Thermo Chemistry

How much heat must be added to a 9.81 g sample of gold to increase its temperature by 6.5°C? The specific heat of gold is 0.13J/g•°C

• 160.512 Joules

• 8.289 Joules

• 185.142 Joules

• 185,142 Joules

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

How many grams of water are needed to raise the temperature by 17°C, and using 350 J of energy?

• 4.62 grams

• 4.92 grams

• 4.58 grams

• 5.01 grams

Tags

NGSS.HS-PS3-4

How many grams of Aluminum are needed to raise the temperature by 12°C, and using 50 J of energy? Specific heat of Aluminum is 0.902 J/g•°C

• 4.62 grams

• 4.58 grams

• 4.92 grams

• 5.01 grams

Tags

NGSS.HS-PS3-1

NGSS.HS-PS3-4

The mass of a sample is 30g. There’s a temperature change from 18°C to 35°C when it absorbed 625 J of heat. What is the specific heat of this sample?

• 2.78 J/g•°C

• 8.67 J/g•°C

• 1.23 J/g•°C

• 108.67 J/g•°C

Tags

NGSS.HS-PS3-1

NGSS.HS-PS3-4

An alloy of unknown composition is heated to 153°C and placed into 100.0 g of water at 25°C. If the final temperature of the water ws 36.4°C, and the alloy weighed 3.85 g, what is the specific heat of the alloy?

• 108.67 J/g•°C

• 1.23 J/g•°C

• 2.78 J/g•°C

• 8.67 J/g•°C

Tags

NGSS.HS-PS3-1

NGSS.HS-PS3-4

How many grams of water are needed to raise the temperature by 18°C, and using 345.0 J of energy?

• 4.58 grams

• 4.62 grams

• 4.92 grams

• 5.01 grams

Tags

NGSS.HS-PS3-1

NGSS.HS-PS3-4

Which of the following correctly explains what is occurring in the reaction below? 2 Na(s) + Cl2(g) --> 2 NaCl(s)

• The reaction is endothermic because energy is being released when bonds between Na and Cl₂ are formed.

• The reaction is exothermic because energy is being released when bonds between Na and Cl₂ are formed.

• The reaction is endothermic because energy is being absorbed to transform Cl_2(g) into Cl_(s).

• The reaction is exothermic because energy is being absorbed to transform Cl_2(g) into Cl_(s).

Tags

NGSS.HS-PS1-4

For a classroom demonstration, a chemistry teacher puts samples of two different pure solid powders in a beaker. The teacher places the beaker on a small wooden board with a wet surface, then stirs the contents of the beaker. After a short time the students observe that the bottom of the beaker is frozen to the wood surface. The teacher asks the students to make a claim about the observation and to justify their claims. Which of the following is the best claim and justification based on the students' observation?

• An exothermic chemical change occurred because heat flowed from the contents of the beaker to the room.

• An exothermic physical change occurred because heat flowed from the contents of the beaker and the water on the board to the room.

• An endothermic physical change occurred because the freezing of water is an endothermic process.

• An endothermic chemical change occurred because the temperature of the beaker and the water on the board decreased as heat was absorbed by the reaction.

Tags

NGSS.HS-PS3-4

What is the enthalpy change when 10 g of water is heated from 25°C to 75°C? The specific heat capacity of water is 4.18 J/g°C.

• A) 2090 J

• B) 4180 J

• C) 20900 J

• D) 41800 J

Tags

NGSS.HS-PS3-1

NGSS.HS-PS3-2

Which of the following processes is endothermic?

• A) Combustion of methane

• B) Melting of ice

• C) Condensation of steam

• D) Freezing of water

Tags

NGSS.MS-PS1-4