Explaination needed for Stoichiometric problem and is Al salt colorless?

[yeahyeah<3]

Homework Statement

The mass of element Q found in 1.00 mole of each of four different compounds is 38.0 grams, 57.0 grams, 76.0 grams, and 114 grams, respectively. A possible atomic weight of Q is

a) 12.7
b 19.0
c 27.5
d 38.0

A solution is known to contain an inorganic salt of one of the following

elements. The solution is colorless. The solution contains a salt of:

(A) Cu (B) Mn (C) Fe (D) Ni (E) AL

I do not know the answer to this. I know Cu is blue, Mn is pale pink, Ni is green, Co is redish and Al is silver white.

Homework Equations

The Attempt at a Solution

I know the answer is b. 19.0 grams. However, I'm not 100% sure how to get that answer. I know that it's the only one when the compound masses are divided by it you receive whole numbers. Is that how i was supposed to do the problem? That doesn't make sense to me because other elements could have been in the compound..


THANK YOU :)

 

[mgb_phys]

The Attempt at a Solution

I know the answer is b. 19.0 grams. However, I'm not 100% sure how to get that answer. I know that it's the only one when the compound masses are divided by it you receive whole numbers. Is that how i was supposed to do the problem? That doesn't make sense to me because other elements could have been in the compound..

Note that it says the mass of element Q in each sample - not the total mass of the sample!