Which of the gases most closely resembles an ideal gas at standard temperature and pressure?
1) CO2
2) NH3
3) HI
4) H2
5) H2O
why would it be H2
Smallest molecule so it isn't polarizable (has no dipole moment---CO2 doesn't have one either). Essentially a pure covalent bond so it is not ionic.
The gas that most closely resembles an ideal gas at standard temperature and pressure (STP) is hydrogen (H2).
An ideal gas is a theoretical concept in which the gas particles are assumed to occupy no space and have no intermolecular forces. While no real gas exactly behaves as an ideal gas, hydrogen comes closest to meeting these ideal gas assumptions at STP.
Hydrogen gas (H2) consists of diatomic molecules that are small and have weak intermolecular forces, making their behavior similar to that of an ideal gas. Additionally, at STP (0 degrees Celsius and 1 atmosphere of pressure), hydrogen is a gas, unlike carbon dioxide (CO2), ammonia (NH3), hydrogen iodide (HI), and water (H2O), which are gases under different conditions or are liquids at STP. Therefore, the gas that most closely resembles an ideal gas at standard temperature and pressure is hydrogen (H2).
To determine which gas most closely resembles an ideal gas at standard temperature and pressure (STP), we need to consider the properties of an ideal gas. An ideal gas follows certain specific assumptions, including that it consists of point-like particles with no volume, and the intermolecular forces between the particles can be ignored.
Among the given options, the gas that most closely adheres to these assumptions is hydrogen gas (H2). Here's why:
1) CO2 (Carbon Dioxide): CO2 is a non-ideal gas because it consists of larger molecules that have significant intermolecular forces. These intermolecular forces cause deviations from ideal gas behavior.
2) NH3 (Ammonia): Ammonia also consists of larger molecules and exhibits intermolecular forces. It is not an ideal gas.
3) HI (Hydrogen Iodide): Hydrogen iodide is a polar molecule that has intermolecular forces due to hydrogen bonding. These intermolecular forces prevent it from behaving like an ideal gas.
4) H2 (Hydrogen): Hydrogen gas consists of diatomic molecules, which are very small, and it does not have significant intermolecular forces. Consequently, at STP, hydrogen gas closely resembles an ideal gas.
5) H2O (Water): Water is a polar molecule and exhibits strong intermolecular forces due to hydrogen bonding. These intermolecular forces prevent water from behaving like an ideal gas.
In summary, among the given options, hydrogen gas (H2) most closely resembles an ideal gas at standard temperature and pressure (STP) due to its small molecular size and negligible intermolecular forces.