Which of the following is a chemical property? freezing point color ability to react with oxygen hardness

Option (c) is the correct answer.

Explanation:

A property which does not bring any change in chemical composition of a substance are known as physical properties.

For example, shape, size, mass, volume, density, etc of a substance are all physical properties.

And, a property that changes chemical composition of a substance is known as chemical property.

For example, precipitation, reactivity, toxicity etc are chemical property.

Therefore, ability to react with oxygen also depicts its chemical property.

Thus, we can conclude that out of the given options ability to react with oxygen is a chemical property.

the equation that correctly represent the reaction for formation of ammonia is

n2+ 3h2 → 2nh3 (answer d)

1 mole of nitrogen gas (n2) react with 3 moles of hydrogen gas (h2) to form 2 moles of ammonia ( nh3). this is in a process known as haber process were iron is used as a catalyst and reaction take place that a higher temperature and pressure. the process is exothermic hence energy is released.