chemistry specification part 4

Question 1

are neutralisation reaction exo or endo?

Answer 1

acid and a base react to make salt and water and most neutralisation reactions are exothermic however the neutralisation between ethanoic acid and sodium carbonate is endothermic

Question 2

are displacement reaction exo or endo

Answer 2

more reactive element replaces a less reactive element in a compound. These reactions include a release of energy-exothermic

Question 3

are precipitation reactions exo or endo

Answer 3

exothermic. e.g lead nitrate and potassium iodide forming a lead iodide precipitate would result in an increase in the temperature of the surroundings

Question 4

what is the formula for overall energy change

Answer 4

energy required to break bond — energy required to form bond

Question 5

what are hydrocarbons

Answer 5

compounds which contain only carbon and hydrogen

Question 6

what is crude oil and its structure

Answer 6

-a complex mixture of lots of different hydrocarbons. They are arranged in either chains or rings and are most alkanes.(hydrocarbons with the formula CnH2n+2
-finite resource from fossils

Question 7

how is crude oil important

Answer 7

our main source of hydrocarbons and is used as raw materials (feedstock) to create useful substances used in the petrochemical industry

Question 8

what are gases used for

Answer 8

domestic cooking and heating

Question 9

what is kerosene used for

Answer 9

fuel for aircraft

Question 10

what is fuel oil used for

Answer 10

large ships and some power stations