Here's how to calculate the alkalinity and arrive at the solution:

Understanding Alkalinity

Alkalinity is the capacity of water to neutralize acids. In most natural waters, it's primarily due to the presence of bicarbonate (HCO₃⁻), carbonate (CO₃²⁻), and hydroxide (OH⁻) ions. Since the pH is close to 7.0, we can assume that bicarbonate (HCO₃⁻) is the dominant contributor to alkalinity.

Calculation Steps

1. Convert HCO₃⁻ concentration from mg/L to meq/L (milliequivalents per liter):

   • Molar mass of HCO₃⁻: 1 (H) + 12 (C) + 3 * 16 (O) = 61 g/mol
   • Equivalent weight of HCO₃⁻: Since HCO₃⁻ has a charge of -1, its equivalent weight is equal to its molar mass: 61 g/eq
   • meq/L of HCO₃⁻: (160.0 mg/L) / (61000 mg/eq) = 0.002623 eq/L 0.002623 eq/L * 1000 meq/eq = 2.623 meq/L

2. **Convert meq