You need to make 50 agar plates. Each plate holds 30mls. Final agar concentration is 2.5%. How much agar powder to you need?
To determine how much agar powder you need, you need to calculate the total volume of agar solution required for 50 agar plates and then calculate the amount of agar powder needed to prepare that volume.
Step 1: Calculate the total volume of agar solution needed
Since each plate holds 30ml, we can multiply the number of plates (50) by the volume per plate (30ml) to find the total volume:
Total volume = 50 plates × 30ml/plate = 1500ml
Step 2: Calculate the agar weight needed
The agar concentration is given as 2.5%. This means that for every 100ml of agar solution, 2.5g of agar powder is needed. We can set up a proportion to find the agar weight for the total volume:
(2.5g / 100ml) = (x / 1500ml)
Cross-multiplying, we get:
2.5g × 1500ml = 100ml × x
3750g-ml = 100ml × x
Simplifying, we find:
3750g = 100x
x = 3750g / 100
x = 37.5g
Therefore, you would need approximately 37.5 grams of agar powder to prepare 50 agar plates, each with a volume of 30ml and a final agar concentration of 2.5%.