If 32.5g sodium sulfide is added to copper (II) acetate (as much as needed to react), how many grams each product do you have?

Question

Chemistry question. Can you set up the equation?

Answer 1

I agree with the other respondents, but if you don't mind, I like to set it up as follows:

 

32.5 g  Na2S     +            Cu(Ac)2     ------>      2                NaAc    +                 CuS

 

but that needs fixing because coefficients are never in grams:

 

32.5/78  Na2S    +           Cu(Ac)2     ------>      2                NaAc    +                 CuS

 

I just felt like students kept things straight more simply.  Anyway, now just proceed as Jon and Chris showed:

 

0.4164  Na2S     + 0.4164 Cu(Ac)2     ------>    2 (0.4164) NaAc    +    (0.4164) CuS

Answer 2

Acetate is CH₃C00^-, so copper (II) acetate is Cu(CH₃C00)₂.

 

Sodium sulfide is Na₂S.

 

Both of the initial reactants are soluble in water, so they will react in solution, and copper (II) sulfide, which is not soluble in water, will precipitate out, and sodium acetate will remain.

 

The equation is:

 

Na₂S + Cu(CH₃C00)₂ ---> 2 CH₃C00Na + CuS

 

To find out how much of each product there is, we have to figure out how much we are starting with.

 

The atomic mass of sodium is 23.0 and the atomic mass of sulfur is 32.1.  (Since we're given the amount of sodium sulfide to 3 significant figures, we stick with 3 figures for the atomic masses.)  So the molecular mass of Na₂S is 2*23.0 + 32.1 = 78.1.

 

So 32.5 g of sodium sulfide is 32.5 / 78.1 = .416 moles

 

The reaction will result in 2 * .416 = .832 moles of sodium acetate and .416 moles of copper sulfide.

 

Now that you know how many moles of each product will result, just figure out their molecular mass to determine how many grams of each there will be.  I'll leave that to you.

 

 

 

Answer 3

Sodium sulfide (32.5g) added to Copper (II) acetate (excess)

 

Na₂S + Cu(C₂H₃O₂)₂ → 2NaC₂H₃O₂ + CuS

 

From here it is a simple stoichiometry problem:

 

Sodium acetate:

32.5 g Na₂S * (1 mol Na₂S / 78.045 g NaS₂) * (2mol NaC₂H₃O₂ / 1 mol Na₂S) * ( 82.034 g NaC₂H₃O₂ / 1 mol NaC₂H₃O₂)

= 68.3 g NaC₂H₃O₂

 

Copper (II) sulfide:
32.5 g Na₂S * (1 mol Na₂S / 78.045 g NaS₂) * (1mol CuS / 1 mol Na₂S) * ( 95.61 g CuS / 1 mol CuS)
= 39.8 g CuS