Question 1
How much carbon monoxide is required to reduce 2.00 metric tons (2000 kg) of iron ore if the ore is 5.03% iron?
Fe
2O
3(s) + 3 CO(g) → 2 Fe(l) + 3 CO
2(g)
◦ 151 kg
◦ 75.7 kg
◦ 25.2 kg
◦ 40.7 kg
◦ 50.5 kg
Question 2
If an aqueous solution is prepared by dissolving 1.6 mol Na
2CrO
4 in 1.0 L of a buffer at pH 8.24, what will be [Cr
2O
72-] in the solution? The resultant equilibria are:
HCrO
4-(aq)
H
+(aq) + CrO
42-(aq)
Ka = 3.2 × 10
-7
2 HCrO
4-(aq)
Cr
2O
72-(aq)+ H
2O(l)
K = 33
◦ 9.9 × 10
-5 M
◦ 2.9 × 10
-28 M
◦ 8.9 × 10
-9 M
◦ 8.6 × 10
2 M
◦ 2.8 × 10
-2 M