14.2g(NH4)2C2O4•xH2O中含有1.204×1023个NH4+,该物质的摩尔质量是_,x的值是_.

问题描述:

14.2g(NH42C2O4•xH2O中含有1.204×1023个NH4+,该物质的摩尔质量是______,x的值是______.

14.2g(NH42C2O4•xH2O中含有1.204×1023个NH4+
NH4+的物质的量=

1.204×1023
6.02×1023mol−1
=0.2mol,
则(NH42C2O4•xH2O的物质的量=
0.2mol
2
=0.1mol,
故(NH42C2O4•xH2O的摩尔质量=
14.2g
0.1mol
=142g/mol,
所以18x+18×2+24+64=142,解得x=1,
故答案为:142g/mol;1.