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Urea, (NH₂)₂CO, is a fertiliser - OCR Gateway - GCSE Chemistry - Question 12 - 2019 - Paper 2
Question 12
Urea, (NH₂)₂CO, is a fertiliser. A student makes 1 mole of urea from 2 moles of ammonia. What is the mass of urea that the student makes? A 43.0 g B 44.0 g C 58.0... show full transcript
Worked Solution & Example Answer:Urea, (NH₂)₂CO, is a fertiliser - OCR Gateway - GCSE Chemistry - Question 12 - 2019 - Paper 2
Step 1
What is the mass of urea that the student makes?
Answer
To determine the mass of urea produced, we start with the balanced chemical equation for the formation of urea from ammonia:
From the equation, we see that 2 moles of ammonia ( ext{NH}_3) react to produce 1 mole of urea. The molecular mass of urea
is calculated as follows:
- Atomic mass of Nitrogen (N): approximately 14.0 g/mol
- Atomic mass of Hydrogen (H): approximately 1.0 g/mol
- Atomic mass of Carbon (C): approximately 12.0 g/mol
- Atomic mass of Oxygen (O): approximately 16.0 g/mol
The molecular formula for urea is ext{(NH}_2)_2\text{CO}, which gives us:
Since the student produces 1 mole of urea, the mass of urea made is 60.0 g. Therefore, the answer is:
D 60.0 g.