environmantal

1) If the total area of the clarifier is 25,000 m2 and the L/W = 5, what is the width of the clarifier?
a) 5000 m
b) 71 m
c) 158 m
d) 355 m

2) The molecular weight of orthophosphate (PO43-) is 95 g/mole and the concentration is 20 mg/L. What is the concentration in meq/L?
a) 9.5 meq/L
b) 14.25 meq/L
c) 20 meq/L
d) 4.75 meq/L

3) At a pOH = 11.5, the [H+] =
3.16 x 10-11 mg/L
0.0316 mg/L
31.6 mg/L
3.16 x 10-8 mg/L

4) At neutral pH (around 7), the biggest contribution to alkalinity is:
hydroxide
carbonic acid
carbonate
bicarbonate

5) A sample of water has a calcium concentration of 1.2 meq/L and a magnesium concentration of 0.3 meq/L. The total hardness in mg/L as CaCO3 is:
75 mg/L as CaCO3
1.5 mg/L as CaCO3
60 mg/L as CaCO3
15 mg/L as CaCO3