Isotonic saline is a 0.9%(g/100ml) solution of salty water. You are asked to make up 2 Litres of isotonic saline. How much salt should you weigh out?
Is this right?
0.9g/100ml * 2000ml = 18g of salt should be weighed out.
It looks good to me.
Yes, your calculation is correct. To make 2 liters of isotonic saline solution, you would need to weigh out 18 grams of salt. Let me explain how this calculation is derived:
First, let's convert the volume from milliliters (ml) to liters (L). We have 2000 ml, which is equivalent to 2 L.
Next, the concentration of isotonic saline is given as 0.9% (g/100ml). This means that for every 100 ml of solution, there are 0.9 grams of salt.
To calculate the amount of salt needed for 2 liters of solution, we can set up a proportion:
0.9 grams/100 ml = x grams/2000 ml
Cross-multiplying, we get:
100 ml * x grams = 0.9 grams * 2000 ml
Simplifying the equation:
100x = 1800
Dividing both sides by 100:
x = 18
Therefore, you would need to weigh out 18 grams of salt to make 2 liters of isotonic saline solution.