4 grams of H2O produces 0.67g of HF. What is the % yield?

Question

CH3COF+ H2O —> CH3COOH + HF

1. 91%
2. 111%
3. 656%
4. 15%
5. 22%

Answer 1

Hello, Caitlyn,

We will assume that there is a surplus of CH₃COF and that all of the water is consumed. 4 grams of water is 4g/18g/mole, or 0.222 moles H₂O. The balanced equation shows molar ratio of water to HF of 1. We should get one mole of HF for every one mole H₂O. 0.222 moles H₂O should produce 0.222 moles HF. Multiply that by the molar mass of HF to get grams. (0.222 moles HF)(19.99 g/mole HF) = 4.44 grams HF. We actually got 0.67 grams, so that is a (0.67/4.44) or 15.1% yield. Wow. - I hope I'm wrong.

Bob