The average adult human male has a total blood volume of 5.0 L. If the concentration of sodium ion in this average individual is 0.135 M, what is the mass of sodium ion circulating in the blood?

Verified step by step guidance

1. Step 1: Identify the given values in the problem. The total blood volume is 5.0 L, and the concentration of sodium ion (Na^+) is 0.135 M (moles per liter).
2. Step 2: Use the formula for molarity, which is M = \frac{n}{V}, where M is the molarity, n is the number of moles, and V is the volume in liters. Rearrange this formula to solve for the number of moles: n = M \times V.
3. Step 3: Substitute the given values into the rearranged formula to calculate the number of moles of sodium ion: n = 0.135 \text{ M} \times 5.0 \text{ L}.
4. Step 4: Calculate the molar mass of sodium ion (Na^+). The atomic mass of sodium (Na) is approximately 22.99 g/mol.
5. Step 5: Use the number of moles calculated in Step 3 and the molar mass from Step 4 to find the mass of sodium ion: \text{mass} = n \times \text{molar mass of Na^+}.

Key Concepts

Molarity (M)

Molarity is a measure of concentration defined as the number of moles of solute per liter of solution. It is expressed in moles per liter (mol/L) and is crucial for calculating the amount of a substance in a given volume. In this question, the sodium ion concentration is given as 0.135 M, indicating that there are 0.135 moles of sodium ions in every liter of blood.

Total Volume

Total volume refers to the amount of space occupied by a substance, in this case, the total blood volume of an average adult male, which is 5.0 L. This volume is essential for determining the total amount of sodium ions present in the blood by multiplying the concentration (in moles per liter) by the total volume (in liters).

Molar Mass

Molar mass is the mass of one mole of a substance, typically expressed in grams per mole (g/mol). For sodium ions (Na+), the molar mass is approximately 23 g/mol. To find the mass of sodium ions in the blood, the number of moles (calculated from molarity and volume) is multiplied by the molar mass, providing the total mass of sodium circulating in the bloodstream.