Question

ich work (in J) is involved in a chemical reaction if the volume decreases from 5.00 to 1.31 L against a constant pressure of 0.822 atm? s your answer to three significant figures and include the appropriate units.

Answer 1

To calculate the work (W) done during a volume change against a constant pressure, you can use the formula:

\[
W = -P \Delta V
\]

where:
- \( P \) is the pressure in atmospheres (atm).
- \( \Delta V \) is the change in volume in liters (L).

First, we need to find the change in volume (\( \Delta V \)):

\[
\Delta V = V_{final} - V_{initial} = 1.31\, \text{L} - 5.00\, \text{L} = -3.69\, \text{L}
\]

Now, using the pressure provided (0.822 atm), we can insert the values into the work equation:

\[
W = -P \Delta V = -0.822\, \text{atm} \times (-3.69\, \text{L}) = 3.03438\, \text{L atm}
\]

Next, we need to convert this value into joules. The conversion factor from L atm to joules is approximately \( 1\, \text{L atm} = 101.325\, \text{J} \).

Now we convert:

\[
W \approx 3.03438\, \text{L atm} \times 101.325\, \text{J/L atm} \approx 307.2\, \text{J}
\]

Finally, rounding to three significant figures, the work done is:

\[
W \approx 307\, \text{J}
\]

So, the work done is **307 J**.