I the total area of the clarifier is 25000 m2 and the lw

Question

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 (PO^43-) 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