Sally carries out the following chemical reaction in an open container. MnO2 (s) + 4HCl (aq) MnCl2 (aq) + 2H2O (l) + Cl2 (g)

She finds that the total measured mass of the products is less than the mass of the reactants. How can she best explain this difference in mass between the products and reactants?

1Mass was not actually conserved in this reaction

2Because the products are all liquid or gas, they cannot be measured accurately

3The water formed in the reaction made up the mass of the chlorine gas that was released

4Some of the mass in the product was converted into gas, which was released into the air

4

Explanation:

the electronic configuration of an atom with eight electrons is 1s²2s²2p⁴. the orbital diagrams are shown in the figure.

as per the hunds rule:

1. electrons tend to avoid being in the same orbital as per as practicable.

2. electrons in different orbitals of the same energy will have their spin parallel.

this can be illustrated from the multiplicity of the orbitals of the atom. as there are four electrons in the p orbital and p orbital has 3 sub-shells. the electrons can be fed in different ways as shown in the figure but the correct orbital diagram will be as per the hunds rule.

the answer is barium and copper bromide