Question

Which of the following is/are conserved in a chemical reaction?

1. moles of compounds (ex. If there are 4 moles of reactants, there must be 4 moles of products)

2. mass (ex. If the reactants have a total mass of 65 grams, then the products must have total of 65 grams)

3. number of each type of atom (if there are 6 atoms of H on the product side, there must be 6 atoms of H on the reactant side)

a. 1 only

b. 2 only​

c. 1 and 2 only

d. 2 and 3 only

Answer 1

answer : d.) 2 and 3 only

explanation:

in chemical reaction . total mass is conserved and total atoms conserved

example :

2 H2 + O2 ----------------> 2 H2O

4 g        32g                         36g

reactants total mass = 4 + 32 = 36

products mass = 36 g

number of atoms in reactants = number of atoms in products