# Chemistry

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1. A gas initially at 10 C must be changed to _____ C to triple the pressure.

2. When a student plotted ln [vapor pressure of a gas] vs. inverse Kelvin temperature, she obtained a straight line with a slope equal to -20000 K.
According to the Clausius Clapeyron equation, change in Hvap is _____ kJ/mol.

3. A student transfers a corked flask filled with air from the ice to the room temperature water bath. In the process he inadvertently pushes the cork further into the flask. The resulting pressure measurement will be ______ (higher, lower, the same)

4. true or false statements.
-Molecular motion is negligible at absolute zero.
-Absolute zero is the temperature when P = 0.
-When pressure is plotted on the x-axis and Celsius temperature is on the y-axis, the y-intercept is absolute zero .

• Chemistry -

To triple the pressure one must triple the temperature. The trick here is to recognize that it is the Kelvin temperature and not celsius that must be triple the original T. So 10 C = 273 + 10 = 283 K and 283 x 3 = ?? K.
OR you can do it another way.
P1/T1 = P2/T2.
Now just make up something for P1 (I suggest 1), then P2 will be 3, T1 will be 283 and you can solve for T2.

• Chemistry -

lower

• Chemistry -

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