Unit 6 Thermodynamics

643 Joules of heat are generated and 321 Joules of work are done on the system during a chemical reaction. Calculate the change in the internal energy of the chemical system.

• -322 Joules

• 322 Joules

• 643 Joules

• 964 Joules

A chemical reaction is run in which 513 Joules of heat are absorbed and the internal energy changes by +1234 Joules. Calculate "w" for the system.

• -721 Joules

• 721 Joules

• 1747 Joules

• 1026 Joules

Tags

NGSS.HS-PS3-1

If 200 kJ of energy are evolved in a reaction, is this reaction endothermic or exothermic and what is the value of "q"?

• exothermic; 200 kJ

• exothermic; -200 kJ

• endothermic; 200 kJ

• endothermic; -200 kJ

Tags

NGSS.HS-PS1-4

Does this image depict an exothermic or endothermic reaction

• exothermic

• endothermic

Tags

NGSS.HS-PS1-4

Which energy diagram, A or B, depicts a reaction with a positive value of H?

• A

• B

Tags

NGSS.HS-PS1-4

What is the energy change when the temperature of 13.6 grams of gaseous nitrogen is decreased from 31.2 C to 23.2 C?

Specific heat of nitrogen: 1.04 J/g*C

• -109 J

• 769 J

• -113 J

• 113 J

Tags

NGSS.HS-PS3-1

NGSS.HS-PS3-4

When a sample of gaseous nitrogen is heated, 313 Joules of energy are added to a 12.4 gram sample and the final temperature is 24.7 C. What is the initial temperature of the nitrogen?

Specific heat of nitrogen: 1.04 J/g*C

• -0.429 C

• 95700 C

• 0.429 C

• 24.7 C

Tags

NGSS.HS-PS3-4

A 47 gram aluminum spoon (specific heat 0.88 J/g*C ) at 29 C is placed in 185 grams of water (specific heat 4.184 J/g*C) at 90 C and the temperature of the two become equal. What is the final temperature when the two become equal?

• 93 C

• 87 C

• -93 C

• -87 C

Tags

NGSS.HS-PS3-1

NGSS.HS-PS3-4

A 70 gram copper fork (specific heat 0.386 J/g*C ) at 20 C is placed in 170 grams of water (specific heat 4.184 J/g*C ) at 80 C and the temperature of the two become equal. What is the final temperature when the two become equal?

• 82 C

• 78 C

• -82 C

• -78 C

Tags

NGSS.HS-PS3-1

NGSS.HS-PS3-4

During an experiment, the teacher discovers that it takes 240 Joules to increase the temperature of 12.0 grams of solid aluminum from 25.4 C to 40.1 C. Calculate the specific heat of aluminum from her experiment.

• 1.36 J/g*C

• 3.66 J/g*C

• 0.900 J/g*C

• -1.36 J/g*C

Tags

NGSS.HS-PS3-1

NGSS.HS-PS3-4