8. Calculate the molar mass of an alkane with the mole-
cular formula C H18.

Molar mass of CH18 =30

Explanation:

CH18

Molar mass of carbon = 12

Molar mass of hydrogen (H) = 1

CH18 = 12 + 1 (18) = 12 +18 = 30

Molar mass = 30 g/ mole CH18

Explanation: The molar mass of CH18 can be calculated by having the sum of the atomic mass of each atom in the compound.

C - 12 (1 ) = 12

H - 1 ( 18 ) = 18

Molar mass = 30 g / mole CH18

a. energy is absorbed in the reaction.

if in a given reaction the energy of products is greater than the energy of reactants it means that reaction is endothermic and during the reaction, the energy is absorbed by reactants. in an endothermic reaction, the products have more stored chemical energy than the reactants. and in this reaction the reactants are more stable than products before the compounds with less energy are always more stable.