CHEMISTRY 12 – CALCULATING RATES OF REACTION WORKSHEET
1) Explain three different ways of measuring the rate of the following reaction. (3 marks)
Cu (s) + 2 H2SO4 (aq) → CuSO4 (aq) + 2 H2O (l) + SO2 (g)
rate
=
2) Consider the reaction:
2 Al (s) + 6 HCl (aq) → 2 AlCl3 (aq) + 3 H2 (g)
A 10.0 g sample of Al reacts completely in excess HCl in 300.0 s. What is the rate of production of
H2 in mol/s? (3 marks)
DmassCIrate-DVo1umeS0TDtimeDtimerate-smass_mrate-SpressureDtimestimeXtopensystenolAI3mo1H2H2m0f.10.0gAl_x-x3oo.0s27.0g2mo1Al-1.85x103mol1ss-100.0gHa0x@H20x_m002xls18.O
3) Consider the reaction:
2 H2O (l) → 2 H2 (g) + O2 (g)
The rate of production of O2 is 1.2 x 10-2 mol/s. How many seconds will it take to decompose 100.0
g of H2O? (3 marks)
g
=
230
s
2
mol
H20
1.2×10
.
2nd
02
4) Consider the following reaction:
2 Al (s) + 6 HCl (aq) → 2 AlCl3 (aq) + 3 H2 (g)
In an experiment, Al is placed into some HCl, and the following data is collected:
Time
(min)
Mass of Al
(g)
0.0
5.67
90.0
1.10
Calculate the rate of this reaction in grams of H2 produced per minute. (4 marks)
Al
g
5.67-1.10=4579
=
gH2
=
min
457T
90.0
×
x
-
mol
Hz
2
x
-
2
27.0g
min
5.6×10-39
=
3
Al
mol
/
mol
Al
.0g
-
mol
1
H2
Hoymin
5) When a candle (C20H42) burns, the following reaction occurs:
C20H42 (s) + 61 O2 (g) → 40 CO2 (g) + 42 H2O (g) + heat
If the rate of production of CO2 is 0.98 g/min, what mass of C20H42 is consumed in 30.0 seconds?
(3 marks)
30.05×16%3×0.989=02×402
lmin
440g
gC2oH42=
,,
1m0lC2oH=×
40 mol
COL
-282.0g
1mo1C2oH42
0.079g
=
6) Consider the following reaction:
2 Al (s) + 3 CuCl2 (aq) → 2 AlCl3 (aq) + 3 Cu (s)
If the rate of consumption of Al is 0.46 g/min, how many minutes will it take to produce 0.89 g of
Cu? (4 marks)
min
=
=
0.89g
0.55mm
×
#
63.5g
×
3
#
molcu
'
×
2¥
Imd
×
Al
#
0.46g
7) The mass of a burning candle is monitored to determine the rate of combustion of paraffin. An
accepted reaction for the combustion of paraffin is:
2 C28H58 (s) + 85 O2 (g) → 56 CO2 (g) + 58 H2O (g)
a) Calculate the average rate of consumption of paraffin in g/min for the time interval 12.0 to 24.0
minutes. (2 marks)
GC 28458
245
min
have
the
,S¥m;a=
24#m;n=
=
-
I
23.49
-
kept
final
the
question
stated
positive
answer
'
'
rate
0.0925mm
of
since
consumption
"
b) Calculate the rate of CO2 production in mol/min for the time interval 12.0 to 24.0 minutes.
(2 marks)
M0lC0==
min
0.0929484T
min
I
-
=
6.5×10
3mo1/min
×
¥28458
3940g
×
56yolC=
28458
2
mol
8) Consider the following reaction:
3 Cu (s) + 8 HNO3 (aq) → 3 Cu(NO3)2 (aq) + 2 NO (g) + 4 H2O (l)
A piece of copper is added to a nitric acid solution in an open beaker, allowing the NO (g) to escape.
The following data was obtained:
a) Calculate the reaction rate for the time period 2.0 to 6.0 min. (2 marks)
g
195.45
NO
=
-
Tomin
-
Mir
188.15g
=
NO produced
1.8g
7j?o0mT=
b) Calculate the mass of copper consumed in the first 5 minutes. (3 marks)
0=200.00
g
Cu
=
=
10.10g
32.1g
-
NOX
189.90
=
10.10g
40×3+01
cu
30.0g
2
mol
NO
×
1
6¥
mol
Cu
/
min
9) An Alka-Seltzer tablet is added to water to produce carbon dioxide gas. The gas was collected using
water displacement.
Calculate the average rate of reaction for the formation of CO2 gas for the times:
a) 0.0 – 10.0 s (1 mark)
M¥02
=
3.0mL
10.0
coals
0.30mL
=
S
b) 10.0 – 20.0 s (1 mark)
M¥02
=
.:
20.O-3.0nj.RO#=1.7OmLC0a/s
20.0
-
10
10.05
10) Consider the following reaction in an open flask:
CaCO3 (s) + 2 HCl (aq) → CaCl2 (aq) + H2O (l) + CO2 (g)
A 157.0 g sample of CaCO3 (s) is placed in the flask and HCl (aq) is added. The reaction consumes
HCl (aq) at an average rate of 0.250 mol/min for 10.0 min. What mass of CaCO3 (s) remains?
(3 marks)
gcaco
}
reacted
=
10.0
250mA
minx
I
125g
remaining
-
Hclx
gcacoz
=
157.0
32g
-
125g
xp
mol
100.1g
-
2
min
=
=
IMOICACQ
HCI
MOICACG