Question

将70gNa2O和Na2O2的混合物与98g水充分反应后,所得NaOH溶液溶质质量分数为50%,求混合物中Na2O和Na

Answer 1

设Na2O2为xmol,Na2O为ymol

Na2O-----2NaOH 2Na2O2---4NaOH---O2

1mol 2mol 2mol 4mol 1mol

y 2ymol x 2x 1/2x

m(O2)=1/2x*32g/mol

m液=70g+98g-16x=(168-16x)g

m(NaOH)=（2x＋2y）*40g

m(NaOH）/m液＝50％化简得 62y+78x=70 88x+80y=84

x=0.5=y m(Na2O)=31g m(Na2O2)=39g

2.

设Na2O2为xmol,Na2O为ymol Na2O-----2NaOH 2Na2O2---4NaOH---O2 1mol 2mol 2mol 4mol 1mol y 2ymol x 2x 1/2x m(O2)=1/2x*32g/mol m液=70g+98g-16x=(168-16x)g m(NaOH)=（2x＋2y）*40g m(NaOH）/m液＝50％化简得 62y+78x=70 88x+80y=84 x=0.5=y m(Na2O)=31g m(Na2O2)=39g