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2 (a) A separating funnel is shown - Edexcel - GCSE Chemistry - Question 2 - 2013 - Paper 1
Question 2
2 (a) A separating funnel is shown. The separating funnel can be used to separate two immiscible liquids, such as oil and water. Describe how you would use a separa... show full transcript
Worked Solution & Example Answer:2 (a) A separating funnel is shown - Edexcel - GCSE Chemistry - Question 2 - 2013 - Paper 1
Step 1
Describe how you would use a separating funnel to separate two immiscible liquids.
Answer
To separate the two immiscible liquids using a separating funnel, follow these steps:
- Allow the layers of liquid to form by letting the mixture settle.
- Place the separating funnel securely on a stand, ensuring it is stable.
- Open the tap at the bottom of the funnel to let the lower layer (e.g., water) run out into a separate container. Make sure this layer is fully drained.
- Once the bottom layer is completely removed, close the tap, and then pour out the remaining upper layer (e.g., oil) from the top.
Step 2
Use the results of the chromatography experiment to describe the colours present in the brown food colouring.
Answer
In the chromatography experiment, the brown food colouring showed two distinct colours:
- Green
- Red This indicates that the brown food colouring is a mixture of these two colours.
Step 3
Explain what happens when each solution is tested in the circuit shown.
Answer
When testing the two solutions in the circuit:
- Sodium chloride solution (an ionic compound) will conduct electricity, leading to the light bulb glowing because it contains ions that can move and carry electric current.
- Sucrose solution (a covalent compound) will not conduct electricity, and the light bulb will not light up, as it lacks free ions necessary for electrical conduction.
Step 4
Calculate the relative formula mass of water, H2O.
Answer
The relative formula mass of water (H2O) can be calculated as follows:
- Hydrogen has a relative atomic mass of 1.0, and there are two hydrogen atoms in water. Therefore, the contribution from hydrogen is:
- Oxygen has a relative atomic mass of 16.0, and there is one oxygen atom in water. Therefore, the contribution from oxygen is:
- Adding these together gives: Hence, the relative formula mass of water, H2O, is 18.0.