Bethan prepared some ethoxyethane (line 6) by reacting ethanol with concentrated sulfuric acid. She used 69g of ethanol (Mr=46) and obtained a 45% yield of ethoxyethane (Mr=74). Calculate the mass of ethoxyethane obtained.

A Level
  1. Equation from line 6 is: 2 (ethanol) -------> 1 (ethoxyethane)
    2. The ratio of reaction is 2:1. This is the ratio of moles not mass, i.e., 2 moles of ethanol give 1 mole of ethoxyethane.
    3. We need to know how many moles of ethanol are used. Recall the [ Mass = Mr . Mole ] equation * Get 1.5 moles of ethanol
    4. To be consistent with the ratio, we need 0.75 moles of ethoxyethane.
    5. Use [ Mass = Mr . Mole ] to find mass of product. * This will be 55.5 g
    6. Explain that things go wrong in real life experiments and processes and the concept of yield. Bethan has 45% of what the product would be in an ideal world. * Final Solution = 24.98 g

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