As a laid-off worker, it is hard for her father to ______ the family, let alone send his children to key schools. A. bring up B. raise C. support D. supply 答案:C实验室取68g过氧化氢溶液和2g二氧化锰混合制取氧气,待完全反应后,有1.6g氧气生成。求:(1)参加反应的过氧化氢的质量是多少_____________?(2)计算该过氧化氢溶液的溶质质量分数_____________.
3.4g 5%
【解析】(1)设参加反应的过氧化氢的质量是x
2H2O22H2O+O2↑
68 32
x 1.6g
x=3.4g
(2)过氧化氢溶液的溶质质量分数=3.4g÷68g×100%= 5%。
答:(1)参加反应的过氧化氢的质量是3.4g,
(2)该过氧化氢溶液的溶质质量分数为5%