Question

An unknown metal M reacts with S to form a compound with a formula M2S3. If 3.12g of m reacts with exactly 2.88g of sulfur, what are the names of metal M and compound M2S3?

Answer 1

Given all these,

let M = atomic weight of M

THen, it becomes 2M + 3S ? M2S3

Since molar ratio is 2:3

2M g of M + 3* 32.056g of S

2M/(3*32.056) g will react with 1.000 g of S

Then, you get [2M/(3*32.056)]*2.88 g of M will react with 2.88 g of S

Given this equals 3.12 g

==> 3.12 = [2M/(3*32.056)]*2.88 = 0.05990M

M= 52.1 g; using at wt of S = 32.0 gives M = 52.0 so it is chromium At Wt = 51.996

Then, name of this compound will be chromium(III) sulfide