Photo AI
9 (a) When water boils and turns into steam, there are changes in the arrangement of particles and the density - Edexcel - GCSE Physics - Question 9 - 2022 - Paper 1
Question 9
9 (a) When water boils and turns into steam, there are changes in the arrangement of particles and the density. Which of these shows the changes? A. bigger than in ... show full transcript
Worked Solution & Example Answer:9 (a) When water boils and turns into steam, there are changes in the arrangement of particles and the density - Edexcel - GCSE Physics - Question 9 - 2022 - Paper 1
Step 1
When water boils and turns into steam, there are changes in the arrangement of particles and the density. Which of these shows the changes?
Answer
The correct answer is B: bigger than in water and less than water. As water boils, the space between the particles in steam increases, leading to a decrease in density compared to liquid water.
Step 2
Figure 21 shows some water in a measuring cylinder and a lump of iron. Calculate the density of the lump of iron.
Answer
To calculate the density of the lump of iron, we first determine the volume of the iron: 530 cm³ (final water level) - 490 cm³ (initial water level) = 40 cm³.
Using the formula for density:
density = \frac{mass}{volume}
We know the density of iron is 7.9 g/cm³:
7.9 = \frac{mass}{40}
Rearranging gives:
mass = 7.9 \times 40 = 316 g.
Thus, to 2 significant figures, the mass is 320 g.
Step 3
Explain why the method used in part (b) cannot be used to determine the mass of the piece of wood.
Answer
The method from part (b) cannot be used for the wood because wood floats on water, preventing it from being fully submerged. This results in less volume of water being displaced than the volume of the wood, leading to inaccurate volume readings and subsequently, mass calculations.
Step 4
Describe the method the student should use to determine the specific heat capacity of water.
Answer
To determine the specific heat capacity of water, the student should:
- Set up the apparatus: Use a low voltage heater and a beaker filled with a known volume of water.
- Measure initial temperature: Record the initial temperature of the water using a thermometer.
- Add the heater: Submerge the low voltage heater in the water to provide heat.
- Measure final temperature: After heating for a set amount of time, measure the final temperature of the water.
- Record voltage and current: Measure the voltage across the heater and the current passing through it to calculate the power (P = IV).
- Calculate energy supplied: Use the formula: energy supplied = power \times time.
- Use the formula for specific heat capacity: Apply the specific heat formula:
temperature change = \frac{energy}{mass \times specific heat capacity}. 8. Rearrange and solve to find specific heat capacity.
A diagram may help show the arrangement of the apparatus.