实验室用密度为1.84g/cm3.质量分数为98%的浓硫酸和蒸馏水,配制500g质量分数为20%的稀硫酸.需要用多少mL的浓硫酸( ) A.100mL ,54.35mL B.250mL,54.35mL c.100mL,55.5mL D.250mL ,55.5mL 要讲解.

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实验室用密度为1.84g/cm3.质量分数为98%的浓硫酸和蒸馏水,配制500g质量分数为20%的稀硫酸.需要用多少mL的浓硫酸( ) A.100mL ,54.35mL B.250mL,54.35mL c.100mL,55.5mL D.250mL ,55.5mL 要讲解.
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实验室用密度为1.84g/cm3.质量分数为98%的浓硫酸和蒸馏水,配制500g质量分数为20%的稀硫酸.需要用多少mL的浓硫酸( ) A.100mL ,54.35mL B.250mL,54.35mL c.100mL,55.5mL D.250mL ,55.5mL 要讲解.
实验室用密度为1.84g/cm3.质量分数为98%的浓硫酸和蒸馏水,配制500g质量分数为20%的稀硫酸.需要用多少mL的浓硫酸( ) A.100mL ,54.35mL B.250mL,54.35mL c.100mL,55.5mL D.250mL ,55.5mL 要讲解.

实验室用密度为1.84g/cm3.质量分数为98%的浓硫酸和蒸馏水,配制500g质量分数为20%的稀硫酸.需要用多少mL的浓硫酸( ) A.100mL ,54.35mL B.250mL,54.35mL c.100mL,55.5mL D.250mL ,55.5mL 要讲解.
解设需用98%浓硫酸的质量为 x,则:
x * 98%=500g * 20%(根据配制前后,溶质的质量不变)
x=102.04g
又因为 浓硫酸体积v =质量/密度=102.04g/1.84(g/cm3)=55.5cm3=55.5mL.