将2.3g钠投入水中得100ml溶液,在烧杯中滴入3滴酚酞,然后加入50ml某浓度的H2SO4溶液,溶液刚好变成无色.1

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  • 2.3g钠物质的量为2.3g/23g/mol=0.1mol,2Na+2H2O=2NaOH+H2↑,所以产生0.05mol氢气体积0.05molx22.4L/mol=1.12L,得到0.1mol氢氧化钠,2NaOH+H2SO4=Na2SO4+2H2O,所以需要硫酸0.05mol而用了50ml所以c=n/v=0.05mol/0.05L=1mol/L