A compound. Specifically an ionic compound
In this solution we are having two components i.e. NaCl and H₂O. So the %age mass of NaCl is calculated by following formula,
%age mass of NaCl = (Mass of NaCl / Mass of NaCl + Mass of H₂O) × 100 ------ (1)
Calculating Mass of NaCl at 50°C;
Solubility of NaCl was searched online and was found 36.69 g / 100 mL of water at 50 °C.
Calculating Mass of 100 mL H₂O at 50°C;
Density of H₂O at 50 °C is 0.988 g/ml, so for 100 mL
As,
Density = Mass / Volume
Mass = Density × Volume
Mass = 0.988 g/mL × 100 mL
Mass = 98.8 g
Putting Masses of NaCl and H₂O in eq. 1,
%age mass of NaCl = (36.69 g / 36.69 g + 98.8 g) × 100
%age mass of NaCl = (36.69 g / 135.49 g) × 100
%age mass of NaCl = 27.07 %
Answer:
B. Secondary pollutant
Explanation:
A primary pollutant is directly emitted into the atmosphere. Volcano eruptions and emissions from cars can result in primary pollutants in the air.
Secondary pollutants are not directly put in the atmosphere. They are created when two or more primary pollutants in the atmosphere react. One example is smog.
Another example is acid rain. If sulphur dioxide, nitrogen dioxide and water react, then acid rain is formed. Therefore, acid rain must be a secondary pollutant.
The best answer choice is B. secondary pollutant
