Producing a standard solution, Jan 08 planning question.

How do you go about it, I have really forgotten, I know you add a known amount of substance to a known amount of water and then you have a standard solution, but other than that Im stuck. Any help would be appreciated

Reply 1

Excalibur

- Weigh an exact known mass of solid on a weighing boat (using the tare button, or alternatively, weighing the mass & boat, then substracting the mass of the boat afterwards).

- Rinse all equipment with distilled water.

- Using a sawn off funnel put the solid into a volumetric flask. Rinse the weighing boat and the funnel to make sure every last bit of solid goes in.

- Add water to about halfway up the flask, put the stopper on and shake until the solid is completely dissolved. (If you are worried about the solid not dissolving well in this method, you can dissolve the solid in a beaker first before you add to the volumetric flask. In this case make sure you rinse the beaker too)

- Fill with distilled water until the 250cm3 mark. When nearing the mark use a small dropper until the line is just above the meniscus.

- Put the stopper on and invert the volumetric flask a few times to ensure a thorough mix.

Hope that helps.

Reply 2