How many moles of HCl are present in 75.0 mL of a 0.200 M
solution?

0.015 mol HCL

Explanation:

Molarity = moles solute/liters solution

Step 1: Define variables

M = 0.200

L = 75.0 mL

m = unknown, x

Step 2: Convert mL to L

1000 mL = 1 L

75.0 mL/1000 mL = 0.075 L

Step 3: Substitute

0.200 M = x mol/0.075 L

Step 4: Find x

x = 0.015 mol HCL

c-14 is carbon-14, or radiocarbon.   it is a radioactive isotope of carbon with an atomic nucleus containing 6 protons and 8 neutrons.