用20gNaOH配成500ml溶液,取出1mL用水稀释到100mL,所得溶液中溶质的c是?,含Na+?克

问题描述:

用20gNaOH配成500ml溶液,取出1mL用水稀释到100mL,所得溶液中溶质的c是?,含Na+?克

c = (20/40)/0.5/100
m(Na) = 20*23/40/500

c = (1/500 *0.5 )/0.1
m(Na) = 20*(1/500)

20/40==0.5mol
0.5/0.5=1mol/L
取出1mL用水稀释到100mL,所得溶液中溶质的c是
1*0.001/0.1==0.01mol/L
0.01*0.1*23==0.023g