other stoof

Question 1

expeiment to distinguish between electrolytes and non electro

Answer 1

1) when you place a conuductivity probe in an electrolyte, current flows through the circuit so you can measure its conductivity
2) when you place a conductivity probe in a non electrolyte, no current flows, so you’ll get a reading of zero conductivity

Question 2

using an electrolye cell to determine whether or not its an electrolyte

Answer 2

set up the cell, if it undergoes electrolysis then it is an electrolyte

Question 3

calorimetry- dissolving, displacment and neutalisation reaction

Answer 3

to measure the amount of energy transferred in these reactions just take the temp of the reagents (making sure theyre the same) mix them together and measure the temp of the solution at the end

Question 4

if you want to investigate the enthalpy change of dissolving, displacement or neutralisation

Answer 4

do this by mixing the reactamts in a polystyrene cup

the biggest problem with energy meauremenrs is the amount of energy lost to the surroundings, u can reduce this a bit by putting the polystyrene cup into a beaker full of cotton wool to give more insulation and putting a lid on the cup to reduce energy lost by evaportation

Question 5

molten cyrolite

Answer 5

Al203 has a very high melting point of over 2000 degrees c so melting it would be very expensive

instead the aluminium oxide is dissolved in molten cryolite (a less common ore of aluminum)

this brings the temp down to about 900 which makes it much cheaper and easier

the electrodes are made of graphite, a good conductor of electricity

Question 6

how are sulfur dioxide and nitrogen oxide formed

Answer 6

• released when fossil fuels are burnt
• the sulphur dioxide comes from sulfur impurities in fossil fuels
• the nitrogen oxides are created when the temp is high enough for the nitrogen and oxygen in the air to react, this often occurs in car engines