Percentage yield and reversible reactions 0.0 / 5 ? ScienceyieldGCSEAQA Created by: nimrahali12Created on: 11-02-17 15:27 Percentage yield compares? actual and predicted yeild 1 of 26 What is a yield? The amount of product you get 2 of 26 The more reactants you start with , the higher? the actual yield will be 3 of 26 But the percentage yeild doesn't depend on the amount of reactants you start with , its the? the amount of reactants you start with-its the percentage 4 of 26 The predicted yield of a reaction can be calculated with? from the balanced reaction equation 5 of 26 What is the percentage formula? percentage yield=actual yield divided by predicted yield time 100 6 of 26 Percentage yield is always between? 0-100% 7 of 26 the 100% yield means? that you got all the product you expected to get 8 of 26 The 0% means? no reactants were converted into product (no product made) 9 of 26 Yields are always less than? 100% 10 of 26 Even though no atoms are gained or lost in reactions , in real life you never get? 100% yield 11 of 26 Some product or reactants always get lost and that goes for? big industrials processes as well as school lab experiments 12 of 26 What are the following reasons for this? 1) reversible reactions 2)filter liquid 3) does not go exactly to plan 13 of 26 1)what is a reversible reaction? is one where the procuts of the reaction can themselves react to produce original reactants 14 of 26 For example? ammonium chloride------ ammonia + hydrogen chloride 15 of 26 This means? that the reactants will never be completely converted to products because the reaction goes both ways. 16 of 26 Some of the products are always? reacting together to change back to the original reactants 17 of 26 This will mean a lower? yield 18 of 26 2)When you filter a liquid to remove solid particles , you nearly always lose? abit of liquid or solid 19 of 26 So some of the products may be lost when? its separated from the reaction mixture 20 of 26 3)Things don't always go exactly to plan, sometimes there can be other unexpected reactions happening which? use up the reactants 21 of 26 This means? there is not that as much reactants to make the product you want 22 of 26 Product yield is important for? sustainable development 23 of 26 What is sustainable development? is about making sure that we don't use resources faster than they can be replaced-there needs to be a future generation too 24 of 26 For example? using as little energy as possible to create the highest product yield as possible this means that resources are saved 25 of 26 A low yeild means? wasted chemicals- not very sustainable 26 of 26
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