A student estimated the temperature of a Bunsen burner flame using the apparatus shown - Edexcel - A-Level Physics - Question 1 - 2023 - Paper 6

The recording of the results has several issues:

1. Inconsistent Data: Not all mass values were recorded under the same conditions, which leads to variability in results.
2. Significant Figures: The recorded temperature increases lack a consistent number of significant figures.
3. No Units for Temperature Increase: The results do not include the units for temperature increase, making it unclear what the values represent.

One variable that should be controlled is the time for heating the screw. This ensures that every trial has the same heating duration, providing consistent results.

To find the temperature of the Bunsen burner flame, we can use the formula for energy exchange: $E = mc heta$

Where:

• $E$ is the energy,
• $m$ is the mass,
• $c$ is the specific heat capacity,
• $heta$ is the temperature change.

From the given data:

• For water, let’s take the mass ($m_{water}$) as 9.9g: $E_{water} = m_{water} imes c_{water} imes heta_{water}$ $E_{water} = 9.9 imes 10^{-3} imes 4180 imes 62 = 2570 J$

• For the screw ($m_{screw} = 4.11g$): $E_{screw} = m_{screw} imes c_{screw} imes heta_{screw}$ $E_{screw} = 4.11 imes 10^{-3} imes 420 imes heta_{screw}$

Setting these equal, we have: $2570 = 4.11 imes 10^{-3} imes 420 imes heta_{screw}$ Calculating, we find: heta_{screw} = rac{2570}{4.11 imes 420} ext{ which yields } heta_{screw} ext{ approximately equal to } 1490°C

Thus, if the initial temperature of the water is around 20°C, the actual temperature of the Bunsen burner flame would be: $ext{Bunsen Flame Temp} = heta_{screw} + 20 = 1490 + 20 = 1510°C$

Therefore, the flame temperature can be rounded to approximately 1500°C above the initial temperature of the water.