How do I get the answer for NaBr+H3PO4

Na₃PO₄ + HBr

Explanation:

To find the product of the reactants NaBr + H₃PO₄ decide what type of reaction it would likely be.

There are four elements, so it would be double displacement (where each element/polyatomic ion changes its partner). Since the reactions are not an acid (begins with H) and a base (ends with OH), it is not neutralization.

Identify what type of elements/polyatomics they are:

In NaBr, Na is metal and Br is non-metal.

In H₃PO₄, H is a metal and PO₄ is a non-metal.

Bonds only form between two non-metals, or between a non-metal and a metal; it's never metal + metal.

NaBr + H₃PO₄ = > NaPO₄ + HBr

Here, the non-metals switched places to form new bonds.

Fix the number of atoms:

In each of the products, use the "criss-cross" rule, where each element has the same number of atoms as its partner's charge.

Put brackets around polyatomic ions, in this case PO₄ phosphate.

NaBr + H₃PO₄ = > Na (PO₄) + HBr

Since (PO₄) has a charge of - 3, which you can find on your polyatomic ions charts, its partner Na will get 3 atoms.

Since Na has a charge of + 1, PO₄ gets 1 atom.

Bromide has a charge of - 1, so hydrogen gets 1 atom.

NaBr + H₃PO₄ = > Na₃ (PO₄) ₁ + H₁Br₁

Remove the brackets and any ₁ subscripts.

NaBr + H₃PO₄ = > Na₃PO₄ + HBr