Question

When a solution of barium hydroxide reacts with a solution of phosphorous acid, the product are water liquid and aqueous solution of barium phosphite. Keeping this order, what are the set of coefficients of the balanced neutralization?

Select one:

A. 3-2-6-1

B. 3-2-6-2

C. 1-1-1-1

D. 3-2-3-1

Answer 1

The answer is the A.

Here is the reaction of neutralization that they are telling us.

Ba(OH)2 + H3PO4 ========= H2O + Ba3(PO3)2

See that hte barium has 1 aotm in the reactant side and 3 in the other, so we have to put a 3 in the reactants.

3 Ba(OH)2 + H3PO4 ========= H2O + Ba3(PO3)2

Now we have 1 aotm of P in the reactants and 2 int the products, so we have to add the 2 in the reactants.

3 Ba(OH)2 + 2 H3PO3 ========= H2O + Ba3(PO3)2

We now have 6 oxigens from the hydroxide barium, 6 atoms from phosphoric acid in the reactants and 6 from the barium phosphite and 1 from the water. So we have 14 oxygen atoms in the reactants and 6 on the products, so we add 6 to the products.

3 Ba(OH)2 + 2 H3PO3 ========= 6 H2O + Ba3(PO3)2

Now we check if the hydrogens atoms are balanced: we have 12 in the reactants side and 12 in the products side so the equation is balance.

The only answer possible is the A. 3 - 2 - 6 - 1.