The name is Bond, Chemical Bond
What is the formula of beryllium hydroxide? What type of bond is this?
Be(OH)2
This is an ionic bond.
What is the mass of one mole of NaCl?
58
What is the CIE definition for electrolysis?
Chemical breakdown
Ionic Compound
Aqueous or Molten
Passage of electricity
Is freezing exothermic or endothermic?
Exothermic
30s
What is the trend in reactivity of group 7 halogens?
decreases down the group
Explain why the formula for potassium oxide is K2O instead of KO.
If 0.25 moles of carbon dioxide are produced in a reaction, how much space will it occupy in dm3?
What is observed at the anode in the electrolysis of molten sodium chloride?
Bubbles/Green gas/Blue litmus paper bleaches white
(Chlorine gas observations)
H2 + Cl2 --> 2HCl
Is this reaction exothermic or endothermic? Use the bond energies below to help you out.
H--H = 436
Cl--Cl = 242
H--Cl = 431
1 min
Write out the metals in the reactivity series from least reactive to most reactive. Include carbon and hydrogen.
Gold, Silver, Copper, Hydrogen, Iron, Zinc, Carbon, Aluminium, Magnesium, Lithium, Sodium, Potassium
Draw out the bonding in N2
2 free electrons/1 pair of lone electrons.
3 minutes
11.25g of hydrated copper sulfate CuSO4 . xH2O is heated until it loses all of its water. It is reweighed and its mass is 7.19.
What is the formula of the hydrated salt?
CuSO4 . 5H2O
I am trying to electroplate Iron with silver using a silver salt. What should my cathode and anode be?
Cathode - Iron
Anode - Silver
Draw the reaction pathway diagram of the formation of ammonia. Include the label of ΔH with an arrow.
Exothermic so reactants are higher than products on y axis, Ea must be shown and ΔH line is between products and reactants (pointing downwards)
1 min
Is there a reaction when bromine water is added to aqueous potassium iodide?
If no, why not?
If yes, what colour change would you see?
Yes
Colourless to Yellow/brown
Explain the differences.
Diamond - cannot conduct electricity - no free electrons
Diamond - stronger - all 4 carbons bonded, no layers
Graphite - layers can slide over each other - has layers weakly bonded together (only 3 bonds per carbon)
3 mins
25cm3 of 0.15mol/dm3 barium hydroxide was required to neutralise 12.80cm3 of nitric acid. What is the concentration of nitric acid in g/dm3?
Equation:
Ba(OH)2 (aq) + 2HNO3 (aq) --> Ba(NO3)2 (aq) + 2H2O (l)
Mols of Ba(OH)2 = 0.15 x 0.025 = 0.00375 mols
Mols of HNO3 = 0.00375 x 2 = 0.0075
Concentration of HNO3 = 0.0075/0.0128 = 0.59mols/dm3
Concentration of HNO3 = 0.59 x 63 = 37.17g/dm3
What is formed at the anode of aqueous concentrated sodium chloride? Write out the ionic half-equation for this reaction.
2Cl- + 2e- -> Cl2
3 mins
Iron reacts with copper(II) sulfate to form iron(II) sulfate and copper.
Write out:
- The net ionic equation incl state symbols
- The half ionic equations (both) incl state symbols
- Identify the reducing agent.
Fe0 (s) + Cu2+ (aq) --> Fe2+(aq) + Cu0(s)
Fe0 --> Fe2+ + 2e-
Cu2+ + 2e- --> Cu0
Fe0 is the reducing agent as it gets oxidised (loses electrons)
1 min
How can you make lead sulfate?
Include all the chemicals you would use and write out the ionic equation for this incl state symbols.
any 2 soluble salts
Pb2+ (aq) + SO42- (aq) --> PbSO4 (s)
AgI
Ionic bonds - lattice structure. High electrostatic attraction.
2 mins
9.2g of sodium reacted with 8.0g of sulfur to produce sodium sulfide.
2Na + S --> Na2S
Which reactant is the limiting reactant? Explain.
Mols Na = 9.2/23 = 0.4
Mols of S = 8.0/32 = 0.25
Na is the limiting reactant.
This is because to react with all of 0.25mols of S, we require 0.25x2 = 0.5mols of Na but we only have 0.4mols
What is formed at the anode of aqueous concentration sulfuric acid? Write out the ionic half-equation.
Oxygen gas
4OH- --> 2H2O + O2 + 4e-
2 mins
2 drops of potassium manganate are added to a well of potassium iodide.
What is the colour change seen?
Write out the half- ionic equation for iodine incl state symbols.
Identify whether potassium iodide is an oxidising agent or a reducing agent.
Colourless to brown.
2I- (aq) --> I2 (aq) + 2e-
KI is a reducing agent as it gets oxidised (I- loses electrons)
4 mins
A chemist is trying to find the concentration of a solution of calcium hydroxide.
The chemist has a 0.1M of dilute hydrochloric acid.
The chemist finds that they need to use 0.02 dm3 of hydrochloric acid (in burette) to neutralise 0.025cm3 of calcium hydroxide (in conical flask). The chemist used thymolphthalein indicator for this.
What is the concentration of calcium hydroxide in mol/dm3?
What was the colour change seen?
Hint: You will need a balanced chemical formula to figure this out.
Colour change: Blue to colourless
Concentration:
Ca(OH)2 + 2HCl --> CaCl2 + 2H2O
Mol of HCl: 0.02 x 0.1 = 0.002
Mol of Ca(OH)2 = 0.002/2 = 0.001
Concentration of Ca(OH)2 = 0.001/0.025 = 0.04 mol/dm3