Question

When hydrogen is replaced by another element in a hydrocarbon, the reaction is called: addition substitution hydrogenation combustion

Answer 1

Substitution.... I think.

Answer 2

Answer:substitution

Explanation:

Addition reaction is defined as the reaction in which two reactants get added to give single product.

$CH_2=CH_2+H_2\rightarrow CH_3CH_3$

Substitution reaction is defined as the reaction in which one atom replaces the other atom from the compound.

$CH_4+Cl_2\rightarrow CH_3Cl+HCl$

Hydrogenation is addition of hydrogen to unsaturated hydrocarbons.

$CH_2=CH_2+H_2\xrightarrow[]{hydrogenation} CH_3CH_3$

Combustion is a type of chemical reaction in which fuel is reacted with oxygen to form carbon dioxide and water.

Example:  $C_6H_{12}O_6+O_2 \rightarrow CO_2+H_2O$