonds
Add the hydrogen atoms

12

What is the main type of reaction involving Alkanes?

Combustion (reaction when substance burns in oxygen)

13

What happens to Alkanes if there is a plentiful supply of oxygen?

Complete combustion

14

What happens in the Complete combustion of Alkanes?

Carbon atoms are oxidised to carbon dioxide
Hydrogen atoms are oxidised to water

15

What is a word equation to show the complete combustion of Propane?

Propane + Oxygen -> Carbon Dioxide + Water

16

What happens to Alkanes if there is a poor supply of oxygen?

Incomplete combustion

17

What happens in the Incomplete Combustion of Alkanes?

Water is still formed
Carbon is only oxidised to Carbon Monoxide (toxic gas)
Some carbon atoms may not be oxidised at all and released as carbon