Past exam questions Flashcards
What are the advantages and disadvantages for using poly(ethene) bags. (6mark)
Advantages: - Bags can be burnt for energy - Can be reused and/or recycled - Can be made so they are biodegradable Disadvantages: - Take a long time to degrade - Shortage of landfill sites - Bags made from crude oil which is a non renewable source.
Buildings made from limestone are affected by the products from burning fossil fuels containing sulfur.
Explain why. (2marks)
- Sulfur reacts with Oxygen to make sulfur dioxide.
- Sulfur dioxide then dissolves into rain water causing acid rain ( which erodes limestone)
When a mixture of limestone and clay is heated in a rotary kiln cement is produced. Burning a mixture of methane and air heats the kiln. Clay does not decompose in the kiln.
(1a) Carbon dioxide is one of the main gases coming out of the kiln, what is the other main gas?(2marks)
(1b) Co2 is one of the main gases coming out of the kiln. Explain why.(2marks)
(1a)Nitrogen(1mark)- main gas in air(1mark)
(1b) - co2 produced from decomposing caco3.
- methane reacts with oxygen from air.
Olive oil is hardened to make margarine.
Describe the reaction and condition needed to harden the vegetable oil. (3marks)
- Hydrogenated
- using nickel catalyst
- under the temp of 60 degrees Celsius
balance the following equation:
C⁶ H¹⁴ —> _______ + ________
(2marks)
- C²H⁴ + C⁴H¹⁰
Scientist believe that the outer layer of the earth is cracked into a number of large pieces.
Whats the name of these large pieces. (1mark)
- Tectonic plates
What is the chemical formula and displayed structure of
propene?(2marks)
-C³H⁶ H H | | - C=C- C - H | | | H H H
Why is neon in the same group as helium? (1mark)
Helium- 2 and Neon - 2,8
Because they have a stable arrangement of electrons.
ignore Full outer shell of electrons
What are alkanes? (2marks)
Hydrocarbons that contain singles bonds.
Between the hydrogen and carbon.
Why does iceland have volcanoes?(1mark)
Where tectonic plates collide.
Suggest a reason why scientists can not predict earth quakes. (1mark)
Not all tremors indicate volcanoes will erupt.
Describe how volcanic activity led to the formation of the Oceans. (2marks)
Water vapour released by volcanoes
which soon condensed into oceans
Describe how activity within the earth results in earthquakes. (3 marks)
Earthquakes caused by sudden movements in earth plates.
Due to convection currents In earths mantle
Which is due to radioactive decay.
A student said that hardening would make olive oil healthier.
Is he correct?
Explain your answer in terms of what happens in the hardening process. (2marks)
No because hardening olive oil would cause double bonds to break into single bonds.
so more saturated fats,
