1. (a) A student had solutions of four different foods labelled W, X, Y and Z. Each solution was tested for starch and protein. The colour of the solutions after the tests are shown in Figure 1. solution colour after testing for starch colour after testing for protein W orange purple X blue/black purple Y blue/black blue Z orange blue (i) Which solution contains starch but not protein? A solution W B solution X C solution Y D solution Z (b) Figure 2 shows a calorimeter. Describe how this calorimeter can be used to find the energy content of 10g of food.

GCSE Edexcel Biology Core Practical: Food Tests: 1. (a) A student had solutions o

1. (a) A student had solutions of four different foods labelled W, X, Y and Z - Edexcel - GCSE Biology - Question 1 - 2019 - Paper 1

Question 1

1. (a) A student had solutions of four different foods labelled W, X, Y and Z. Each solution was tested for starch and protein. The colour of the solutions after the... show full transcript

Worked Solution & Example Answer:1. (a) A student had solutions of four different foods labelled W, X, Y and Z - Edexcel - GCSE Biology - Question 1 - 2019 - Paper 1

Step 1

Which solution contains starch but not protein?

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Answer

To determine which solution contains starch but not protein, we analyze the colors indicated in Figure 1:

Solution W: Orange indicates the presence of starch and purple indicates the presence of protein.
Solution X: Blue/black indicates starch and purple indicates protein.
Solution Y: Blue/black indicates starch and blue indicates no protein.
Solution Z: Orange indicates starch and blue indicates no protein.

From this analysis, solution Y is the only one that contains starch (blue/black) and does not contain protein (blue), making the correct answer C solution Y.

Step 2

Describe how this calorimeter can be used to find the energy content of 10g of food.

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Answer

To find the energy content of 10g of food using the calorimeter:

Preparation of the Sample: We start by placing a known amount (10g) of food in the combustion chamber of the calorimeter.
Water Measurement: Ensure the calorimeter contains a measured volume of water (100 cm³) in the chamber beneath the combustion chamber.
Ignition: Ignite the food sample in the combustion chamber. As the food burns, it releases heat.
Temperature Change Measurement: The heat generated from the burning food will raise the temperature of the water. Use a thermometer to record the initial and final temperatures of the water.
Calculating Energy Content: The energy released by the food can be calculated using the formula:

$ext{Energy (J)} = ext{mass of water (kg)} imes ext{specific heat capacity of water (J/kg°C)} imes ext{temperature change (°C)}$

By substituting the values into the formula, you can find the energy content of the 10g food sample.

1. (a) A student had solutions of four different foods labelled W, X, Y and Z - Edexcel - GCSE Biology - Question 1 - 2019 - Paper 1

Worked Solution & Example Answer:1. (a) A student had solutions of four different foods labelled W, X, Y and Z - Edexcel - GCSE Biology - Question 1 - 2019 - Paper 1

Which solution contains starch but not protein?

Describe how this calorimeter can be used to find the energy content of 10g of food.

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