Photo AI
6 (a) Explain one advantage of using biodiesel made from plant oils compared with using fossil diesel made from crude oil - AQA - GCSE Chemistry - Question 6 - 2017 - Paper 1
Question 6
6 (a) Explain one advantage of using biodiesel made from plant oils compared with using fossil diesel made from crude oil. _________________________________________... show full transcript
Worked Solution & Example Answer:6 (a) Explain one advantage of using biodiesel made from plant oils compared with using fossil diesel made from crude oil - AQA - GCSE Chemistry - Question 6 - 2017 - Paper 1
Step 1
Explain one advantage of using biodiesel made from plant oils compared with using fossil diesel made from crude oil.
Answer
One advantage of using biodiesel is that it is carbon neutral. This means that the carbon dioxide released when biodiesel is burned is equivalent to the carbon dioxide absorbed by the plants used to produce it during photosynthesis. This provides a more sustainable and environmentally friendly alternative compared to fossil diesel.
Step 2
Explain how an emulsion of water and oil is formed.
Answer
An emulsion is formed when an emulsifier is added to a mixture of water and oil. The hydrophilic (water-attracting) end of the emulsifier dissolves in the water, while the hydrophobic (oil-attracting) end dissolves in the oil. This creates a stable mixture where small droplets of one liquid are suspended in the other, resulting in a consistent texture.
Step 3
Step 4
Describe and explain what happens to plant oils when they react with hydrogen in the presence of a nickel catalyst at about 60 °C.
Answer
When plant oils react with hydrogen in the presence of a nickel catalyst at about 60 °C, the hydrogen adds across the carbon-carbon double bonds in the unsaturated oils. This process, known as hydrogenation, opens up the double bonds, transforming unsaturated fats into saturated fats, which typically have higher melting points and can change the texture of the oils.