Step-by-step explanation:
NaCl is a strong salt of strong base and strong acid whereas HCl is a strong acid.
In the solution both dissociates in the solution into their respective ions as shown below:
NaCl ⇒ Na⁺ + Cl⁻
HCl ⇒ H⁺ + Cl⁻
Hence, the ions Na⁺, Cl⁻ and H⁺ are formed and there is no scope of reaction between them for a gas to evolve. They remain in the hydrated state in water.