Chem Qs Help

Take Your Pants Off

Can I get some help in this qs.
A group of students carried out an experiment to measure the amount of water crystallisation in a sample of hydrated sodium carbonate crystals. They first accureately weighted out 4.0g of the sodium carbonate crystals and made it up to 250cm cubred in a volumetric flask with distilled water. This soloution was titrated in 25cm cubed portions against a 0.15M hydrochloric acid solution.

Describe the correct procedure for preparing and using a pipette to place 25cmcubred of the sol. into a conical flask.

All I can think of is ''wash out the pipette,burette and conical flask with deionised water''

2nd question is:
A group of students prepared ethanal in the lab by slow addition of an aqueous solution of ethanol and sodium dichromate to a hot solution of sulfuric acid. The apparatus was set up as showin in diagram.

What experiment and page number is this on the Chemistry Live book. I cannot seem to find it...?

Corkgirl18

''Describe the correct procedure for preparing and using a pipette to place 25cmcubred of the sol. into a conical flask.''

The marking schemes for these type of questions are very specific. I'd advise you to study them closely.
I would say wash out the pipette with deionised water, then wash it out with the solution it is to contain. Pour some solution into a beaker. Using the pipette and filler fill the pipette with the solution and read the graduation mark at eye level. Tap the pipette against the beaker. Release the solution into a clean conical flask being careful not to expel the last drop.
Full marks!

The ethanal experiment is pg 425

Gryffindor

Take Your Pants Off wrote: »

A group of students prepared ethanal in the lab by slow addition of an aqueous solution of ethanol and sodium dichromate to a hot solution of sulfuric acid. The apparatus was set up as showin in diagram.

What experiment and page number is this on the Chemistry Live book. I cannot seem to find it...?

I'm almost positive that the preparation of ethanal not been removed from the course due to it involving chromium(VI) solution?
All that is now required is knowledge of the properties.
Look at the amendments to the syllabus below.

curriculumonline.ie/Curriculum/files/7b/7b6ba389-c779-4b17-a6a9-e26534f12a39.pdf

dazzadazza

Gryffindor wrote: »

I'm almost positive that the preparation of ethanal not been removed from the course due to it involving chromium(VI) solution?
All that is now required is knowledge of the properties.
Look at the amendments to the syllabus below.

curriculumonline.ie/Curriculum/files/7b/7b6ba389-c779-4b17-a6a9-e26534f12a39.pdf

Where can I actually find the new experiments to study them?

Mahmoudsaid_1

Preparation of ethanal has been removed now