Extra Flashcards
What is the colour change when chlorine gas in bubbled into sodium bromide?
Colourless to orange
Ionic equation for neutralisation?
H+ (aq) + OH- (aq) -> H2O (l)
How would you obtain pure dry copper sulphate crystals from filtrate of copper oxide + sulphuric acid. (Excess copper oxide has Been filtered off)
Evaporate filtrate to half volume.
Allow to cool and crystallise
Dry between 2 pieces of paper
What colour is aluminium hydroxide?
White
Observations when calcium carbonate + hydrochloric acid?
Heat released
Disappears
Colourless solution formed
Chemical test for aluminium ions?
Validity?
Add NaOH, white precipitate forms.
Add excess, precipitate redissolves.
Zinc ions give same result.
What is an element?
Cannot be broken down by chemical means.
Pure substance made up of only 1 type of atom.
What is an allotrope?
Different structure of same element in the same physical state.
How would the results change if you kept the same mass of a metal but used powder instead of ribbon?
Faster reaction and steeper slope.
Finishes at same gas volume.
Why does calcium oxide have a high melting point?
Strong ionic bonds between calcium and oxide ions which require lots of energy to break.
Write a balanced symbol equation for the reaction between calcium oxide and water.
CaO + 2H2O -> Ca(OH)2
Are these reactions endothermic or exothermic?
- Combustion, Photosynthesis, Condensation, Freezing and Neutralisation.
Exothermic, Endothermic, Exothermic, Exothermic and Exothermic.
State the colour change when copper (ii) carbonate is heated.
Green to black
What is the line at the top of chromatography paper called?
Solvent front
What label should be placed on the bottom of an HPLC graph?
Retention time
Why do covalently bonded compounds only conduct electricity when molten?
When molten the ions can move and carry charge
Why does chlorine have a low melting point?
Little energy required to break the Weak Van der Waals’ forces between chlorine molecules
Why does graphite conduct electricity?
Delocalised electrons can move and carry charge
What is the structure of diamond?
Each carbon atom covalently bonded to 4 other carbon atoms in a tetrahedral structure
