Consider the equation: ca+o2→cao what needs to be done in order to balance the equation? a place a 2 in front of the o2 and the cao . b place a 2 in front of the cao only. c place a 2 only in front of the ca . d place a 2 in front of the ca and the cao .

D

Explanation:

I took this class last year seems right

Answer : The correct option is, (D) Place a 2 in front of the Ca and the CaO.

Explanation :

Balanced chemical reaction : It is defined as the number of atoms of individual elements present on reactant side must be equal to the product side.

The given unbalanced chemical reaction is,

This chemical reaction is an unbalanced reaction because in this reaction, the number of atoms of oxygen are not balanced while all the atoms are balanced.

In order to balanced the chemical reaction, the coefficient 2 is put before the 'Ca' and 'CaO'.

Thus, the balanced chemical reaction will be,

Hence, the correct option is (D) Place a 2 in front of the Ca and the CaO.

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.