1. To make the following saline solution (375ml 0.5% w/v sodium chloride) what would you weigh out?
What volume of water would you use?
0.5% w/v NaCl means 0.5 g NaCl/100 mL soln.
If you want 375 mL soln instead of 100 mL soln, just proportion it up.
0.5 g x (375/100) = ? g NaCl in 375 mL solution.
I would like to know what volume of water you use?
How to calculate the volume of water?
To make the saline solution of 375ml with 0.5% w/v (weight/volume) sodium chloride, we need to determine the weight of sodium chloride and the volume of water required.
First, let's calculate the weight of sodium chloride needed:
1% w/v sodium chloride solution means that there is 1g of sodium chloride dissolved in 100ml of water. Since we want a 0.5% w/v solution, we need half the amount of sodium chloride.
Weight of sodium chloride needed = 0.5% x 375ml = 0.005 x 375g = 1.875g
So, you would weigh out 1.875 grams of sodium chloride.
Next, let's determine the volume of water needed:
We know that the total volume of the solution is 375ml, and we have already accounted for the weight of sodium chloride. Therefore, the remaining volume will be water.
Volume of water needed = Total volume - Volume of sodium chloride = 375ml - 0ml (since sodium chloride does not contribute to the volume)
So, you would use 375ml of water to make the saline solution.
In summary, to make the saline solution with 375ml at 0.5% w/v sodium chloride, you would weigh out 1.875 grams of sodium chloride and use 375ml of water.