Figure 2 shows one type of calorimeter - AQA - A-Level Biology - Question 3 - 2020 - Paper 1

The insulation of the calorimeter reduces heat loss to the environment. This keeps the heat generated from the biomass combustion focused on increasing the water temperature, providing a more accurate measure of total heat energy released.

The heat energy absorbed by the water can be calculated using the formula:

$Q = m imes c imes riangle T$

Where:

• $Q$ is the heat energy (in Joules),
• $m$ is the mass of water (100 cm³, which is equivalent to 100 g),
• $c$ is the specific heat capacity of water (4.18 J/g°C),
• $riangle T$ is the temperature change (15.7 °C).

Substituting the values:

$Q = 100 imes 4.18 imes 15.7 = 6576.6 ext{ J}$

To convert this to kJ, we divide by 1000:

$Q_{kJ} = \frac{6576.6}{1000} = 6.5766 ext{ kJ}$

The heat energy released per gram of biomass is then:

$\frac{6.5766 ext{ kJ}}{2 ext{ g}} = 3.2883 ext{ kJ/g}$. So the final answer is approximately 3.29 kJ/g.

1. Much of the light is reflected by the surfaces of the leaves, preventing it from being absorbed for photosynthesis.

2. The light may have wavelengths that are not suitable for chlorophyll absorption, meaning it cannot be used in the photosynthesis process.