Question 1

A balloon is being inflated by heating the air inside it. The volume changes from $$4.00 	imes 10^6$ L to 4.50$$ 	imes $$10^6 L$$, and $$1.3 	imes 10^8$ J of energy is added as heat. If the balloon expands against a constant pressure of 1.0 atm, what is the change in internal energy $$\Delta E$$ for the process? (Use 1$$\ \mathrm{L \cdot atm} = 101.3\ \mathrm{J}$$)

Accepted Answer

$$8 	imes 10^7$ J

Question 2

Which equation correctly relates the change in internal energy ($$\Delta E$$), heat ($$q$$), and work ($$w) $$for a system?

Accepted Answer

$$\Delta E = q + w$$

Question 3

In the context of the balloon problem, what is the correct sign for the work done by the system during expansion against a constant external pressure?

Accepted Answer

Negative, because the system does work on the surroundings

Question 4

Given $$q = +1.3 	imes 10^8$ J and w = -5.065$$ 	imes $$10^7 J$$, calculate $$\Delta E.$$

Accepted Answer

$$7.93 	imes 10^7$ J

Question 5

If the volume of a gas increases at constant pressure, what is the sign of the work done by the system?

Accepted Answer

Negative

Question 6

Which of the following best describes the energy transfer when a balloon is heated and expands?

Accepted Answer

Heat is absorbed, and work is done by the system

Question 7

Convert $$5.0 	imes 10^5$ L·atm to Joules using 1$$\ \mathrm{L \cdot atm} = 101.3\ \mathrm{J}$$.

Accepted Answer

$$5.065 	imes 10^7$ J

Question 8

A process occurs at constant pressure where the system absorbs heat and expands. Which of the following statements is true?

Accepted Answer

$$q is $$positive and $$w is $$negative

Question 9

If a system does $$5.0 	imes 10^7$ J of work on the surroundings and absorbs 1.3$$ 	imes $$10^8 J of $$heat, what is the final change in internal energy?

Accepted Answer

$$8.0 	imes 10^7$ J

Question 10

Which of the following best explains why the work done by the system is negative when a gas expands?

Accepted Answer

Because energy leaves the system as work

Question 11

A chemical reaction occurs in a sealed, rigid container. Which of the following statements is true about the work done?

Accepted Answer

No work is done

Question 12

If the external pressure is doubled while the volume change remains the same, how does the work done by the system change?

Accepted Answer

It doubles

Question 13

Which of the following is the correct formula for calculating work done by a gas at constant pressure?

Accepted Answer

$$w = -P \Delta V$$

Question 14

A balloon is heated and expands, doing $$-5.1 	imes 10^7$ J of work. If the internal energy increases by 8.0$$ 	imes $$10^7 J$$, how much heat was added?

Accepted Answer

$$1.3 	imes 10^8$ J

Calculating Internal Energy Change (ΔE) for a Balloon Expansion

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