Ⅰ.
818O的原子结构示意图为:
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/2fdda3cc7cd98d10af13f080223fb80e7aec90b8?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
;
818O的质子数位8,质量数位18,中子数为18-8=10;N=nN
A=
N
A,所以分子数之比与摩尔质量之比成反比,等质量的
18O
2和
16O
2含有的分子数之比为:32g/mol:36g/mol=8:9,
故答案为:
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/2fdda3cc7cd98d10af13f080223fb80e7aec90b8?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
;10; 8:9;
Ⅱ.向FeCl
3溶液中加入a g的铜粉,搅拌使之全部溶解,反应为:Cu+2Fe
3+=2Fe
2++Cu
2+,溶液中一定含有阳离子为Fe
2+、Cu
2+,铁离子可能为全部反应,所以可能含有阳离子Fe
3+;再向其中加入 b g铁粉,充分反应后过滤得滤渣c g,可能发生反应的离子方程式:2Fe
3++Fe=3Fe
2+、Fe+Cu
2+=Fe
2++Cu,
故答案为:Fe
2+、Cu
2+;Fe
3+;2Fe
3++Fe=3Fe
2+、Fe+Cu
2+=Fe
2++Cu.