(H2O) which means 2 hydrogen atoms and 1 oxygen
mol CaCl₂ = 1.2 x 10²⁴ : 6.02 x 10²³ = 1.993
mass = 1.993 x 111 g/mol = 221.223 g
The composition of a compound does not vary because it is made up of fix ratio by mass.
<h3>What is compound?</h3>
A compound is a chemical substance that is composed of more than one element that held together by chemical bonds and produces fix ratio by mass so we can conclude that the composition of a compound does not vary because it is made up of fix ratio by mass.
Learn more about compound here: brainly.com/question/634206
For combustion reaction we need oxygen and the results most of the time produce heat which mean first one is correct.
