Question

What is the concentration of N2(g), in

parts per billion, in a solution that
contains 1.5 * 10 ^ - 6 g of N2(g) dissolved
in 7.5 g of H2O(l)?
Can someone tell me why 200 is the right answer?

Answer 1

The concentration of N2(g) in parts per billion (ppb) in a solution can be calculated as follows:

(mass of N2(g) in solution / total mass of solution) * 10^9 ppb

Plugging in the given values, we have:

(1.5 * 10^-6 g / (7.5 g + 1.5 * 10^-6 g)) * 10^9 ppb = (1.5 * 10^-6 g / 7.5 g) * 10^9 ppb = 200 ppb

So, the concentration of N2(g) in the solution is 200 ppb.