Sodium chloride reacts with phosphoric acid to form sodium phosphate and hydrochloric acid. Answer in a balanced chemical equation.

  3NaCl   +    H₃PO₄  →    Na₃PO₄   +  3HCl

Explanation:

The reactants in this reaction are:

       Sodium chloride  -    NaCl

        Phosphoric acid   -  H₃PO₄

Products of the reaction:

        Sodium phosphate  - Na₃PO₄

         Hydrochloric acid    - HCl

Therefore;

            NaCl   +    H₃PO₄  →    Na₃PO₄   +  HCl

To balance this reaction expression, assign variables a,b, c and d to it;

   aNaCl   +    bH₃PO₄  →    cNa₃PO₄   +  dHCl

Conserving Na;  a  = 3c

                    Cl;   a  = d

                     H;   3b  = d

                     P;   b  = c

                    O;   4b  = 4c

let c  = 1, b  = 1, a  = 3 and d = 3

So;

      3NaCl   +    H₃PO₄  →    Na₃PO₄   +  3HCl

calculate how many grams of ammonia can be produced from 4.21 grams of

n2 + 3h2 = 2nh3

my answer:

25.0g n2 x (1 mol/ 28.0gn2) x (2 mol nh3/ 1 mol n2) x (17.0g nh3/ 1 molnh3) = 30.36g n2

25.0g h2 x (1 mol h2/ 2.00g h2) x (2 mol nh3/ 3 mol h2) x (17.0g nh3/ 1 mol nh3) = 141.67g h2

lr = n2

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.