Question

12.5g of zinc tioxocarbonate (iv), znco3 were heated very strongly to a constant mass and the residue heated with excess hydrochloric acid Hcl calculate the mass of zinc that would be obtained

Answer 1

I need the assignment right now pls

Answer 2

ZnCO3 ==> ZnO + CO2, then
ZnO + 2HCl ==> ZnCl2 + H2O

mols Zn = grams/atomic mass = 12.5/65.4 = about 0.2 but that's just an estimate. You need to recalculate all of these numbers for a better answer to this question. Looking at the equation 1 mol ZnCO3 produces 1 mol ZnO and 1 mol ZnO produces 1 mol ZnCl2; therefore, 1 mol Zn will produce 1 mol ZnCl2. Thus you will obtain approximately 0.2 mols ZnCl2.
Then grams ZnCl2 = mols ZnCl2 x molar mass ZnCl2 = ?.

12.5/125*136
0.1*136=13.6 answer

Answer 3

Hope that helped! Your welcome! :-)

Answer 4

I should point out that the problem asks for the amount of Zn from these reactions; however, Zn is not produced anywhere. Second, the response by Helper gives the grams of ZnCl2 produced, which is not the question, but undoubtedly is what the student intended to ask and 13.6 g ZnCl2 is correct. Finally, the statement "Thus you will obtain approximately 0.2 mols ZnCl2 is not correct because you didn't start with 0.2 mol ZnCO3.