List-I (Species) | List-II (Maximum allowed concentration in ppm in drinking water) | ||
A | F- | I | < 50 ppm |
B | \(SO^{2-}_4\) | II | < 5 ppm |
C | \(NO^-_3\) | III | < 2 ppm |
D | Zn | IV | < 500 ppm |
Choose the correct answer from the options given below :
Solute A associates in water. When 0.7 g of solute A is dissolved in 42.0 gof water, it depresses the freezing point by 0.2°C. The percentage association of solute A in water is :
[Given : Molar mass of A = 93 g mol–1. Molal depression constant of water is 1.86 K kg mol–1.]
The portion of the line \( 4x + 5y = 20 \) in the first quadrant is trisected by the lines \( L_1 \) and \( L_2 \) passing through the origin. The tangent of an angle between the lines \( L_1 \) and \( L_2 \) is: