Which of the statements correctly describes the relationship between pressure (P) and volume (V) illustrated in the plot for a gas at constant temperature? a. The pressure of a fixed amount of gas is inversely proportional to its volume.
b. The pressure of a fixed amount of gas is directly proportional to the inverse of its volume.
c. The pressure of a fixed amount of gas is directly proportional to its volume.

a. The pressure of a fixed amount of gas is inversely proportional to its volume.

Explanation:

At constant temperature, the relationship between pressure (P) and volume (V) illustrated in the plot for a gas gives a straight line from the origin.

This relationship was described by a law stated by Robert Boyle, an English Chemist, in 1662.

Boyle's law states that the pressure of a fixed mass of gas is inversely proportional to the volume, provided the temperature remains constant.

The relationship for Boyle’s Law can be expressed mathematically as follows:

P1V1 = P2V2; where P1 and V1 are the values of the initial pressure and volume, and P2 and V2 are the final values of the pressure and volume of the gas.

the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.