Passage IV

An ideal gas is a hypothetical gas that behaves exactly as predicted by the ideal gas law. Depending on the conditions, an ideal gas may or may not be a good model for a real gas. The compressibility factor (z) is a value that quantifies the deviation of a gas from ideal behavior. Figure 1 shows, for an ideal gas and for 5 real gases, how z varies with pressure (in atmospheres, atm) at 0 ℃. Table 1 shows how the volume of 1 mole (6 × 1023 atoms or molecules) of gas varies with pressure for an ideal gas, for 3 of those 5 real gases, and for air.

Figure and table adapted from E. D. Eastman and G. R. Rollefson, Physical Chemistry, 1st ed. ©1947 by McGraw-Hill Book Co.

23. Based on Table 1, at 40 atm, the volume of 1 mole of CH4 at a temperature of -30℃ will most likely be:

Answer and Explanation

Your Answer is

Correct Answer is A

Explanation

Look at CH4 in table 1, when the pressure is 40 atm, its volume is 499;

Then because the condition required by the title is -30°C, And the temperature in table 1 is 0°C. Therefore, the lower the temperature, the lower the pressure of the gas, so the volume at -30°C must be less than 499, only the less than 500 mL of option A meets