Chemistry Calculations help find the mole ratio!?
2015-05-27 5:50 pm
a student has a sample of the mixed salt PbCO3 X Pb(OH)2. In a mixed salt two compounds are mixed together in one crystal. X represents the mole ratio between the two compounds, and is usually a small whole number. The Student heats the sample with sulfuric acid which causes the salt to react completely, producing PbSO4, CO2, and H2O as the products. if 2.280 g of PbSO4 and 0.1101 g of CO2 are produced in the reaction, what is the value of X for this particular mixed salt?
回答 (1)
2015-05-27 11:36 pm
PbCO3 + H2SO4 → PbSO4 + CO2 + H2O [balanced as written]
(0.1101 g CO2) / (44.00964 g CO2/mol) x (1 mol PbCO3 / 1 mol CO2) = 0.00250172 mol PbCO3
(0.1101 g CO2) / (44.00964 g CO2/mol) x (1 mol PbSO4 / 1 mol CO2) x (303.2626 g PbSO4/mol) =
0.75868 g PbSO4 from PbCO3
(2.280 g PbSO4 total) - (0.75868 g PbSO4 from PbCO3) = 1.5213 g PbSO4 from Pb(OH)2
Pb(OH)2 + H2SO4 → PbSO4 + 2 H2O
(1.5213 g PbSO4) / (303.2626 g PbSO4/mol) x (1 mol Pb(OH)2 / 1 mol PbSO4) = 0.0050164 mol Pb(OH)2
(0.0050164 mol Pb(OH)2) / (0.00250172 mol PbCO3) = 2.005
Since the question guarantees that this ratio will be a small integer, X must be 2.
(0.1101 g CO2) / (44.00964 g CO2/mol) x (1 mol PbCO3 / 1 mol CO2) = 0.00250172 mol PbCO3
(0.1101 g CO2) / (44.00964 g CO2/mol) x (1 mol PbSO4 / 1 mol CO2) x (303.2626 g PbSO4/mol) =
0.75868 g PbSO4 from PbCO3
(2.280 g PbSO4 total) - (0.75868 g PbSO4 from PbCO3) = 1.5213 g PbSO4 from Pb(OH)2
Pb(OH)2 + H2SO4 → PbSO4 + 2 H2O
(1.5213 g PbSO4) / (303.2626 g PbSO4/mol) x (1 mol Pb(OH)2 / 1 mol PbSO4) = 0.0050164 mol Pb(OH)2
(0.0050164 mol Pb(OH)2) / (0.00250172 mol PbCO3) = 2.005
Since the question guarantees that this ratio will be a small integer, X must be 2.
收錄日期: 2021-05-01 20:34:32
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20150527095057AAvHasP