Question

1) All of the following are oxidation-reduction reactions except
(a) 2Al(s) + Fe2O3(s) ¨A12O3(s) + 2Fe(s)
(b) (NH4)2Cr2O7(s) ¨ Cr2O3(s) + N2(g) + H2O(1)
(c) Cu(s) + 2H2SO4(aq) ¨ CuSO4(aq) + SO2(g) + 2H2O(1)
(d) Hg(NO3)2 + 4KI ¨ K2HgI4(aq) +
2 KNO3(aq)
(e) 2Na(s) + 2H2O(1) ¨ 2NaOH(aq) +
H2(g)



2) 13.00 mL of 0.52 M barium chloride is added to 8.00 mL of 0.68 M sodium sulfate in a beaker.
Identify the limiting reagent and its concentration?
BaCl2(aq) + Na2SO4(aq) ---> BaSO4 (s) + 2NaCl(aq)
(a) BaCl2 is the limiting reagent at a concentration of 6.76 x 10-3 mol
(b) BaCl2 is the limiting reagent at a concentration of 5.44 x 10-3 mol
(c) Na2SO4 is the limiting reagent at a concentration of 5.44 x 10-3 mol
(d) Na2SO4 is the limiting reagent at a concentration of 6.76 x 10-3 mol
(e) Neither as both have the same concentration


iii) Dilute acetic acid is added to solid nickel(II) carbonate.

i am not sure with the question , if u explain how to work out

Answer 1

Determine moles BaCl2 = M x L.
Determine moles Na2SO4 = M x L.

If moles are different e can't be right. Determine the lesser quantity, that will be the limiting reagent. I should point out here that none of the answers, technically, is correct. All of the answers cite moles while concn is moles/L. I supppose you are to go with the answer that is correct in moles.

iii. I don't know what the question is for this one but NiCO3 will dissolve in dilute acetic acid if it isn't too dilute.

Answer 2

it is to work to find the net ionic equation for question iii