Making standard solution (1 Viewer)

[leesh95]

At school we are making a standard solution of oxalic acid and using it to titrate NaOH.

I made mine in a volumetric flask and made it up to the mark; then I transferred my solution from the flask into a bottle using a funnel. Unfortunately the funnel was slightly wet and when transferring the solution to the bottle, a couple of water droplets in the funnel mixed with my solution.

Now I am worried that my volume changed thus changing the concentration. Is it better to start again all together or am I being paranoid and a few droplets make no difference?

 

[someth1ng]

At school we are making a standard solution of oxalic acid and using it to titrate NaOH.

I made mine in a volumetric flask and made it up to the mark; then I transferred my solution from the flask into a bottle using a funnel. Unfortunately the funnel was slightly wet and when transferring the solution to the bottle, a couple of water droplets in the funnel mixed with my solution.

Now I am worried that my volume changed thus changing the concentration. Is it better to start again all together or am I being paranoid and a few droplets make no difference?

You should have rinsed the funnel with the standard solution before transferring to the bottle. It is no longer a primary standard and so, you are supposed to start again.

With that said, it is a school experiment and you can afford some inaccuracy but when reciting the method, make sure you include the rinsing with the primary standard step.