A chemist decomposes samples of several compounds. The masses of their constituent elements are listed. Calculate the chemical formula for each compound

We need to know the molar masses of every element in the given compound first.

a) 58.69 g = 1 mole of Ni

Therefore, 1.245 g = 0.0212 moles

126.9 g = 1 mole of I

Therefore, 5.381 g = 0.0424 moles

Ratio of Ni : I = 0.0212 / 0.0424 = 1 : 2

Therefore, empirical formula is NiI2

b) 137.327g = 1 mole of Ba

2.677 g = 0.0195 moles

79.90 g = 1 mole of Br

3.115 g = 0.0390 moles

Ratio of Ba : Br = 0.0195 / 0.0390 = 1 : 2

Therefore, the empirical formula is BaBr2.

c) 9.012 g = 1 mole of Be

2.128 g = 0.236 moles

32.065 g = 1 mole of S

7.557 g = 0.236 moles

15.999 g = 1 mole of O

15.107 g = 0.944 moles

Therefore, ratio of Be : S : O = 0.236 : 0.236 : 0.944 = 1 : 1 : 4

Therefore, the empirical formula is BeSO4.

idk i’m struggling too