When water is heated a physical change occurs and it forms steam. When a lighted splint is applied to hydrogen gas, a chemical change occurs producing water in the form of steam. Explain how these two statements show two differences between physical and chemical changes.

Answer:

- A new substance was formed in the chemical change while no be substance was formed in the physical change

- The chemical change involved a change in chemical composition while the physical change involved no change in chemical composition

Please find the explanation below.

Explanation:

A physical change is a change that does not alter the chemical content of the substances involved, hence, no new substances are produced while a chemical change alters the chemical composition, hence, new substances results.

In this question,

- Water is heated till it forms steam is characterized as a physical change

- Lighted splint is applied to hydrogen gas to produce water in the form of steam is characterized as a chemical change.

- The first process is a PHYSICAL CHANGE because it involved only a change of state i.e. from liquid to gas, hence, no alteration to the chemical composition of the molecule and also no new substance is produced.

- The second process is a CHEMICAL CHANGE because there was a chemical combination of hydrogen gas and the oxygen in the lighted splint to yield water molecules ( a new substance). Therefore, it involved a chemical reaction and formation of a new substance

Which formula compares a sample of a gas under two different conditions of pressure and volume, if the temperature is constant?

⚪︎ x/y = k
⚪︎ xy = k
⚪︎ PV = k
⚪︎ V/T = k
⚪︎ P1V1 = P2V2