Which of the following is equivalent to 251 torr? A. 0.330 atm.
B. 1900 atm.
C. 29.4 psi.
D. All of these choices.

Option A. 0.330 atm.

Explanation:

To know the correct answer, we simply do the following:

1. Conversion of 251 torr to atm

760 torr = 1 atm

Therefore,

251 torr = 251 torr / 760 torr × 1 atm

251 torr = 0.330 atm

2. Conversion of 251 torr to psi

1 torr = 0.0193 psi

Therefore,

250 torr = 250 torr / 1 torr × 0.0193 psi

250 torr = 4.825 psi

From the above illustrations, 251 torr is equivalent to both 0.330 atm and 4.825 psi. Therefore, only option A is correct.