(I know this is late so hopefully other people find it helpful)
<u>Answer</u>: Solid Cu
Since this is a <u>voltaic cell</u>:
<u>Copper</u> is the cathode, therefore having a positive charge.
<u>Zinc</u> is the anode, therefore having a negative charge.
(Also, I took the exam and it's correct; good luck everyone!)
Calcium carbonate has the formula: CaCO3
From the periodic table:
mass of calcium = 40 grams
mass of carbon = 12 grams
mass of oxygen = 16 grams
Therefore,
molar mass of CaCO3 = 40 + 12 + 3(16) = 100 grams
molar mass of carbonate = 12 + 3(16) = 60 grams
One mole of calcium carbonate contains one mole of carbonate. Therefore, 100 grams of CaCO3 contains 60 grams of CO3.
If the 0.5376 grams of the unknown substance is CaCO3, then the amount of carbonate will be:
amount of carbonate = (0.5376*60) / 100 = 0.32256 grams
Based on the above calculations, the sample is not CaCO3
Effects of changes in volume in a reversible reaction in a chemical equilibrium can be predicted using Le Chatelier's Principle. I think this might be the answer, I hope it helps.