Question

A fuel scientist burnt a piece of coal and a piece of wood to compare the amount of heat given off by each. Which is the correct match of the type of change happening and the property being tested during the process?
Physical change; Chemical property flammability

Physical change; Physical property of flammability

Chemical change; Physical property of heat of combustion

Chemical change; Chemical property of heat of combustion

Answer 1

Answer: Chemical change; Chemical property of heat of combustion

Explanation:

A physical change is defined as a change in which there is alteration in shape, size etc. No new substance gets formed in these reactions.

Example: Melting of ice

Physical property is defined as the property of a substance which becomes evident during physical changes. Example: Melting point

A chemical change is defined as a change in which a change in chemical composition takes place. A new substance is formed in these reactions.

Example: combustion

$C+O_2\rightarrow CO_2$

Chemical property is defined as the property of a substance which becomes evident during chemical changes. Example: Reactivity with other substances

Thus when a piece of coal and a piece of wood is burnt , there is formation of new substances and thus is a chemical change. Combustion is a chemical property as it is reactivity of a substance with oxygen.

Answer 2

The answer is a since its a physical to chemical change