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CHM 2045
Which of the following statements about mass spectrometry is false?
A)
Mass spectrometry can be used to determine the molecular weight of a compound.
B)
The curvature of the path in a magnetic field is determined by the mass of the ion.
C)
The paths of heavier ions are deflected more strongly than the paths of lighter ions.
D)
The sample is changed into positively charged ion
If the density of ethanol, C 2
H
OH, is 0.789 g/mL. How many milliliters of ethanol are
needed to produce 15.0 g of CO 2
according to the following chemical equation?
C
H
OH( l ) + 3 O 2
( g ) 2 CO 2
( g ) + 3 H 2
O( l )
A)
6.19 mL
B)
9.95 mL
C)
19.9 mL
D)
39.8 mL
If the percent yield for the following reaction is 75.0%, and 45.0 g of NO 2
are consumed in
the reaction, how many grams of nitric acid, HNO 3
( aq ) are produced?
3 NO
( g ) + H 2
O( l ) 2 HNO 3
( aq ) + NO( g )
A)
30.8 g
B)
41.1 g
C)
54.8 g
D)
69.3 g
Which substance is the limiting reactant when 2.0 g of sulfur reacts with 3.0 g of oxygen
and 4.0 g of sodium hydroxide according to the following chemical equation:
2 S( s ) + 3 O 2
( g ) + 4 NaOH( aq ) 2 Na 2
SO
( aq ) + 2 H 2
O( l )
A)
S( s )
B)
What is the concentration of NO 3
ions in a solution prepared by dissolving 25.0 g of
Ca(NO 3
in enough water to produce 300. mL of solution?
A)
0. 254 M
B)
0. 508 M
C)
0. 672 M
D)
1.02 M
How many milliliters of a 9.0 M H 2
SO
solution are needed to make 0. 35 L of a 3.5 M
solution?
A)
- 14 mL
B)
0.90 mL
C)
140 mL
D)
900 mL
A FeCl 3
solution is 0.175 M. How many mL of a 0.175 M FeCl 3
solution are needed to
make 450. mL of a solution that is 0.300 M in Cl
ion?
A)
0.771 mL
B)
257 mL
C)
771 mL
D)
It is not possible to make a more concentrated solution from a less concentrated solution.
A student prepared a stock solution by dissolving 10.0 g of KOH in enough water to make
- mL of solution. She then took 15.0 mL of the stock solution and diluted it with enough
water to make water to make 65.0 mL of a final solution. What is the concentration of KOH
for the final solution?
A)
0. 274 M
B)
0. 356 M
C)
2.81 M
D)
3.65 M
How many grams of CaCl 2
are formed when 15.00 mL of 0.00237 M Ca(OH) 2
reacts with
excess Cl 2
gas?
2 Ca(OH) 2
( aq ) + 2 Cl 2
( g ) Ca(OCl) 2
( aq ) + CaCl 2
( s ) + 2 H 2
O( l )
A)
0.00 197 g
B)
0.00 394 g
C)
0.00789 g
D)
0.0507 g
How many milliliters of 0.200 M FeCl 3
are needed to react with an excess of Na 2
S to
produce 1.38 g of Fe 2
S
if the percent yield for the reaction is 65.0%?
3 Na 2
S( aq ) + 2 FeCl 3
( aq ) Fe 2
S
( s ) + 6 NaCl( aq )
A)
33.8 mL
When 280. mL of 1.50 × 10
M hydrochloric acid is added to 125 mL of 1.75 × 10
M
Mg(OH) 2
, the resulting solution will be
A)
acidic.
B)
basic
C)
neutral.
D)
It is impossible to tell from the information given.
Combustion analysis of 1.200 g of an unknown compound containing carbon, hydrogen,
and oxygen produced 2.086 g of CO 2
and 1.134 g of H 2
O. What is the empirical formula
of the compound?
A)
C
H
O
B)
C
H
O
C)
C
H
O
D)
C
H
O
Based on the balanced chemical equation shown below, determine the mass percent of
Fe
in a 0.7450 g sample of iron ore, if 22.40 mL of a 0.1000 M stannous chloride,
SnCl 2
( aq ), solution is required to completely react with the Fe
present in the ore
sample. The chemical equation for the reaction is
2 Fe
( aq ) + Sn
( aq ) 2 Fe
( aq ) + Sn
( aq ).
A)
B)
C)
D)
- Based on the balanced chemical equation shown below, determine the molarity of a
solution containing Fe
( aq ), if 40.00 mL of the Fe
( aq ) solution is required to
completely react with 30.00 mL of a 0. 250 M potassium bromate, KBrO 3
( aq ), solution. The
chemical equation for the reaction is
6 Fe
( aq ) + BrO 3
( aq ) + 6 H
( aq ) 6 Fe
( aq ) + Br
( aq ) + 3 H 2
O( l ).
A)
0. 0312 M
B)
- According to the balanced chemical equation
5 H
C
O
( aq ) + 2 MnO 4
( aq ) + 6 H
( aq ) 10 CO 2
( g ) + 2 Mn
( aq ) + 8 H 2
O( l )
0.3500 grams of oxalic acid, H 2
C
O
will react with ________ mL of 0.100 M potassium
permanganate, KMnO 4
solution.
A) 15.5 mL B) 38.9 mL C) 77.7 mL D) 97.2 mL
What is the reduction half reaction for the chemical reaction in a basic solution
Mn
( aq ) + 2 ClO 3
( aq ) + OH
( aq ) MnO 2
( s ) + 2 ClO 2
( aq ) + H 2
O( l )?
A)
Mn
( aq ) + 4 OH
( aq ) MnO 2
( s ) + 2 H 2
O( l ) + 2e
B)
Mn
( aq ) + 2 H 2
O( l ) MnO 2
( s ) + 4 H
( aq ) + 2e
C)
ClO 3
( aq ) + H 2
O( l ) + e
ClO 2
( aq ) + 2 OH
( aq )
D)
ClO 3
( aq ) + 2 H
( aq ) + e
ClO 2
( aq ) + H 2
O( l )
- Determine the number of water molecules necessary to balance the reduction half
reaction of ( )
2
( ) ___Mn
4
___MnO aq aq
that occurs in an acidic solution.
A)
B)
C)
D)
In the unbalanced equation shown below how many moles of electrons are transferred per
mole of reducing agent?
C
O
2– ( aq ) + MnO 4
( aq ) CO 2
( aq ) + Mn
( aq )
A)
B)
C)
D)
