Test week 3, chapter 5
What is needed for complete combustion to take place?
A
A good supply of oxygen
B
A very high temperature
C
A fuel with lots of carbon in it A fuel with lots of carbon in it
1 / 13
Lesduur is: 45 minOnderdelen in deze les
What is needed for complete combustion to take place?
A
A good supply of oxygen
B
A very high temperature
C
A fuel with lots of carbon in it A fuel with lots of carbon in it
Slide 1 - Quizvraag
What is meant by the term hydrocarbon?
A
A compound that contains both hydrogen and carbon atoms
B
A compound that only contains hydrogen and carbon atoms
C
A compound that has been obtained from crude oil
Slide 2 - Quizvraag
When a hydrocarbon fuel burns completely, what are the products?
A
Carbon dioxide and water
B
Carbon monoxide and water
C
Carbon dioxide and carbon monoxide
Slide 3 - Quizvraag
What is produced during incomplete combustion that makes the flame sooty
A
Carbon monoxide
B
Carbon
C
Water
Slide 4 - Quizvraag
Which is the most dangerous product of incomplete combustion
A
Carbon monoxide
B
Carbon
C
Water
Slide 5 - Quizvraag
Which of these equations shows complete combustion
A
C3H8 + 5O2 → 3CO2 + 4H2O
B
C3H8 + 3½O2 → 3CO + 4H2O
C
C3H8 + 2O2 → 3C + 4H2O
Slide 6 - Quizvraag
When hydrocarbon fuels burn in a plentiful supply of air they undergo complete combustion,
forming carbon dioxide and water vapour. If the air supply is limited incomplete combustion
occurs and carbon monoxide and carbon may be formed. Describe at least one problem that
can be caused by each of these products of complete and incomplete combustion.
forming carbon dioxide and water vapour. If the air supply is limited incomplete combustion
occurs and carbon monoxide and carbon may be formed. Describe at least one problem that
can be caused by each of these products of complete and incomplete combustion.
Slide 7 - Open vraag
(a) What piece of apparatus is needed to show that a reaction is exothermic? (1)
.....................................................................................................................................
(b) How could you show that the reaction between barium hydroxide solution and dilute hydrochloric
acid is exothermic?
.....................................................................................................................................
(b) How could you show that the reaction between barium hydroxide solution and dilute hydrochloric
acid is exothermic?
Slide 8 - Open vraag
Hydrogen (H2) and chlorine (Cl2) react together to make hydrogen chloride (HCl). This reaction is highly
exothermic. The equation for the reaction can be written as:
H-H + Cl-Cl → H-Cl + H-Cl
(H2 + Cl2 → 2HCl)
What energy transfer takes place when bonds are broken?
What energy transfer takes place when bonds are made?
exothermic. The equation for the reaction can be written as:
H-H + Cl-Cl → H-Cl + H-Cl
(H2 + Cl2 → 2HCl)
What energy transfer takes place when bonds are broken?
What energy transfer takes place when bonds are made?
Slide 9 - Open vraag
A student heated some blue copper sulphate crystals. The crystals turned into white copper
sulphate. The blue copper sulphate had to be continuously heated to change it into white copper
sulphate.
State whether the reaction was exothermic or endothermic. ....................................
Explain your answer.
sulphate. The blue copper sulphate had to be continuously heated to change it into white copper
sulphate.
State whether the reaction was exothermic or endothermic. ....................................
Explain your answer.
Slide 10 - Open vraag
Hydrogen peroxide (H2O2) decomposes very slowly at room temperature.
(i) Complete the balanced chemical equation for this reaction by writing in the formula of
the missing product. 2H2O2 → 2 ............... + O2
(ii) The decomposition is much faster if manganese oxide is mixed with the hydrogen
peroxide. Complete the sentence.Manganese oxide acts as a ................................... for decomposition of hydrogen
peroxide.
(i) Complete the balanced chemical equation for this reaction by writing in the formula of
the missing product. 2H2O2 → 2 ............... + O2
(ii) The decomposition is much faster if manganese oxide is mixed with the hydrogen
peroxide. Complete the sentence.Manganese oxide acts as a ................................... for decomposition of hydrogen
peroxide.
Slide 11 - Open vraag
In an experiment 1g of manganese oxide was mixed with 50 cm3 of hydrogen peroxide solution. Draw a graph of these results. ( Upload a photo of the graph here)
b) How long did it take for the decomposition to stop?
c)Why did the decomposition stop?
b) How long did it take for the decomposition to stop?
c)Why did the decomposition stop?
Slide 12 - Open vraag
In a second experiment water had been added to the hydrogen peroxide solution. Again 50
cm3 of this hydrogen peroxide solution was mixed with 1g of manganese oxide.
(i) For this second experiment, sketch, on the same grid, a graph line you would expect to
get.
(ii) In this second experiment, why would the rate of reaction be different to the first
experiment?
cm3 of this hydrogen peroxide solution was mixed with 1g of manganese oxide.
(i) For this second experiment, sketch, on the same grid, a graph line you would expect to
get.
(ii) In this second experiment, why would the rate of reaction be different to the first
experiment?
