Amount of Substance 0.0 / 5 ? ChemistryAmount of SubstanceASAQA Created by: jackjj9Created on: 10-10-16 20:54 What is the ideal gas equation? PV = nRT 1 of 30 What is the equation to work out the number of moles? n = mass / Mr 2 of 30 What is the equation to find concentration? C = n / volume (in decimetres cubed) 3 of 30 What must first be found to calculate reacting masses? The limiting reagent 4 of 30 What is standard temperature? 273K (0C) 5 of 30 What is standard pressure? 100kPa 6 of 30 What volume does 1 mole of gas at rtp occupy? 24dm3 7 of 30 What volume does one mole of any gas at stp occupy? 22.4dm3 8 of 30 As temperature increases, does the volume increase or decrease? Increase 9 of 30 What is the equation for volume of a gas at rtp? V = n * 24 10 of 30 What is the equation for volume of a gas at stp? V = n * 22.4 11 of 30 What is theoretical yield? The maximum amount of product that can be obtained from a reaction, in theory 12 of 30 Give 2 reasons why actual yield never equals theoretical yield? Incomplete reactions/unwanted reactions/escaping gasses 13 of 30 What is a standard solution? A solution whose concentration is very accurately known 14 of 30 What is the required practical of this unit? Titration 15 of 30 What is the amount added from the burette called? The titre 16 of 30 When should you stop repeating a a titration? When concordant results are found 17 of 30 What are concordant results? When 2 results agree to the precision of the apparatus (in the case of a burette, 0.1cm3) 18 of 30 What is the formula for the efficiency of a reaction? (Actual yield / Theoretical yield)*100 19 of 30 What is atom economy? A way of measuring the amount of wasted/lost atoms in a reaction 20 of 30 How can you work out atom economy? (Total Mr of all reactants / Total Mr of all products) *100 21 of 30 What is empirical formula? The simplest ratio of all the elements in a compound 22 of 30 How do you calculate empirical formula from masses? Assume 100g = 100% and work out number of moles. Divide through by smallest number. Get ratio. 23 of 30 A compound is found to contain 50.05 % sulfur and 49.95 % oxygen. Empirical formula? SO2 24 of 30 How do you calculate the molecular formula from an empirical formula? Divide the mass given in question by the Mr of the empirical formula and multiply each element by this 25 of 30 What result should be used in titration calculations? The average between all the concordant results while ignoring the rough result 26 of 30 What indicator should be used in a titration? Phenolphthalein 27 of 30 What colour is phenolphthalein in an alkali? Pink 28 of 30 What colour is phenolphthalein in an acid? Colourless 29 of 30 In what molar ratio does a monoprotic acid react? 1:1 30 of 30

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