객관식
What volume (in liters) is occupied by 500 g of fluorine gas (F_2) at 5.00 °C and a pressure of 735 torr? (Use R = 0.0821 L·atm·mol^{-1}·K^{-1})
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7. Gases
The Ideal Gas Law Applications
객관식
Which of the following is closest to the vapor pressure of propanone (acetone) at 45 °C?
A
80 kPa
B
56 kPa
C
101 kPa
D
40 kPa
검증된 단계별 안내1
Identify the key concept: vapor pressure is the pressure exerted by a vapor in equilibrium with its liquid at a given temperature. It depends strongly on temperature and the nature of the liquid.
Recall or find the vapor pressure data for propanone (acetone) at 45 °C from a reliable source such as a vapor pressure table or graph. Vapor pressure values are often tabulated or can be estimated using the Antoine equation.
If using the Antoine equation, the formula is: \(\log_{10} P = A - \frac{B}{C + T}\), where \(P\) is the vapor pressure, \(T\) is the temperature in °C, and \(A\), \(B\), and \(C\) are substance-specific constants. Plug in the constants for acetone and the temperature 45 °C to calculate \(P\).
Convert the vapor pressure to the desired units if necessary (e.g., from mmHg to kPa) using the conversion factor: \(1\ \text{atm} = 101.3\ \text{kPa} = 760\ \text{mmHg}\).
Compare the calculated or looked-up vapor pressure value to the given options (80 kPa, 56 kPa, 101 kPa, 40 kPa) and select the closest one.
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