Calculations Based on Equations Intermediate 2 Chemistry ? ?

Balanced Equations Allow us to calculate the quantity of product from a particular quantity of reactant C 2 H 4 + H 2 O C 2 H 6 O 1 mole From the balanced equation, 1 mole of ethene reacts with 1 mole of water, to produce 1 mole of ethanol.

Example 1 Suppose you want to work out how much ethanol can be produced by the hydration of 10 g ethene… C 2 H 4 + H 2 O C 2 H 6 O 1. Balanced equation 1 mole 2. Moles ratio So… 28 g46 g 3. Gram formula masses And therefore… 1 g 4. What 1 would give Which means… 46 g 28 g 5. What you actually have But we have… 10 g 10 x 46 g 28 g = 16.4 g

Example 2 Try the following problem: What would be the yield of ammonia obtained in the reaction between 3 kg of hydrogen with excess nitrogen? 1. Balanced equation 2. Moles ratio 3. Gram formula masses 4. What 1 would give 5. What you actually have N 2 + H 2 NH 3 32 = 17 kg 3 moles2 moles So… 3 x 2 g 2 x 17 g 6 g34 g And therefore… 1 g 34 g 6 Which means… 34 g 6 x 3 3 kg But we have…