1.
When a material is heated:
Correct Answer
D. The total internal energy of the substance will be increased
Explanation
When a material is heated, the total internal energy of the substance will be increased. Heating a material causes the molecules within it to gain kinetic energy, resulting in increased movement and vibration of the molecules. This increased molecular motion leads to a higher internal energy for the substance.
2.
A hot water tap delivers water at 80 degree Celsius. Ten liters of hot water is added to a pail containing 30 liters of water at 20 degree Celsius. Ignoring energy losses to the surrounding environment, what will be the final temperature of the water int he pail?
Correct Answer
C. 35 degree Celcius
Explanation
When hot water is added to the pail containing water at a lower temperature, heat is transferred from the hot water to the cooler water. The amount of heat transferred can be calculated using the equation Q = mcΔT, where Q is the heat transferred, m is the mass of the water, c is the specific heat capacity of water, and ΔT is the change in temperature. Since the specific heat capacity of water is constant, the heat transferred is directly proportional to the change in temperature. In this case, 10 liters of hot water at 80 degrees Celsius is added to 30 liters of water at 20 degrees Celsius. The total mass of the water is 40 liters, and the change in temperature is 80 - 20 = 60 degrees Celsius. Therefore, the final temperature of the water in the pail will be (60/40) * 10 + 20 = 35 degrees Celsius.
3.
50 grams of iron is heated over a flame for several minutes. It is then plunged into a closed container containing 1.0 litre of cold water, originally at 15 degree Celcius. After the temperatures equalize, the water is now found to be at 17 degree Celcius. If no water changed state to become steam and there were no losses to the surrounding environment, what was the temperature of the iron just prior to being immersed in the water?
Correct Answer
A. 399 degree Celcius
Explanation
Use the Q = mcθ.
4.
A balloon is filled with helium gas to a volume of 30 litres at 1.0 atm pressure. The balloon is released and rises to an altitude where its volume expands to 180 litres. Calculate the pressure being exerted on the balloon at thins altitude.
Correct Answer
C. 0.17 atm
Explanation
Use Boyle's Law.
5.
A fixed volume of gas has a pressure of 0.85 atm at 20 degree Celcius. The gas is heated to 85 degree Celcius. What is the new pressure?
Correct Answer
B. 1.0 atm
Explanation
Use Gay-Lussac's Law or simply the Pressure Law.
6.
A sample of air at room temperature has a volume of 90.0 mL at 95.0 kPa pressure. If the air remains at room temperature, what volume will it occupy if the pressure is changed to 40.0 kPa?
Correct Answer
D. 213.75 mL
Explanation
Use Boyle's Law.
7.
At 1 atm pressure and 25 degree Celcius, a gas-filled balloon has a volume of 20.0 L. The balloon is cooled down to -5 degree Celcius. What would be the volume of the balloon now, assuming pressure remains constant?
Correct Answer
D. 17.99 L
Explanation
Use Gay-Lussac's Law or simply the Pressure Law.
8.
What is it called when heat transfers from one object to another?
Correct Answer
E. Conduction
Explanation
Conduction is the correct answer because it refers to the process of heat transfer between objects that are in direct contact with each other. In conduction, heat energy is transferred through the collision of particles within the objects, causing the hotter object to transfer heat to the cooler object until they reach thermal equilibrium.
9.
What happens to the molecules of a substance as it gets cooler?
Correct Answer
D. The molecules move slower
Explanation
As a substance gets cooler, the kinetic energy of its molecules decreases. This causes the molecules to move slower. When the molecules move slower, they have less energy to overcome intermolecular forces, which results in a decrease in the overall movement and vibration of the molecules. Therefore, the correct answer is that the molecules move slower as the substance gets cooler.
10.
Which of the following is responsible for bringing heat to our planet?
Correct Answer
C. Radiation
Explanation
Radiation is responsible for bringing heat to our planet. Radiation is the transfer of energy through electromagnetic waves, such as heat from the Sun reaching the Earth. Unlike conduction and convection, which require a medium to transfer heat, radiation can occur through empty space. Therefore, radiation is the primary mechanism by which heat is transferred from the Sun to the Earth, making it responsible for bringing heat to our planet.