Question 1(multiple choice worth 4 points)
(05.04 mc)
in an experiment, zinc chlorate decomposed according to the following chemical equation.
zn(clo3)2 → zncl2 + o2
(molar mass of zn(clo3)2 = 232.29 g/mol; zncl2 = 136.286 g/mol; o2 = 31.998 g/mol)
if the mass of zinc chlorate was 150 grams, which of the following calculations can be used to determine the mass of oxygen gas formed?
(150 × 1 × 232.29) ÷ (31.998 × 3) grams
(150 × 3 × 232.29) ÷ (31.998 × 1) grams
(150 × 1 × 31.998) ÷ (232.29 × 3) grams
(150 × 3 × 31.998) ÷ (232.29 × 1) grams
question 2(multiple choice worth 4 points)
(05.04 lc)
how many moles of sulfuric acid (h2so4) are needed to react completely with 6.8 moles of lithium hydroxide (lioh)?
2lioh + h2so4 → li2so4 + 2h2o
3.4 mol h2so4
6.8 mol h2so4
10.2 mol h2so4
13.6 mol h2so4
question 3(multiple choice worth 4 points)
(05.04 mc)
what mass of h2 is needed to react with 8.75 g of o2 according to the following equation: o2(g) + h2(g) → h2o(g)?
0.547 g h2
1.10 g h2
4.38 g h2
17.5 g h2
question 4(multiple choice worth 4 points)
(05.04 mc)
read the following chemical equation.
fe + o2 → fe2o3
which of the following fractions can be used for the mole ratio to determine the mass of fe from a known mass of fe2o3?
four over two
three over two
two over three
two over four
question 5(multiple choice worth 4 points)
(05.04 lc)
which of the following is a valid mole ratio from the balanced equation 2fe2o3 + 3c → 4fe + 3co2?
four moles of c over three moles of f e
two moles of f e two o three over four moles of c
three moles of c over four moles of c o two
four moles of f e over three moles of c o two