Explanation:
An ammonia 
molecule contains electronegative nitrogen atom. The difference between electronegativity of nitrogen and hydrogen atom is high.
Therefore, nitrogen will attract the shared pair of electrons more towards itself. As a result, there will be partial positive charge on hydrogen and partial negative charge on nitrogen.
Thus, due to these charges 
is polar in nature.
Given:
The density of air = 1.19 g/L at 25°C and atmospheric pressure,
or
density = 1.19 x 10⁻³ kg/L
Volume of air in the room is
V = 12.5*19.5*6.0 = 1462.5 ft³
Note that
1 ft³ = 28.317 L
Therefore
V = (1462.5 ft³)*(28.317 L/ft³) = 4.1414 x 10 ⁴ L
By definition, mass = density*volume.
Therefore, the mass is
(1.19 x 10⁻³ kg/L)*(4.1414 x 10⁴ L) = 49.283 kg
Answer: 49.3 kg (nearest tenth)
An acid and a base
For example
Sodium Hydroxide+Hydrochloric acid———Sodium chloride +Water
