Which of the following is NOT true about gases? 1. The volume a gas occupies is directly proportional to its molecular weight. 2. The gas is at STP if it is at 273 K and 1 atm. 3. Gases exert pressure on their surround- ings. 4. Gases can expand without limit. 5. The density of a gas can be increased by applying increased pressure. Now I know that 1 is wrong. But I was thinking shouldn't 4 technically be wrong because the gases only expand to fill the container they are in. In other words a gas in bottle can't expand without limit. Is this reasoning correct in any way?