To find the milliosmols (mOsm) of K⁺ ions in a liter of solution, we can go through these steps:

Step 1: Convert 312 mg of K⁺ per 100 mL to mg per liter

Since 1 liter is 1000 mL, we can scale up the concentration: $312 \text{ mg} \times \frac{1000 \text{ mL}}{100 \text{ mL}} = 3120 \text{ mg/L}$

Step 2: Convert mg/L of K⁺ to moles/L (Molarity)

The molar mass of potassium (K⁺) is approximately 39.1 g/mol. Convert mg/L to moles/L as follows: $3120 \text{ mg/L} \times \frac{1 \text{ g}}{1000 \text{ mg}} \times \frac{1 \text{ mol}}{39.1 \text{ g}} = 0.0798 \text{ mol/L}$

Step 3: Calculate milliosmols (mOsm/L)

Since K⁺ is a monovalent ion (each K⁺ ion contributes 1 particle), the osmolarity (mOsm/L) is equal to the molarity (in mol/L) multiplied by 1000 (to convert to milliosmols): $0.0798 \text{ mol/L} \times 1000 = 79.8 \text{ mOsm/L}$

Answer

There are approximately 79.8 milliosmols (mOsm) of K⁺ ions in a liter of solution.

Would you like further clarification on any step?

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Related Questions:

1. How would you calculate the milliosmolarity if there were multiple ions in the solution?
2. What would happen to the osmolarity if the K⁺ concentration were halved?
3. How would this calculation change if the ion were divalent, like Ca²⁺?
4. How does osmolarity relate to osmotic pressure in a solution?
5. Why do we multiply by 1000 to convert molarity to milliosmolarity?

Tip: Always check the valency of ions when calculating osmolarity, as each ion contributes particles according to its charge.