Calculations, Electrolysis Flashcards

1
Q

What is the Relative Formula Mass for MgCl2?

A

24 + (35.5 * 2) = 95

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What does it mean if a salt is Anhydrous?

A

Salt doesn’t contain any water of crystallisation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What does it mean if a salt is Hydrated?

A

A salt contains water of crystallisation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is Electrolysis?

A
  • Breaking down of a substance using electricity
  • Electric current passed through electrolyte causing it to decompose
  • Oxidation and reduction occur
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is Oxidation?

A

Loss of electrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is Reduction?

A

Gain of electrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are Ionic Half Equations?

A

Show how electrons are transferred during reactions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How do you Write Half Equations?

A
  • Put 1 thing as being oxidised/reduced on one side of arrow, the thing it gets oxidised it reduced to on the other
  • Balance up number of atoms
  • Add electrons (e^-) onto one side to balance up charge
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are Molten Ionic Compounds?

A
  • Electrolysed because ions move freely
  • Broken into their elements
  • E.g. molten lead bromide (PbBr2)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How do you sort up an Electrochemical Cell for an Aqueous solution?

A
  • Get 2 inert electrodes (graphite or platinum electrodes)
  • Clean surface of electrode using emery paper (or sandpaper)
  • Place electrodes into beaker filled with your electrolyte
  • Connect electrodes to power supply using wires and crocodile clips
  • Turn power supply on and a current will flow through cell
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is an Electrochemical Cell?

A
  • Circuit

* Made up of: anode, cathode, electrolyte, power source, wires that connect 2 electrodes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How can you reduce a Metal Oxide (copper II oxide) to find its Empirical Formula?

A
  • Place bung into test tube with hole at end, weigh using balance
  • Take bung out and put copper(II)oxide in middle of tube
  • Put bung in and weigh again
  • Use Bunsen burner to heat copper(II)oxide until changes colour from black to pink
  • Turn of heat and leave to cool
  • One cooled, weigh test tube with bung and contents
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How can you find the Empirical formula using Combustion?

A
  • Heat crucible to get it clean
  • Cool it then weigh it (initial)
  • Add magnesium ribbon,reweigh
  • Mass of magnesium is this reading minus initial reading
  • Heat crucible until magnesium turned white, lid on, leave small gap so oxygen can enter
  • Cool it then reweigh
  • Mass of magnesium oxide is this reading, minus initial reading
How well did you know this?
1
Not at all
2
3
4
5
Perfectly