Answer:
3. 76 g/ml^3
Explanation:
We are given the mass of the metal pellets which is 33.4 grams. To calculate the density of the metal, we need to divide the mass by the volume. The volume of the metal is not directly given so we need to find it ourselves. The water was initially 12.7 ml and then it rose to 21.6 ml after placing the metal pellets. This indicate that the volume of the metal pellets is 8.9 ml.

We can now use the density formula.



Moles of Zn: 26 / 65 = 0.4
Moles of S: 12.8 / 32 = 0.4
Molar ratio of Zn : S = 1 : 1
Empircal formula: ZnS
The answer is C
Copper choruses purpose is its used as a catalyst for organic and inorganic reactions , mordant for dyeing and printing textiles, pigment for glass and ceramics, wood preservative, disinfectant, insecticide, fungicide, and herbicide. (Not sure if you want the actual purpose of water or not)