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Combined Practice
Write and balance the reaction, answer the ÿTuestions that follow. Use dimensional analysis, show units, and show work. You wilf need
to do your work on another sheet of paper.
Carbon disulfide is an important industrial solvent. It is prepared by the reaction of coke (a solid carbon source made
.
from coal) with sulfur dioxide.
5C(s) + 2SO2(g) ÿ CS2(I) + 4CO(g)
a. How many moles of CS2 form when 2.7 mol C reacts? O,5ÿ,'ÿ,1Cÿ;z
b. • How many moles of carbon are-needed to react with 5.44 mol SO2? 13, ÿ, m o I C.
c. How many moles of carbon monoxide form at the same time that 0.246 mol CS2 forms? O, 98LI'ÿolCo
d. How many mol SO2 are required to make118 mol CS2? 23ÿ,,,,ÿo1.ÿOz
.
Iron(Ill) oxide c&n be reduced with carbon monoxide according to the following equation.
Fe203(s) + 3 CO(g) --+ 2 Fe(s) + 3 CO2(g)
A 16.2 L sample of CO(g) at STP is combined with 15.39 g of Fe203(si.
a.
b.
C.
d.
.
How many moles of CO(g) are available for the reaction? O, "7 2. ÿ t'ÿo] CO
What is the limiting reactant for the reaction? Justify your answer with calculations. ÿe2. 03
How many moles of Fe(s) are formed in the reaction? O, Ict3 tool l'Z'e
How many moles of excess reactant are unreacted or left Over? C)o H 2o ÿ ÿol C O
Answer the following questions about BeC204(s) and its hydrate.
a. Calculate the mass percent of carbon in the hydrated form of the solid that has the formula BeC204• 3 H2
b.. When heated to 220.°C, BeC204• 3 H20(s) dehydrates completely as represented below.
BeC204.3 H20(s) --, BeC204 (s) + 3 H20(g)
If 3.21 g of BeC204• 3 H20(s) is heated to 220.°C, calculate the mass of BeC204 (s) formed.
,
Az0benzene, C12H10N2, is an important intermediate in the manufacture of dyes. It can be prepared by the reaction
between nitrobenzene,CeHsNO2, and thiethylene glycol, 06H1404, in the presence of zinc and potassium hydroxide:
2CeHsNO2 + 406H1404 -)" C12HioN2 + 4C6H1204 + 4H20
a. What is the theoretical yield of azobenzene when 115g of nitrobenzeneand 327 g of t.hiethylene glycol are
allowed to react? ÿ. I ÿ ÿzobe4zeae
(. hÿ-b-obe4zÿ.,,e is L-P-.)
b. If the reaction yields 55g of azobenzene, what is the percent yield of azobenzene?
.
How many grams of butane (C4H10) must be burned in an excess of 02 to produce ;I 5.0g of CO2? /i/, e//9 CV/'ÿlo
,
How many liters of 02 are needed to react completely with IO.0L of H2S at STP according to the unbalanced reaction:
H2S(g) + O2(g)-) SO2(g) + H20(g)
.
/ÿ, O L Oz.
Solid Lithium nitride reacts with water to form ammonia gas and aqueous lithium hydroxide.
Lÿ'ÿ +3]-12_O--ÿ NI43 + 3L',014
a) What mass of water is needed to react with 32.9g Li3N? ÿ'I, 2c3 ÿz.O
b) When the above reaction takes place, how many molecules of NH3 are produced? .ÿoÿ/I ÿ/10;l:ÿP10]e'eÿJ-eÿ/k,] ÿj
c) Calculate the number of grams of Li3N that must be added to an excess of water to produce 15.0L NH3 at STP?
3,25
,
Nitric acid and zinc react to form zinc nitrate, ammonium nitrate and water, ÿ '
a) How many atoms of zinc react with 1.49 g nitric acid? S, "7 i X I 0" I ¢_ÿe,ÿ ÿ G
b) Calculate the number of grams of zinc that must react with an excess of nitric acid to form 29.1 g ammonium
nitrate, q S e 2. ÿ Z
9. Heating an ore of antimony (Sb2S3) in the presence of iron give the element antimony and iron(ll) sulfide.
Sb2S3(s) + 3Fe(s) -) 2Sb(s) + 3FeS(s)
When 15.0g Sb2S3 reacts with an excess of Fe, 9.84 g Sb is produced. What is the percent yield of this reaction?
qi, %
10. Magnesium oxide reacts with gaseous phosphorus pentachloride to form solid magnesium chloride and solid
diphosphorus pentoxide as products. Write a balanced equation for the reaction. Assuming an excess of MgO(s) and
complete reaction, what mass of PCIÿ is required to produce 4.50 kg of diphosphorus pentoxide?
4z'-Pos e 5t%cl , ? os
1s,2 % ocJs
11. Ethylene, C2H4, burns in air according to the following equation: C2H4(g) + 302(g) "-) 2C02(g) + 2H20(/)
How many liters of carbon dioxide, measured at STP, will be formed when a mixture of2.93 g of ethylene and 4.29 g
of oxygen is ignited assuming that the above reaction is the only one to occur?
2.0 L doz
12. If the reaction below proceeds with a 96.8% yield, how many kilograms of CaSO4 are formed when 5.24 kg SO2
reacts with an excess of CaCO3 and 02?
2CaCO3(s) + 2SO2(g) + O2(g) --) 2CaSO4(s) + 2CO2(g)
IO, q KB CaSou.
13. What mass of AgBr(s) is formed when a solution containing 3.45g of KBr is mixed with a solution containing 7.28g of
14. A 5,00 X 102g sample-of AI2(SO4)3 is reacted with 450g of Ca(OH)2.
a. What is the limi&ing reagent in this reaction? /ÿ12 ÿ'-ÿLIÿ3
b. How many moles of the excess reagent are unreacted? ÿo -1 ÿo[ ÿ l.oÿl)ÿ.
gÿ c eÿ5
15. Methanol (CHaOH) is used in the production of many chemicals. Methanol is made by reacting carbon monoxide and
hydrogen at high temperature and pressure.
CO(g) + 2H2(g) -) CHBOH(g)
a) How many moles of each reactant are needed to produce 3.60 x 102 g CH3OH? 11,3ÿo[ C O 4" 2.2..'------£ tool Pr2:
b) Calculate how manymolecules of each reactant needed to produce.4.00 mol CH3OH? el, ql]/IO}ÿlM°/t't',-I-'-ÿ {'O
c) How many grams of hydrogen are necessary to react with 2.85 mol CO?
II,%B H o.
16. Some over4he-counter antacids contain aluminum hydroxide, whereas others contain calcium carbonate. If a tablet
contains 750 mg of AI(OH)3, and another contains 750 mg of CaCO3, which consumes the greater mass.of HCI?