Worksheets17.1 and 17.4 Practice Test
Total questions: 33
Worksheet time: 1hrs 22mins
In an exothermic process the surroundings lose heat.
True
False
A reaction is performed in a beaker with a temperature probe recording the temperature changes of the reaction. If the temperature began at 15.0 degrees Celsius and ended at 27.5 degrees Celsius. If the reaction is our system, is the system endothermic or exothermic?
Exothermic
Endothermic
During an endothermic reaction in a beaker if we are part of the surroundings and touched the beaker, it would feel _______.
Warm
Cold
Bubbly
Damp
The diagram represents two solids and the temperature of each. What occurs when the two solids are placed in contact with each other?
Heat energy flows from solid A to solid B. Solid A decreases in temperature
Heat energy flows from solid A to solid B. Solid A increases in temperature
Heat energy flows from solid B to solid A. Solid B decreases in temperature.
Heat energy flows from solid B to solid A. Solid B increases in temperature.
The amount of heat energy required to change the temperature of 12 g of gold from 45°C to 15°C is -47 J. What is the specific heat capacity of gold?
0.13 J/(g°C)
17,000 J/(g°C)
1600 J/(g°C)
0.065 J/(g°C)
A cast iron skillet is used to fry bacon. For optimal frying, the pan must be heated to about 178 oC from a room temperature of 22.0 oC. It is known that 1.58 x 105 J of heat energy are absorbed by the pan to reach the desired temperature and the specific heat of iron is 0.450 J/g oC. What must the mass of the skillet be?
12.7 kg
2.25 kg
110 kg
1.97 kg
Which of the following is an endothermic process?
gas to gas
liquid to solid
solid to liquid
gas to liquid
20 g of water with a specific heat of 4.18 J/g°C undergoes a temperature change from 25° C to 20° C. How much heat energy (q) moves from the water to the surroundings?
418 J
210 J
80 J
4.18 J
What is the specific heat of an unknown substance if 100.0 g of it at 200.0 °C reaches an equilibrium temperature of 27.1 °C when it comes in contact with a calorimeter of water and releases 2225J of heat energy?
0.111 J/g°C
1.29 J/g°C
0.129 J/g°C
22225.85 J
How much heat does an aluminum block absorb if 10.00 grams are heated from 25.0oC to 50.0oC? The specific heat of aluminum is .900J/goC
450
-450
225
-225
How do you calculate Enthalpy of a reaction?
ΔH = ΔHproducts - ΔHreactants
ΔT = q / mC
ΔG = ΔH -TΔS
E = mc2
Use the information below to determine the correct expression to calculate the enthalpy of formation of methane.
C(s)+O2(g)→CO2(g); ΔrH∘=−393.5kJ
2H2(g)+O2(g)→2H2O(l); ΔrH∘=−571.8kJ
CH4(g)+2O2(g)→CO2(g)+2H2O(l); ΔrH∘=−890.3kJ
394 + (2 × 286) – 891
–394 – (2 × 286) + 891
891 - [ -394 + (2 x -286)]
–394 – 286 + 891
You are given these two equations:
2H2 + O2 → 2H2O ∆H = -572 kJ
H2 + O2 → H2O2 ∆H = -188 kJ
ΔH is the same thing as:
temperature
q
m
C
A positive ΔH means the reaction is:
complete
at equilibrium
exothermic
endothermic
C(s, graphite) + 1⁄2O2(g) --> CO(g) cannot be measured directly since some carbon dioxide is always formed in the reaction.
It can be calculated using Hess’s Law and the enthalpy changes of combustion of graphite and of carbon monoxide.
C(s, graphite) + O2(g) --> CO2 ΔH=-394 kJmol–1
CO(g) + 1⁄2O2(g) --> CO2 ΔH=-283 kJmol–1
The enthalpy change for the reaction of graphite with oxygen to give carbon monoxide is
ΔH○f [Fe2O3(s)] = –820 kJ mol–1
Select the expression which gives the enthalpy change, in kJ mol–1, for the reaction:
2FeO(s) + 1⁄2O2(g) → Fe2O3(s)
What is the enthalpy change under standard conditions for the following reaction?
3FeO(s) + 2Al (s) -> 3Fe(s) + Al2O3(s)
We can determine the change in enthalpy for a reaction by using _____ values for ΔH.
positive
published
negative
experimental
