Practical Chemistry Flashcards
What is a standard solution?
a solution whose conc is accurately known
What is a titre?
the required volume delivered from the burette
What is the nearest measurement a burette reads to?
0.05cm3
How do you ensure all water is removed from a thermal decomp expt?
heat to a constant mass
Why is a reful reaction used?
allows prolonged heating without loosing material through evapouration
What is an advantage of using a water bath rather than a bunsen burner?
better control - heating at a constant temp can be acheived
What are distillations used for?
used to purify organic liquids based on different BP
How do you test for Br2?
alkenes and phenols will decolourise Br2
What colour are phenols when universal indicator is added?
red- orange
What happens when you add sodium carbonate to a phenol and a carboxylic acid?
carboxyl = fizzes
phenol= nothing
What happens when you add warm tollen’s reagent to aldehydes?
aldehyde gives a silver mirror
What happens when you add warm acidic potassium dichromate to alcohols and aldehydes?
solution turns from orange to green
