Question

Which of the following is a chemical reaction? Check all that apply. Check all that apply. Propane forms a flame and emits heat as it burns. Heat is felt when a warm object is placed in your hand. Acetone feels cold as it evaporates from the skin. Bubbling is observed when potassium carbonate and hydrochloric acid solutions are mixed.

Answer 1

Options A and D

Step-by-step explanation:

A chemical reaction is a process that leads to the chemical transformation of one set of chemical substances to another. Simply put, new elements/ compounds are formed. other characteristics includes;

- Large amount of heat involved.

- Process is not reversible by ordinary physical means.

A. When propane burns, new products (Carbon dioxde, vapour, soot etc) are formed and also heat is involed.

B. This is just the transfer of heat due to the temperature difference.

C. Evaporation is not a chemical reaction rather it is the change in phase; from liquid to gaseous state.

D. When potassium carbonate reacts with hydrochloric acid it vigorously produce carbon dioxide gas, leaving the aqueous state of potassium chloride.

Only options A and D satisifies the conditions. hence they can be regarded as chemical reactions.

Answer 2

The answer to your question is:

Step-by-step explanation:

Propane forms a flame and emits heat as it burns. This is a chemical reaction because propane is transform into CO2 and water.

Heat is felt when a warm object is placed in your hand. THis is not a chemical reaction because matter do not form new compounds.

Acetone feels cold as it evaporates from the skin. This is not a chemical reaction because skin does not convert into new compounds.

Bubbling is observed when potassium carbonate and hydrochloric acid solutions are mixed. This is a chemical reaction because KCO3 reacts with HCl to form KCl.