题目内容
向盛有25mL0.2mol/L的Na2CO3溶液的试管中通过一支插到试管底部的长滴管,徐徐注入0.1mol/L盐酸75mL,在标况下,产生CO2气体体积为( )
A.28mL | B.42mL | C.56mL | D.84mL |
n(Na2CO3)=0.025L×0.2mol/L=0.005mol,n(HCl)=0.075L×0.1mol/L=0.0075mol,
将稀盐酸缓缓滴到Na2CO3溶液中,先发生Na2CO3+HCl═NaCl+NaHCO3,反应消耗0.005molHCl,剩余0.0025molHCl,
盐酸过量时在发生NaHCO3+HCl═NaCl+CO2↑+H2O,则生成气体0.0025mol×22.4L/mol=0.056L=56ml,
故选C.
将稀盐酸缓缓滴到Na2CO3溶液中,先发生Na2CO3+HCl═NaCl+NaHCO3,反应消耗0.005molHCl,剩余0.0025molHCl,
盐酸过量时在发生NaHCO3+HCl═NaCl+CO2↑+H2O,则生成气体0.0025mol×22.4L/mol=0.056L=56ml,
故选C.
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