Answer
20. g of mannitol are given to the patient in 1 hour.
Work Step by Step
1. Identify the conversion factors:
- Since the mannitol solution is 20.% (m/v):
20. g (Solute) = 100 mL (Solution)
So: $\frac{20. \space g \space (Solute)}{100 \space mL \space (Solution)}$ and $\frac{100 \space mL \space (Solution)}{20. \space g \space (Solute)}$
2. Calculate the mass of solute needed to prepare 100. mL of that solution:
$100. \space mL \space (Solution) \times \frac{20. \space g \space (Solute)}{100 \space mL \space (Solution)} = 20. \space g \space (Solute)$
3. One 100. mL solution is given every hour. Therefore, in 1 hour, one 20.% (m/v) mannitol solution is given to the patient, which has 20. g of mannitol.
