## Chemistry: Stoichiometry

Chemistry: Stoichiometry

Please help me to solve these problems. Ignore question 1 and 2. Also number 22-26 are repeated 3 times. I wil post the problems in the additional files. Also please

type down how to solve the problems.

Chemistry:  Stoichiometry  1. How many moles of O2 should be supplied to burn 1 mol of C3H8 (propane) molecules in a camping stove?
2. How many moles of O2 molecules should be supplied to burn 1 mol of CH4 molecules in a domestic furnace?
3. Sodium thiosulfate (Na2S2O3), photographer’s “hypo” reacts with unexposed silver bromide in the film emulsion to form sodium bromide and a compound of formula Na5

[Ag(S2O3) 3].  How many moles of Na2S2O3 formula units are needed to make 0.10 mol of AgBr soluble?
4. Calculate the mass of alumina (Al2O3) produced when 100 g of aluminum burns in oxygen.
5. “Slaked lime,” Ca(OH) 2, is formed from “quick-lime” (CaO) by adding water.  What mass of water is needed to convert 10 kg of quicklime to slaked lime?  What mass

of slaked lime is produced?
6. Camels store the fat tristearin (C57H110O6) in  the hump.  As well as being a source of energy, the fat is a source of water, because when it is used the reaction

2 C57H110O6(s)   +   163 O2(g)   Æ                                       114 CO2(g)   +   110 H2O(l)    takes place.  What mass of water is available from 1.0 kg

of fat?
7. The compound diborane (B2H6) was at one  time considered for use as a rocket fuel.  How many grams of liquid oxygen would a rocket have to carry to burn 10 kg of

diborane completely?  (The products of the combustion are B2O3 and H2O.)
8. Given the balanced chemical equation
Br2   +   2 NaI   Æ   2 NaBr   +   I2  How many moles of sodium bromide (NaBr) could be produced from 0.172 mol of bromine (Br2)?
9. How many formula units of calcium oxide (CaO) can be produced from 4.9 x 105 molecules of oxygen gas (O2) that react with calcium (Ca) according to this balanced

chemical equation?  2 Ca(s)   +   O2 (g)   Æ   2 CaO(s)  10. Aluminum metal (Al) reacts with sulfur (S) to produce aluminum sulfide (Al2S3) according to this balanced

chemical equation: 2 Al(s)   +   3 S(s)   Æ   Al2S3(s)  How many atoms of aluminum will react completely with 1.33 x 1024 atoms of sulfur?
Name _____________________________ Hr ___
LIMITING  REAGENTS
11. What is the maximum mass of methane (CH4)  that can be burned if only 1.0 g of oxygen is available?
12. What is the maximum mass of glucose  (C6H12O6) that can be burned in 10 g of oxygen?
13.  The solid fuel in the booster stage of the space shuttle is a mixture of ammonium perchlorate  and aluminum powder, which react as follows:     6 NH4ClO4(s)

+   10 Al(s)   Æ   5 Al2O3(s)   +                                     3 N2(g)   +   6 HCl(g)   +  9 H2O(g)  What mass of aluminum should be mixed with 5.0  x 103 kg

of ammonium perchlorate, if the reaction  proceeds as stated?
14. A solution containing 5.0 g of silver nitrate was mixed with another containing 5.0 g of potassium  chloride.  Which was the limiting reagent for the

precipitation of silver chloride?
15. Given the balanced chemical equation            2 Ag   +   I2   Æ   2 AgI  How many atoms of silver metal (Ag) are required to react completely with 531.8 g of

iodine (I2) to produce silver iodide (AgI)?
16. The theoretical yield of ammonia in an industrial synthesis was 550 tons, but only 480 tons was  obtained.  What was the percentage yield of the  reaction?
17. Calculate the volume occupied by 16.3 moles of nitrogen gas (N2) at STP.  18. How many moles of fluorine gas (F2) are  contained in 0.269 dm3 container at STP?
19. Assuming that the gases are all at STP, find the  volume of nitrogen dioxide gas (NO2) that could be produced from 71.11 dm3 of nitrogen gas (N2) according to this

balanced chemical equation.  N2(g)   +   2 O2(g)   Æ   2 NO2(g)  20. How many moles of oxygen (O2) would be  needed to produce 79.60 moles of sulfur trioxide (SO3)

according to the following balanced chemical equation?
2 SO2   +   O2   Æ   2 SO3
21.  How many grams of water will be produced from 50 g hydrogen reacting with 50 g oxygen?
Think Critically
22.  The reaction of 1 mol of C to form carbon monoxide in the reaction 2 C(s)   +   O2(g)  Æ   2 CO(g)   releases 113 kJ of heat.  How much heat will be released by

the combustion of 100 g of C according the the above information?
23. According to the balanced chemical equation; how many atoms of silver will be produced from combining 100 g of copper with 200 g of silver nitrate?  Cu(s)  +  2

AgNO3(aq)   Æ   Cu(NO3) 2(aq)   +  2 Ag(s)  24. According to the balanced chemical equation;  how many moles of SO2(g) will be produced when 1.5 x 108 molecules of

zinc sulfide react with 1000 dm3 of oxygen gas?  Assume a 75% yield.  2 ZnS(s)   +   3 O2 (g)   Æ   2 ZnO(s)   +  2 SO2(g)  25. I need to produce 500 g of lithium

oxide(Li2O) a) how many grams of Lithium AND b) how many liters of oxygen do I need
The balanced equation is:   Li   +   O2   Æ   LiO2
26. How many grams of water will be produce from 50 g hydrogen reacting with 50 g oxygen?
Think Critically:
22.  The reaction of 1 mol of C to form carbon monoxide in the reaction 2 C(s)   +   O2(g)  Æ   2 CO(g)   releases 113 kJ of heat.  How much heat will be released by

the combustion of 100 g of C according the the above information?
23.  According to the balanced chemical equation; how many atoms of silver will be produced from combining 100 g of copper with 200 g of silver nitrate?  Cu(s)  +  2

AgNO3(aq)   Æ   Cu(NO3) 2(aq)   +  2 Ag(s)  24. According to the balanced chemical equation;  how many moles of SO2(g) will be produced when 1.5 x 108 molecules of

zinc sulfide react with 1000 dm3 of oxygen gas?  Assume a 75% yield.  2 ZnS(s)   +   3 O2 (g)   Æ   2 ZnO(s)   +  2 SO2(g)  25. I need to produce 500 g of lithium

oxide(Li2O) a. how many grams of Lithium AND b. how many liters of oxygen do I need
The balanced equation is:   Li   +   O2   Æ   LiO2
26.  How many grams of water will be produced from 50 g hydrogen reacting with 50 g oxygen?
Think Critically:
22.  The reaction of 1 mol of C to form carbon monoxide in the reaction 2 C(s)   +   O2(g)  Æ   2 CO(g)   releases 113 kJ of heat.  How much heat will be released by

the combustion of 100 g of C according the the above information?
23.  According to the balanced chemical equation; how many atoms of silver will be produced from combining 100 g of copper with 200 g of silver nitrate?  Cu(s)  +  2

AgNO3(aq)   Æ   Cu(NO3) 2(aq)   +  2 Ag(s)  24. According to the balanced chemical equation;  how many moles of SO2(g) will be produced when 1.5 x 108 molecules of

zinc sulfide react with 1000 dm3 of oxygen gas?  Assume a 75% yield.  2 ZnS(s)   +   3 O2 (g)   Æ   2 ZnO(s)   +  2 SO2(g)  25. I need to produce 500 g of lithium

oxide(Li2O) a. how many grams of Lithium AND b. how many liters of oxygen do I need
The balanced equation is:   Li   +   O2   Æ   LiO2
26.  How many grams of water will be produced from 50 g hydrogen reacting with 50 g oxygen?
Think Critically:
22.  The reaction of 1 mol of C to form carbon monoxide in the reaction 2 C(s)   +   O2(g)  Æ   2 CO(g)   releases 113 kJ of heat.  How much heat will be released by

the combustion of 100 g of C according the the above information?
23.  According to the balanced chemical equation; how many atoms of silver will be produced from combining 100 g of copper with 200 g of silver nitrate?  Cu(s)  +  2

AgNO3(aq)   Æ   Cu(NO3) 2(aq)   +  2 Ag(s)  24. According to the balanced chemical equation;  how many moles of SO2(g) will be produced when 1.5 x 108 molecules of

zinc sulfide react with 1000 dm3 of oxygen gas?  Assume a 75% yield.  2 ZnS(s)   +   3 O2 (g)   Æ   2 ZnO(s)   +  2 SO2(g)  25. I need to produce 500 g of lithium

oxide(Li2O) a. how many grams of Lithium AND b. how many liters of oxygen do I need
The balanced equation is:   Li   +   O2   Æ   LiO2
26. How many grams of water will be produced from 50 g hydrogen reacting with 50 g oxygen?
Think Critically
22.  The reaction of 1 mol of C to form carbon monoxide in the reaction 2 C(s)   +   O2(g)  Æ   2 CO(g)   releases 113 kJ of heat.  How much heat will be released by

the combustion of 100 g of C according the the above information?
23. According to the balanced chemical equation; how many atoms of silver will be produced from combining 100 g of copper with 200 g of silver nitrate?  Cu(s)  +  2

AgNO3(aq)   Æ   Cu(NO3) 2(aq)   +  2 Ag(s)
24. According to the balanced chemical equation;  how many moles of SO2(g) will be produced when 1.5 x 108 molecules of zinc sulfide react with 1000 dm3 of oxygen gas?

Assume a 75% yield.  2 ZnS(s)   +   3 O2 (g)   Æ   2 ZnO(s)   +  2 SO2(g)
25. I need to produce 500 g of lithium oxide(Li2O) a) how many grams of Lithium AND b) how many liters of oxygen do I need
The balanced equation is:   Li   +   O2   Æ   LiO2
26.  A tin ore contains 3.5% SnO2.  How much tin is produced by reducing 2.0 kg of the ore with carbon? SnO2   +   C   Æ   Sn  +   CO2
27.  If 36.5 g of HCl and 73 g of Zn are put together:
2 HCl   +   Zn   Æ   ZnCl2   +   H2  a. Determine which reactant is the limiting reactant, b. Find the mass of ZnCl2 formed, c. Find the volume of H2 (@ STP) formed,

d. Determine which reactant is in excess and by how much.
28. Many plants synthesize glucose by photosynthesis as follows:   CO2(g)  +  H2O(l)  +  energy  Æ  C6H12O6(s)  +  O2(g)  a. Write a balanced equation for this

process, b. How many molecules of water are needed to make one molecule of glucose? c. How many liters of oxygen (@STP) are given off when 2.50 mol of glucose is

synthesized? d. How many moles of CO2 are needed for a plant to make 2.50 mole of glucose? e. How many carbon atoms are used to produce 2.50 mole of glucose? f. How

many dm3 of oxygen gas are produced from 9.32 dm3 of CO2 (all @ STP)?
29. Assume that the human body requires daily energy that comes from metabolizing 816 g of sucrose, C12H22O11, using the following reaction: C12H22O11(s)   +   12 O2

(g)   Æ   12 CO2(g)   +                 11 H2O(l)   +    energy  How many dm3 of pure oxygen (@ STP) is consumed by a human being in 24 hours?
30. A student has a mixture of KClO3, K2CO3, and KCl.  She heats 50 g of the mixture and determines that 5 g O2 and 7 g CO2 are produced by these reactions:  2 KClO3

(s)   Æ   2 KCl(s)   +   3 O2(g) K2CO3(s)   Æ   K2O(s)   +  CO2(g)  KCl is not affected by the heat.  What is the percent composition of the original mixture?

ANSWERS:   1.  5 mol O2   2.  2 mol O2   3.  0.3 mol Na2S2O3   4. 189 g Al2O3   5.  3214 g H2O and 13.2 kg slaked lime [Ca(OH) 2]   6.  998 g water   7.  34,783 g O2

8.  0.344 mol NaBr   9.  9.8 x 105 molecules CaO 10.  8.9 x 1023 atoms Al 11.  0.25 g CH4 12.  9.375 g C6H12O6 13.  1915 kg Al 14.  silver nitrate 15.  2.5 x 1024

atoms Ag 16.  87.3 % yield 17.  365 L N2 18.  0.012 mol F2 19.  142 L NO2 20.  39.8 mol O2 21.  56.25 g H2O 22.  942,000 J 23.  7.1 x 1023 atoms Ag 24.  1.9 x 10-16mol

(NOT 2.5 x 10-16mol:  75% Yield) 25a.        g Li       b.      L O2 26.  27a.                b.               c.              d.   28a.        b. 6  c. 336    d. 15

e. 9 x 1024     f.  9.32 29.  641 L O2 30.  15.2 g KCl 