Comment
I'm going to round the atomic masses of these elements. Every periodic table is different, and they use different numbers. Besides, this is multiple choice, so all you have to do is come close.
Givens
The atomic masses of the elements in the compound are
Cr = 52
Cu = 63.5
O = 16
Atomic Mass 1 mole
2 Cu = 2 * 63.5 = 127
1 Cr = 1 * 52 = 52
O4 = 4 * 16 = 64
Total = 243 grams / 1 mole
Answer
1 mole = 243 grams
0.11 mole = x
1/0.11 = 243 / x Cross multiply
x = 0.11 * 243
x = 26.7
Answer 27 grams or D
