Ecosystems

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Question 31
Medium

Gardeners are investigating two different methods of aerobic composting to see which method decomposes organic plant waste faster: a Standard Bin and an Insulated Hotbin.

They start with two identical piles of green waste and record the mass of the waste at the start and after 30 days.

Table 18.2: Mass of organic material during composting

Composting methodMass at start (kg\text{kg}kg)Mass after 30 days (kg\text{kg}kg)
Standard Bin180018001800115011501150
Insulated Hotbin180018001800820820820

During aerobic decomposition, gases such as carbon dioxide are released, which accounts for most of the decrease in mass.

a.

Calculate the percentage decrease in the mass of the organic material in the Standard Bin. Give your answer to 2 significant figures.

[2]
b.

Calculate the percentage decrease in the mass of the organic material in the Insulated Hotbin. Give your answer to 2 significant figures.

[2]
c.

Suggest why insulation in the Hotbin leads to a higher rate of decomposition.

[2]

Ecosystems Questions

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