Determine the relative humidity of the air if, at a temperature of +10 ° C, 1 m1 of this air contains 1 g of water vapor

Relative air humidity φ is equal to the ratio of absolute air humidity ρ and saturated vapor density ρо (at the same temperature). That is, it is determined by the formula: φ = ρ / ρо. From the conditions of the task it is known that 1 m³ of atmospheric air contains 1 g of water vapor at a temperature of + 10 ° C, which means ρ = 1 g / m³. From the reference tables we find that the density of saturated steam at a temperature of + 10 ° C is equal to ρо = 9.4 g / m³, respectively. We substitute the found values ​​of physical quantities into the formula and perform the calculations, we obtain the relative humidity of the air φ = 1 / 9.4 ≈ 0.106 = 10.6%.
Answer: the relative humidity of this air is 10.6%.