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 %.
