Please help!! A balloon contains 7 L of He. The pressure is reduced to 2 atm and the
balloon expands to occupy a volume of 25 L. What was the initial pressure
exerted on the balloon? (round to the nearest whole number)

The density of a planet is 0.69 g/cm3 (density of water is 1.0 g/cm3). which of the following planets might this be? a. mercury b. venus c. saturn d. mars

Alidded glass container is filled with a colored gas. after a period of time, it is observed that the gas is uniformly spread throughout the box and that the movement has slowed considerably. next, a warm iron plate is carefully placed under the box. why is there resumed movement of the gas in the container?

Kp is the equilibrium constant for dissociation of the propionic acid dimer. what is the sign of the slope for a plot of the natural logarithm of kp vs. inverse temperature for this reaction?