问题 填空题

(1)0.3molNH3中所含质子数与______gH2O分子中所含质子数相等.

(2)100mLAl2(SO43溶液中c(SO42-)=0.9mol/L,则n[Al2(SO43]=______.

(3)10mL6mol/L稀硫酸加水稀释到200mL,稀释后c(H+)=______.

(4)已知16gA和20gB恰好完全反应生成0.04molC和31.76gD,则C的摩尔质量为______.

答案

(1)0.3mol NH3含有的质子数的物质的量为0.3mol×(7+3)=3mol,而1molH2O含有(2×1+8)mol=10mol质子,则应有0.3molH2O,质量为m(H2O)=0.3mol×18g/mol=5.4g,

故答案为:5.4;

(2)100mL Al2(SO43溶液中c(SO42-)=0.9mol/L,则n(SO42-)=0.1L×0.9mol/L=0.09mol,

n[Al2(SO43]=

1
3
n(SO42-)=0.03mol,

故答案为:0.03mol;

(3)10mL 6mol/L 稀硫酸加水稀释到200mL,稀释后c(H+)=

0.01L×6mol/L
0.2L
×2=0.6mol/L,

故答案为:0.6mol/L;

(4)16g A和20g B 恰好完全反应生成0.04mol C 和31.76g D,由质量守恒可知m(C)=16g+20g-31.76g=4.24g,

M(C)=

4.24g
0.04mol
=106g/mol,

故答案为:106g/mol.

判断题
判断题