Ch.12 Stoichiometry

how many liters of chlorine gas can be produced when 0.98 L of HCl react with excess O₂ at STP? 4HCl(g) + O₂(g) -> 2Cl₂(g) + 2H₂O(g) a. 0.49 L b. 0.98 L c. 2.0 L d. 3.9 L

a. 0.49 L

which of the following statements is true about the following reaction? 3NaHCO₃(aq) + C₆H₈O₇(aq) -> 3CO₂(g) = 3H₂O(g) + Na₃C₆H₅O₇(aq) a. 1 mole of water is produced for every mole of carbon dioxide produced b. 6.02x10²³ molecules of Na₃C₆H₅O₇(aq) are produced for every mole of NaHCO₃(aq) used c. 54 g of water are produced for every mole of NaHCO₃(aq) produced d. 22.4 L of CO₂(g) are produced for every liter of C₆H₈O₇(aq) reacted

a. 1 mole of water is produced for every mole of carbon dioxide produced

at STP, how many liters of oxygen are required to react completely with 3.6 liters of hydrogen to form water? 2H₂(g) + O₂(g) -> 2H₂O(g) a. 1.8 L b. 3.6 L c. 2.4 L d. 2.0 L

a. 1.8 L

how many liters of hydrogen gas are needed to react with CS₂ to produce 2.50 L of CH₄ at STP? 4H₂(g) + CS₂(l) -> CH₄(g) + 2H₂S(g) a. 10.0 L b. 2.50 L c. 5.00 L d. 7.50 L

a. 10.0 L

if 1 egg and 1/3 cup of oil are needed for each bag of brownie mix, how many bags of brownie mix do you need if you want to use up all 3 eggs and 1 cup of oil? a. 3 b. 1 c. 2 d. 4

a. 3

which of the following would be the limiting reagent in the reaction shown below? 2H₂(g) + O₂(g) -> 2H₂O(g) a. 50 molecules of O₂ b. 50 molecules of H₂ c. neither a nor a is limiting d. both a and b are considered limiting reagents

a. 50 molecules of O₂

calcium oxide, or lime, is produced by the thermal decomposition of limestone in the reaction CaCO₃(s) (triangle)/-> CaO(s) + CO₂(g). what mass of lime can be produced from 1.5x10⁵ kg of limestone? a. 8.4x10² kg b. 8.4 kg c. 8.4x10⁵ kg d. none of the above

a. 8.4x10² kg

which of the following is NOT a reason why actual yield is less than theoretical yield? a. conservation of mass b. competing side reactions c. impure reactants present d. loss of product during purification

a. conservation of mass

which type of stoichiometric calculation does not require the use of the molar mass? a. volume-volume problems b. mass-mass problems c. mass-particles problems d. mass-volume problems

a. volume-volume problems

the amount of product formed when a reaction is carried out in the laboratory

actual yield

which conversion factor do you use first to calculate the number of grams of CO₂ produced by the reaction of 50.6 g of CH₄ with O₂? the equation for the complete combustion of methane is: CH₄(g) + 2O₂(g) -> CO₂(g) + 2H₂O(l) a. 44.0 g CO₂/2 mol CO₂ b. 1 mol CH₄/16.0 g CH₄ c. 16.0 g CH₄/1 mol CO₄ d. 2 mol O₂/1 mol CO₂

b. 1 mol CH₄/16.0 g CH₄

how many grams of chromium are needed to react with an excess of CuSO₄ to produce 27.0 g Cu? 4NH₃(g) + 6NO(g) -> 5N₂(g) + 6H₂O(g) a. 18.0 g b. 14.7 g c. 33.2 g d. 81.5

b. 14.7 g

hydrogen gas can be produced by reacting aluminum with sulfuric acid. how many moles of sulfuric acid are needed to completely react with 15.0 mol of aluminum? 2Al(s) + 3H₂SO₄(aq) -> Al₂(SO₄)₃(aq) + 3H₂(g) a. 10.0 mol b. 22.5 mol c. 15.0 mol d. 0.100 mol

b. 22.5 mol

hydrogen gas is produced when zinc reacts with hydrochloric acid. if the actual yield of this reaction is 85%, how many grams of zinc are needed to produce 112 L of H₂ at STP? Zn(s) + 2HCl(aq) -> ZnCl₂(s) + H₂(g) a. 280 g b. 380 g c. 180 g d. 95 g

b. 380 g

which of the following is true about the total number of reactants and the total number of products in the reaction shown? C₅H₁₂(l) + 80₂(g) -> 5CO₂(g) + 6H₂O(g) a. 9 grams of reactants chemically change into 11 grams of product b. 9 moles of reactants chemically change into 11 grams of product c. 9 atoms of reactants chemically change into 11 grams of product d. 9 liters of reactants chemically change into 11 grams of product

b. 9 moles of reactants chemically change into 11 grams of product

what is conserved in the reaction shown below? N₂(g) + 3F₂(g) -> 2NF₃(g) a. mass only b. mass and atoms only c. moles only d. atoms only

b. mass and atoms only

which of the following is NOT true about "yield"? a. the percent yield is the ratio of the actual yield to the theoretical yield b. the actual yield may be different from the theoretical yield because insufficient limiting reagent was used c. the value of the actual yield must be given in order for the percent yield to be calculated d. the actual yield may be different from the theoretical yield because reactions do not always go to completion

b. the actual yield may be different from the theoretical yield because insufficient limiting reagent was used

which starement is true if 12 mol CO and 12 mol Fe₂O₃ are allowed to react? 3CO(g) + Fe₂O₃(s) -> 2Fe(s) + 3CO₂(g) a. the limiting reagent is CO and 3.0 mol CO₂ will be formed b. the limiting reagent is CO and 8.0 mol Fe will be formed c. the limiting reagent is Fe₂O₃ and 36 mol CO₂ will be formed d. the limiting reagent is Fe₂O₃ and 24 mol Fe will be formed

b. the limiting reagent is Co and 8.0 mol Fe will be formed

when 0.1 mol of calcium reacts with 880 g of water, 2.24 L of hydrogen gas form (at STP). how would the amount of hydrogen produced change if the volume of water was decreased to 440 mL (440 g)? a. the volume of hydrogen produced would double b. the volume of hydrogen produced would be the same c. only one half the volume of hydrogen would be produced d. no hydrogen would be produced

b. the volume of hydrogen produced would be the same

calculate the number of moles of Al₂O₃ that are produced when 0.60 mol of Fe is produced in the following reaction. 2Al(s) + 3FeO(s) -> 3Fe(s) + Al₂O₃(s) a. 0.60 mol b. 0.40 mol c. 0.20 mol d. 0.90 mol

c. 0.20 mol

How many moles of H₃PO₄ are produced when 71.0 g P₄O₁₀ reacts completely to form H₃PO₄? P₄O₁₀(s) + 6H₂O(l) -> 4H₃PO₄(aq) a. 16.0 mol b. 4.00 mol c. 1.00 mol d. 0.0635 mol

c. 1.00 mol

how many moles of glucose, C₆H₁₂O₆, can be "burned" biologically when 10.0 mol of oxygen is available? C₂H₁₂O₆(s) + 6O₂(g) -> 6CO₂(g) + 6H₂O(l) a. 60.0 mol b. 53.3 mol c. 1.67 mol d. 0.938 mol

c. 1.67 mol

how many grams of beryllium are needed to produce 36.0 g of hydrogen? (assume an excess of water.) Be(s) + 2H₂O(l) -> Be(OH)₂(aq) + H₂(g) a. 3.2 mol b. 1.2 mol c. 1.8 mol d. 2.4 mol

c. 1.8 mol

when iron rusts in air, iron(III) oxide is produced. how many of oxygen react with 2.4 mol of iron in the rusting reaction? 4Fe(s) +3O₂(g) -> 2Fe2O₃(s) a. 3.2 mol b. 1.2 mol c. 1.8 mol d. 2.4 mol

c. 1.8 mol

mercury can be obtained by reacting mercury(II) sulfide with calcium oxide. how many grams of calcium oxide are needed to produce 36.0 g of Hg? 4HgS(s) + 4CaO(s) -> 4Hg(l) + 3CaS(s) +CaSO₄ a. 13.4 g b. 7.56 g c. 10.1 g d. 1.80 g

c. 10.1 g

metallic copper is formed when aluminum reacts with copper(II) sulfate. how many grams of metallic copper can be obtained when 54.0 g of Al react with 319 g of CuSO₄? Al + 3CuSO₄ -> Al₂(SO₄)₃ + 3Cu a. 21.2 g b. 381 g c. 127 g d. 162 g

c. 127 g

which of the following is an INCORRECT interpretation of the balanced equation shown below? 2S(s) + 3O₂(g) -> 2SO₃(g) a. 2 atoms S + 3 molecules O₂ -> 2 molecules SO₃ b. 2 mol S + 3 mol O₂ -> 2 mol SO₃ c. 2 g S + 3 g O₂ -> 2 g SO₃ d. none of the above

c. 2 g S + 3 g O₂ -> 2 g SO₃

the equation below shows the decomposition of lead nitrate. how many grams of oxygen are produced when 11.5 g NO₂ is formed? 2Pb(NO₃)₂(s) -> 2PbO(s) + 4NO₂(g) + O₂(g) a. 32.0 g b. 1.00 g c. 2.00 g d. 2.88 g

c. 2.00 g

methane and hydrogen sulfide form when hydrogen reacts with carbon disulfide. identify the excess reagent and calculate how much remains after 36 L of H₂ reacts with 12 L of CS₂. 4H₂(g) + CS(g) -> CH₄(g) + 2H₂S(g) a. 9 L CS₂ b. 6 L CS₂ c. 3 L CS₂ d. 12 L H₂

c. 3 L CS₂

in a particular reaction between copper metal and silver nitrate, 12.7 g Cu produced 38.1 g Ag. what is the percent yield of silver in this reaction? Cu + 2AgNO₃ -> Cu(NO₃)₂ + 2Ag a. 176% b. 56.7% c. 88.2% d. 77.3%

c. 88.2%

Glucose, C₆H₁₂O₆, is a good source of food energy. when it reacts with oxygen, carbon dioxide and water are formed. how many liters of CO₂ are produced when 126 g of glucose completely react with oxygen? C₆H₁₂O(s) + 6O₂(g) + 6H₂O(l) + 673 kcal a. 4.21 L b. 15.7 L c. 94.1 L d. 5.33 L

c. 94.1 L

in every chemical reaction, ___. a. mass and molecules are conserved b. moles and molecules are conserved c. mass and atoms are conserved d. moles and liters are conserved

c. mass and atoms are conserved

in any chemical reaction, the quantities that are preserved are___. a. mass and moles b. the number of molecules and the volumes c. mass and number of moles d. the number of moles and volumes

c. mass and number of moles

what is conserved in the reaction shown below? H₂(g) + Cl₂(g) -> 2HCl(g) a. mass only b. mass, moles, and molecules only c. mass, moles, molecules, and volume d. mass and moles only

c. mass, moles, molecules, and volume

how many moles of aluminum are needed to react completely with 1.2 mol of FeO? 2Al(s) + 3FeO(s) -> 3Fe(s) + Al₂O₃(s) a. 2.4 mol b. 1.2 mol c. 1.6 mol d. 0.8 mol

d. 0.8 mol

in the reaction 2CO(g) + O₂(g) -> 2CO₂(g), what is the ratio of moles of oxygen used to moles of CO₂ produced? a. 2:1 b. 1:1 c. 2:2 d. 1:2

d. 1:2

how many liters of NH₃ are needed to react completely with 30.0 L of NO (at STP)? 4NH₃(g) + 6NO(g) -> 5N₂(g) + 6H₂O(g) a. 7.5 L b. 5.0 L c. 120.0 L d. 20.0 L

d. 20.0 L

aluminum reacts with sulfuric acid to produce aluminum sulfate and hydrogen gas. how many grams of aluminum sulfate would be formed if 250 g H₂SO₄ completely reacted with aluminum? 2Al(s) + 3H₂SO₄(aq) -> Al₂(SO₄)₃(aq) + 3H₂(g) a. 450 g b. 0.85 g c. 870 g d. 290 g

d. 290 g

Iron (III) oxide is formed when iron combines with oxygen in the air. How many grams of Fe₂O₃ are formed when 16.7 g of Fe reacts completely with oxygen? 4Fe(s) + 3O₂(g) -> 2Fe₂O₃(s) a. 45 g b. 0.43 g c. 270 g d. 6.8 g

d. 6.8 g

what is the maximum number of grams of PH₃, that can be formed when 6.2 g of phosphorus reacts with 4.0 g of hydrogen to form PH₃? P₄(g) = 6H₂(g) -> 4PH₃(g) a. 45 g b. 0.43 g c. 270 g d. 6.8 g

d. 6.8 g

when glucose is consumed, it reacts with oxygen in the body to produce carbon dioxide, water, and energy. how many grams of carbon dioxide would be produced if 45 g of C₆H₁₂O₆ completely reacted with oxygen? a. 11 g b. 1.5 g c. 1.8 g d. 66 g

d. 66 g

identify the limiting reagent and the volume of CO₂ formed when 11 L CS₂ reacts with 18 L O₂ to produce CO₂ gas and SO₂ gas at STP CS₂(g) + 3O₂(g) -> CO₂(g) + 2SO₂(g) a. CS₂; 5.5 L CO₂ b. CS₂; 11 L CO₂ c. O₂; 27 L CO₂ d. O₂; 6.0 L CO₂

d. O₂; 6.0 L CO₂

in a chemical reaction, the mass of the products ___. a. is greater than the mass of the reactants b. has no relationship to the mass of the reactants c. is less than the mass of the reactants d. is equal to the mass of the reactants

d. is equal to the mass of the reactants

the reactant that is not completely used up in a reaction

excess reagent

the reactant that determines the amount of product that can be formed in a reaction

limiting reagent

this is conserved in every ordinary chemical reaction

mass

this quantity can always be used in the same way as moles when interpreting balanced chemical equations

number of molecules

the ratio of the actual yield to the theoretical yield

percent yield

the maximum amount of product that could be formed from given amounts of reactants

theoretical yield

this is conserved only in reactions where the temperature is constant and the number of moles of gaseous reactants is the same as that of gaseous products.

volume