Preparation of solutions

1M Citric acid solution

1. Citric acid in powder form is kept in the cleanroom hallway.
2. Citric acid is solution is kept in dedicated bottles in CR1 cupboard(by the spin coater)

Preparation of the bottle

1. Clean the bottle with MQ water, multiple times
2. Take 1L MQ water in this bottle
3. Keep the bottle on Hot plate @ 85deg
4. Keep magnetic stirrer running
5. Take 193gm of Citric acid powder by using weighing balance accurately. (This is very important to weigh accurately. If the MQ water volume is changed, the weight of Citric acid also should be changed proportionally.)
6. Add Citric acid powder carefully to MQ water (which is on hot plate)
7. Stir it till the solution becomes a clear transparent one

Please note that we are making 1L solution in a standard 1L glass bottle. As we mix Citric acid to water, the total volume increases and the solution meniscus reach till the neck of the bottle. This is not ideal, though.

Mention the date of preparation on the bottle with the subgroup name.