Question

which of the following equations is correctly represented by the word description given below?
solid sodium metal reacted violently with water producing heat. the products of the reaction were a water solution of sodium hydroxide and hydrogen gas.
2na(s) + h₂o(l) → na₂oh(aq) + h₂(g)
na₂(s) + h₂o(aq) → na₂oh(aq) + 2h(g)
2na(s) + h₂o(l) → 2naoh(aq) + 2h(g)
2na(s) + 2h₂o(l) → 2naoh(aq) + h₂(g)
2na(s) + h₂o(aq) → na₂oh(aq) + 2h(g)

Explanation:

Step1: Check the formula of sodium hydroxide

Sodium hydroxide formula is \(NaOH\), not \(Na_2OH\). So first option is wrong.

Step2: Check the state of water

Water in this reaction is liquid (\(l\)), not aqueous (\(aq\)). So second and fifth options are wrong.

Step3: Check the formula of hydrogen gas

Hydrogen gas formula is \(H_2\), not \(2H\). So third option is wrong.

Answer:

\(2Na(s)+2H_2O(l)\to2NaOH(aq)+H_2(g)\) (the fourth option)