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WorksheetsThermochemistry
Total questions: 36
Worksheet time: 20mins
During an exothermic reaction, heat content in the surroundings increases because
heat energy is destroyed during reactions
the reaction absorbs heat energy
the energy contained in the reactants is lower then the products
the energy contained in the products is lower than the reactants
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)
The graph represents the uniform heating of a substance, starting with the substance as a solid below its melting point. Which line segment listed below represents an increase in potential energy and no change in average kinetic energy?
Line segment AB
Line segment BC
Line segment CD
Line segment EF
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
Experimental Set-up for Calories in a Chocolate Chip Cookie Students designed an experiment to determine the amount of calories in a chocolate chip cookie. A ring stand was used with a clean aluminum soda can hung from the ring that was partially filled with a known mass of water. A thermometer was placed inside the can so that it measured the temperature of the water but did not touch any part of the metal can. Once set-up was complete, an initial water temperature was taken. The cookie was then lit on fire and allowed to completely burn. A final temperature of the water was measured.
Refer to the experimental set-up for calories in a chocolate chip cookie. How does this experiment allow students to measure the calories in a cookie?
The difference in masses before and after the cookie is burned is calculated, then converted into heat energy.
Heat energy from the burning cookie is transferred to the water. The change in water temperature is used to calculate the heat energy from the cookie.
Data from the amount of time for the cookie to burn and the temperature change are used to calculate the heat energy from the cookie.
The cookie is burned until the water reaches a boiling temperature, then masses are compared to calculate the heat energy from the cookie.
Respiration, bomb explosion and neutralisation of acid with alkali are the examples of _______________ reactions
exothermic
endothermic
precipitation
The energy level diagram represents
exothermic reaction
endothermic reaction
___________________ is the capacity to do work or supply heat.
energy
heat changes
specific heat
thermochemistry
Ice cream melting is an example of an __________ process.
endothermic
exothermic
what does c stand for?
heat capacity
specific heat
mass
temperature
Mass must always be in ________ for energy calculations.
kilograms
grams
joules
calories
What is the specific heat of water?
4.184 J/gC
1.00 cal/gC
All of the above
none of the above
When heat flows from system to the surroundings that is an example of an ________________ process.
exothermic
endothermic
What device is used to measure the amount of heat involved in a chemical reaction or physical process?
barometer
calorimeter
thermometer
Kinetic energy is energy gained _______________
while at rest
during motion
What is calorimetry?
process of measuring kinetic and potential energy
process of measuring heat flow of chemical reactions
process of measuring pressure and temperature of a substance
Heat flows from _______ to _________.
warm to cool
cool to warm
The specific heat of a substance varies with the mass of a sample. True or False?
True
False
1 food calorie = _______ chemistry calories
1000
1
500
4.184
Samples of two different substances having the same mass always have the same heat capacity. True or False?
True
False
What is the SI unit of heat and energy?
calorie
celsius
joule
The law of conservation of energy states that
in any chemical or physical change, energy cannot be created or destroyed, only changed in form.
heat changes occur during chemical and physical changes.
energy is the capacity to do work or to supply heat
there are two types of energy, kinetic and potential
2N2 + 3H2 --> 2NH3 + 46 kJ
How much energy would be produced if only 1 mol of nitrogen was reacted?
H2O (l) + 44.0 kJ --> H2O (g)
What mass of P4 must be reacted to produce 5905 kJ of energy? P4 + 6Cl2 --> 4PCl3 + 2439 kJ
(Atomic Mass of P= 30.97 amu)
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
Is this reaction endothermic or exothermic?
