Based on the balanced chemical equation shown below, determine the mass percent of Fe3+ in a 0.6450 g sample of iron ore, if 22.40 mL of a 0.1000 M stannous chloride, SnCl2(aq), solution is required to completely react with the Fe3+ present in the ore sample. The chemical equation for the reaction is
2 Fe3+ (aq) + Sn2+ (aq) →2Fe2+ (aq) + Snº+(aq).
O 19.40%
O 6.196%
O 38.79%
O 9.697%

38.9%

Explanation:

below, determine the mass percent of Fe3+ in a 0.6450 g sample of iron ore, if 22.40 mL of a 0.1000 M stannous chloride, SnCl2(aq), solution is required to completely react with the Fe3+ present in the ore sample. The chemical equation for the reaction is

2 Fe3+ (aq) + Sn2+ (aq) →2Fe2+ (aq) + Snº+(aq).

O 19.40%

O 6.196%

O 38.79%

O 9.697%

 2 Fe3+ (aq) + Sn2+ (aq) →2Fe2+ (aq) + Snº+(aq).ole of Sn2+

for every mole of Sn2+, tere are 2 moles of Fe3+

so there are 0.00224 X 2= 0.00448 moles Fe3+

iron atomic mass is 56

56 X 0.00448 = 0.251 gm Fe3+

so the mass % of the Fe3+ in the 0.645 gm iron ore sample is

(0.251/0.645) X 100 = 38.9%

you need to take a look at the periodic system in order to sort these elements into pairs that would most likely exhibit similar chemical properties. first, you need to find elements that are found in the same group (groups are vertical in the periodic system), and then to see whether they have the same valence number. if they meet these criteria, they will have similar properties.

the first pair: ne (neon) and kr (krypton), are noble gases found in group 8

the second pair: li (lithium) and k (potassium), found in group 1

the third pair: s (sulfur) and te (tellurium), found in group 6