Question

将Na2CO3和NaHCO3混合物19g,充分加热后,收集到CO2有1.12L（标准状况）,冷却后将剩余固体溶于300m

Answer 1

n(CO2) = 1.12/22.4 = 0.05mol

2NaHCO3 ==△== Na2CO3 + H2O + CO2↑

2 1

n 0.05mol

2/n = 1/0.05mol

n = 0.1mol

m(NaHCO3) = 84*0.1 = 8.4g

m(Na2CO3) = 19 - 8.4 = 10.6g

(2)

原混合物中n(Na2CO3) = 10.6/106 = 0.1mol

0.1mol NaHCO3分解后又生成0.1/2 = 0.05mol Na2CO3

所以所配制的溶液的物质的量浓度 = (0.1+0.05)/0.3 = 0.5mol/L