For which of the following activities might you want to hire a chemist?
Answer: D. testing a rock sample for gold content
Which of the following procedures involves a physical change in one of the substances?
Answer: C. separating a salt solution by evaporating the water
describes what occurs every time in a given situation
Answer is <span>C: It's appearance changed.</span>
moles Cu produced : 0.002
<h3>Further explanation</h3>
Concentration of copper sulfate (CuSO₄) : 0.319 g/dm³
MW CuSO₄ :

mol CuSO₄ /dm³ :

CuSO₄⇒Cu²⁺ + SO₄²⁻
mol Cu : mol CuSO₄ = 1 : 1 , so mol Cu²⁺=0.002
And the significant amount of volume can be differed by its solitude