Question

A 93 L batch of Ropivacaine is being made. The specific gravity is 1.01 g/mL. 196.42 g of Ropivacaine and 799.8g of sodium chloride are added. What is the weight of the water to be added to QS the solution?

Answer 1

92.93378 kg

Explanation:

Given that:

Volume of Batch = 93 L

= 93 × 1000 (since 1 L = 1000 mL)

= 93000 mL

Specific gravity =
`(density \ of \ solution)/(density \ of \ water)`

where;

density of water = 1 g/ml

specific gravity = 1.01 g/mL

Density of solution = (1.01 × 1) g/mL

Density of solution = 1.01 g/mL

`Density \ of \ solution = (mass \ of \ batch )/(volume \ of \ batch)`

mass of batch = 1..01 g/mL × 93000 mL

mass of batch = 93930 g

Now, the mass of additional water = mass of (batch - Ropivaciance - sodium chloride)

= 93930 g - 196.42 g - 799.8 g

= 92933.78 g

Since 1kg = 1000 g

The weight of the water to be added to the QS solution is:

`=(92933.78)/(1000)`

= 92.93378 kg