I got stuck on a silly easy question, and have a test soon. Was hoping someone could assist me.
I need to calculate the pH of a solution containing 2g of NaNO2 in 500ml. I know the Kb.
I know I need to solve it with one of the formulas:
H+=(Ka X Ca)^0.5
HO-= (Kb X Cb)^0.5
I know I can calculate the Ka since I know the Kb (pKa+pKb=pKw=14)
My problem is:
I calculated the concentration of NaNO2 (2g/mw/2). I don't understand how do I tell if this is Ca or Cb...