calculation

1. CALCULATION:<br />Experiment A :<br />Excess zinc granules react with 50 cm3 sulphuric acid 0.5 mol dm-3 at room condition.<br />Experiment B :<br />Excess zinc granules react with 50 cm3 hydrochloric acid 0.5 mol dm-3 at room condition<br />Question:<br />(i)Compare the gas collected between Experiment A and Experiment B.<br />Sample Answer:<br />Experiment A : <br />REACTANTPRODUCTchemical equationZnH2SO4ZnSO4H2Mole ratio1111n,molexcess=50 ×0.51000 =0.025=0.025Volume of gas,dm3---=0.025 ×24=0.6<br />Experiment B: <br />REACTANTPRODUCTchemical equationZn2HClZnCl2H2Mole ratio1211n,molexcess=50 ×0.51000 =0.025=0.0252=0.0125Volume of gas,dm3---=0.0125 ×24=0.3<br />Volume of gas in Experiment A is 0.6 dm3 higher than Experiment B is 0.3 dm3<br />(ii) Calculate the gas collected when the Experiment A repeated and changed the Excess zinc granules to excess zinc powder.<br />Sample Answer:<br />Volume of gas in Experiment A is 0.6 dm3. Volume of gas given off equal because size of reactant , not effect to amount of gas collected.<br />(iii)Calculate the gas collected when Experiment A and Experiment B are repeated and changed excess zinc granules to 2 gram zinc granules.<br />Sample Answer:<br />REACTANTPRODUCTchemical equationZnH2SO4ZnSO4H2Mole ratio1111n,mol=265=0.03≡excess=50 ×0.51000 =0.025=0.025Volume of gas,dm3---=0.025 ×24=0.6<br />Volume of gas in Experiment A is 0.6 dm3 <br />(iv)Calculate the gas collected when experiment (iii) repeated and used the 1.0 mol dm-3 concentration of both acid<br />Sample Answer:<br />REACTANTPRODUCTchemical equationZnH2SO4ZnSO4H2Mole ratio1111n,mol=265=0.03=50 ×1.01000 =0.05≡excess=0.03Volume of gas,dm3---=0.03 ×24=0.72<br />