Which of the following are correct statements? (Could be as many as 4)
1. One mole of gas contains 22.4 representative particles
2. Standard pressure is 100 mm Hg
3. One mole of a gas must have the same volume as one mole of any other gas at STP
4. Gas molecules are spaced far away from each other at STP
5. Liquids can be greatly compressed
6. Standard pressure is 101.3 atmospheres
7. Gases can be compressed
i think 1 and 3 are right..? but the other 2? is 1 & 3 right?
The correct statements are 1 and 7. Let me explain each statement:
1. One mole of gas contains 22.4 representative particles: This statement is true. Avogadro's law states that one mole of any gas at STP (standard temperature and pressure) contains 6.022 x 10^23 representative particles, which is known as Avogadro's number. For gases at STP, this corresponds to 22.4 liters of volume.
3. One mole of a gas must have the same volume as one mole of any other gas at STP: This statement is false. While one mole of any gas at STP occupies 22.4 liters, different gases have different molecular masses, so the mass of one mole of each gas will vary. Consequently, the volume of one mole of each gas will also differ, according to the ideal gas equation.
4. Gas molecules are spaced far away from each other at STP: This statement is false. At STP, gas molecules are in close proximity to each other and constantly colliding, which is why gases occupy the entire volume of their container. They are not spaced far apart.
5. Liquids can be greatly compressed: This statement is false. Liquids are generally considered to be incompressible compared to gases. While it is possible to compress liquids slightly under very high pressures, they cannot be greatly compressed like gases.
6. Standard pressure is 101.3 atmospheres: This statement is close but not entirely accurate. The standard pressure is defined as 1 atmosphere, which is equivalent to 760 mm Hg or 101.3 kPa.
So, the correct statements are 1 and 7.
To determine which of the statements are correct, let's evaluate each one individually:
1. One mole of gas contains 22.4 representative particles: This statement is correct. According to Avogadro's law, one mole of any substance, including gases, contains 6.022 x 10^23 particles. At standard temperature and pressure (STP), 22.4 liters of any gas contains one mole of particles. Therefore, statement 1 is correct.
2. Standard pressure is 100 mm Hg: This statement is not correct. Standard pressure, also known as standard atmospheric pressure, is defined as 1 atmosphere (atm) or 760 mm Hg. The statement incorrectly states 100 mm Hg as the standard pressure.
3. One mole of a gas must have the same volume as one mole of any other gas at STP: This statement is correct. At STP, one mole of any gas occupies a volume of 22.4 liters. This value is the same for all gases since it is based on the ideal gas law and Avogadro's law. Thus, statement 3 is correct.
4. Gas molecules are spaced far away from each other at STP: This statement is correct. At standard temperature and pressure, gas molecules have a relatively large amount of space between them compared to liquids or solids. This is due to the nature of gas particles, which move freely and rapidly, allowing them to occupy greater volumes. Therefore, statement 4 is correct.
5. Liquids can be greatly compressed: This statement is not correct. Liquids are generally considered to be incompressible compared to gases. While it is possible to compress liquids to some extent, the change in volume is minimal compared to gases. Therefore, statement 5 is not correct.
6. Standard pressure is 101.3 atmospheres: This statement is not correct. As mentioned earlier, standard pressure is defined as 1 atmosphere (atm) or 760 mm Hg. The statement incorrectly states 101.3 atmospheres as the standard pressure.
7. Gases can be compressed: This statement is correct. One of the characteristic properties of gases is their ability to be compressed. Since gas particles are spaced relatively far apart, exerting pressure on a gas can cause its volume to decrease. This property distinguishes gases from solids and liquids, which are generally much less compressible. Therefore, statement 7 is correct.
In conclusion, statements 1, 3, 4, and 7 are correct, while statements 2, 5, and 6 are not correct.