chemistry Ideal gas law?

1. A gas exerts pressure as a result of the collisions of the gas molecules with the walls of the container.

True.

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2. All of these statements are false.

False. Because number 1 (at least) is true.

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3. At STP, 1.0 L of gaseous Ar contains about twice the number of atoms as 1.0 L of gaseous Ne

False. PV=nRT so there are equal amounts (moles) hence equal numbers of atoms.

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4. The gas particles in a sample exert attraction on one another

Ambiguous. There *is* attraction but it is negligible under normal circumstance. However at very low temperatures the attraction between atoms causes the gas to condense into a liquid. To be technically correct the answer is 'true'.

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5. The temperature of the gas sample is directly related to the average velocity of the gas particles

False. Average particle velocity = 0 for a stationary container of gas. This is because velocity is vector. A particle's velocity in one direction is cancelled out by another particle's equal magnitude velocity in the opposite direction for example. However temperature is related to average *speed* (absolute temperature is proportional to RMS speed squared to be accurate).

The first statement is correct. The last statement is ambiguous, because "directly" suggests a linear proportion, which is NOT the relationship between temperature and average speed. The temperature is directly proportional to the average molecular kinetic energy (not velocity).