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        moles and balancing equations
       
                  
        098 (part 1 of 1) 10 points from the complete combustion of 75.3 grams
 of cyclohexane? Answer in units of g.
 103 (part 1 of 1) 10 points
 How many grams of water can be produced
 from the complete combustion of 67 grams of
 cyclohexene? Answer in units of grams.
 104 (part 1 of 1) 10 points
 83 grams of sulfur are burned completely to
 form sulfur trioxide. The sulfur trioxide is
 bubbled through water to form H2 SO4 . How
 much H2 SO4 should one produce by this pro-
 cess? The equation may be written as
 2 S + 3 O2 + 2 H2 O _ 2 H2 SO4 .
 Answer in units of g.
 105 (part 1 of 1) 10 points
 Diamonds burn to form CO2 which is the
 constituent of dry ice. How many carats of
 diamonds must be burned if all of the CO2
 were to form 21 grams of dry ice? 1 carat =
 200 mg. Answer in units of carat.
 106 (part 1 of 1) 10 points
 Consider the reaction
 How many grams of CO2 can be obtained
 from the complete combustion of 75 grams of
 neopentane? Answer in units of g.
 099 (part 1 of 1) 10 points
 How many grams of H2 O can be obtained
 from the complete combustion of 76 g of
 neopentane? Answer in units of g.
 100 (part 1 of 1) 10 points
 How many grams of H2 O can be obtained
 from the complete combustion of 75 grams of
 methylbenzene? Answer in units of g.
 101 (part 1 of 1) 10 points
 How many grams of CO2 can be prepared
 from the complete combustion of 78.8 grams
 of methylbenzene? Answer in units of g.
 102 (part 1 of 1) 10 points
 How many grams of CO2 can be produced
 3 Fe + 4 H2 O _ Fe3 O4 + 4 H2
 How much iron is needed for the production
 of 32.3 ng of Fe3 O4 (FW = 232 u)? Answer
 in units of atoms.
 107 (part 1 of 1) 10 points
 For the reaction
 CaCO3 _ CaO + CO2 ,
 how much CaCO3 would have to be decom-
 posed to produce 259 g of CaO? Answer in
 units of mol.
 108 (part 1 of 1) 10 points
 For the reaction
 CaCO3 _ CaO + CO2
 how much CaCO3 would have to be decom-
 posed to produce 259 g of CaO? Answer in
 units of g.
 Herreros, Stephen – Homework 2 – Due: Feb 25 2007, midnight – Inst: Sergio Cartas 10
 109 (part 1 of 1) 10 points
 Consider the reaction
 H3 PO4 + 3 NaOH _ Na3 PO4 + 3 H2 O
 How much Na3 PO4 can be prepared by the
 reaction of 8.36 g of H3 PO4 with an excess of
 NaOH? Answer in units of g.
 110 (part 1 of 1) 10 points
 Consider the reaction
 in air. Some of the NO2 reacts with water
 in the air as shown below to form nitric acid
 (HNO3 ), a ma jor contributor to acid rain.
 Suppose that 4.3 tons of NO2 are released
 into the atmosphere, and that 100% of this
 NO2 reacts as shown.
 3 NO2 + H2 O _ 2 HNO3 + NO
 How much atmospheric HNO3 would be
 formed in this way? Answer in units of tons.
 115 (part 1 of 1) 10 points
 H3 PO4 + 3 NaOH _ Na3 PO4 + 3 H2 O
 How much Na3 PO4 can be prepared by the
 reaction of 26.4 g of NaOH with an excess of
 H3 PO4 ? Answer in units of grams.
 111 (part 1 of 1) 10 points
 Consider the reaction
 CH4 + 2 O2 _ CO2 + 2 H2 O
 What is the total mass of products formed
 when 7.5 g of CH4 is burned in air? Answer
 in units of grams.
 112 (part 1 of 1) 10 points
 Consider the reaction
 Ca3 P2 + 6 H2 O _ 3 Ca(OH)2 + 2 PH3 (g)
 What volume can be produced from the
 complete reaction of 2.58868 dg of Ca3 P2 (FW
 = 182 u)? The density of PH3 (g) at STP is
 1.52 g/L. Answer in units of liters.
 113 (part 1 of 1) 10 points
 For the reaction
 2 Al + 6 HCl _ Al2 Cl6 + 3 H2
 how much hydrogen can be formed when 75 g
 of aluminum reacts with excess hydrochloric
 acid? Answer in units of g.
 114 (part 1 of 1) 10 points
 Nitrogen dioxide (NO2 ) is a serious air pol-
 lutant that is formed when fuels are burned
 How much water can be made from 7.52 _
 1024 hydrogen molecules? Answer in units of
 g.
 116 (part 1 of 1) 10 points
 When a 13 g sample of a metal is heated in air
 25 g of product is formed. How many moles
 of oxygen atoms were involed in the reaction?
 Answer in units of mol.
 117 (part 1 of 2) 0 points
 When 8.4 g of an unknown compound X was
 dissolved in 86 g of benzene, the vapor pres-
 sure of the benzene decreased from 70.3 Torr
 to 62.1 Torr. What is the mole fraction of X?
 118 (part 2 of 2) 0 points
 What is the molar mass of X? Answer in units
 of g/mol.
 119 (part 1 of 1) 10 points
 It is a fact that limestone decomposes into a
 fixed air (a gas) and a solid called lime. A
 sample (14 g) of limestone was heated to a
 constant mass of 6.4 g. What is the percent of
 fixed air in this sample of limestone? Answer
 in units of %.
 120 (part 1 of 1) 10 points
 When a 10.49 g sample of metal is heated
 in air, 203.1 g of product is formed. What
 percent (by weight) of metal is present in the
 product? Answer in units of % metal.
 121 (part 1 of 1) 10 points
 A sample of magnesium (13 g) when heated inair produces 25 g of product. What percent
 (by weight) of magnesium is present in the
 product? Answer in units of %.
 122 (part 1 of 1) 10 points
 One of the steps involved in isolating uranium
 from its ore is reacting the ore with fluorine
 to form uranium hexafluoride (UF6 ) in the
 reaction
 U + F6 _ UF6 .
 If 4.6 g of UF6 are recovered from 54 kg of
 ore, what is the weight % of uranium in the
 ore? Answer in units of %.
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