Key Chemsitry Facts To Know Flashcards
What is corrosion
The exposure of metals to oxygen, creating a layer of metal oxide
How to work out the number of atoms of an element from its mass and relative atomic mass
- Work out number of moles using n = m/mr
- multiply no of moles by Avogadro’s number (6.02 * 10^23)
If a question asks you to design a test for something what two things do you need to describe?
The steps of the experiment and the observations of what should happen
When measuring the mass of electrodes what two steps do you need to take?
Rinse and dry the electrodes
Weigh the mass, using a mass balance
Why can’t sodium be an electrode
Because it would react with the ions in the solution to form an ionic compound
When measuring a titration what do you need to include?
Write the answer to as many possible figures, eg : 23.60 NOT 23.6
How can you tell in the copper oxide and sulphuric acid when no more copper oxide needs to be added
The copper oxide stops fizzing, copper sulphate solution stops changing color and there is excess copper oxide as there is lots of black powder left in the bottom
What happens if a burrette was rinsed and not dried how will it if at all affect the titre volume
There will be no change
Ways to make a titration better
Do a rough titration and measure it to there and then do it drop by drop
Don’t overfill burrette
Wash out the burrette and dry it
What color is a lithium ion flame
Red/crimson
What color is a sodium ion flame
Yellow
What color is a potassium ion flame
Lilac
What color is a calcium ion flame
Brick red
What color is a copper ion flame
Blue/green
What happens to copper as it burns in oxygen?
Turns black slowly as it’s covered in a black layer of copper oxide
What happens to magnesium as it burns in oxygen?
Bright white flame burns , white solid is formed
What happens to calcium as it burns in oxygen?
Burns with a bright red flame, white solid formed
What happens to zinc powder as it burns in oxygen?
A bluefish flame is burned, and a white solid is formed
What happens to potassium as it burns in oxygen?
Burns with a lilac flame, white solid is formed
What happens to iron filings as it burns in oxygen?
Burns with an orange/yellow flame, a brown solid forms (Fe2O3)
Which metals react with acids to form H2
Ca, Mg, Al, Zn and Fe
Which metals don’t react with dilute acids
Copper, silver, gold and platinum
Which metals react with steam but not water
Aluminum, zinc, and iron
Which metals don’t react with water (or steam)
Tin, lead, copper, silver, gold and platinum