Practicals

Question 1

Describe the determination of the enthalpy change of neutralisation

Answer 1

Place a polystyrene cup in a 250 glass beaker
Measure 25cm HCL and put into cup
measure 25cm of NaOH
start timer and record initial temperature
record at 1,2,3 min and at 4 add naoh and stir then record at 5,6,7,8,9,10mins

Question 2

Describe the determination of enthalpy change of combustion

Answer 2

Measure 100cm of water into a beaker
weigh a burner with alcohols
heat the water in the beaker using the burner, take temp of water before stop when you’ve got a rise, take final temp of water and reweigh burner

Question 3

Describe determining Mr of Mg

Answer 3

measure 10.0cm of 1mol of H2SO4 to a conical flask
weigh 0.12-0.16 of Mg and record the measurement
remove the stopper add ribbon and replace stopper
collect gas and record the final volume of H
weigh evaporating basin and pour mgH2SO4, evaporate stop when crystals

Question 4

What were the results from Mr of Mg practical

Answer 4

Reduced voume due to Mg not fully reacting, increased volume due to H2O being displaced by air not H2

Question 5

Describe the determination of the formula of MgO

Answer 5

Measure mass of crucible and lid
Coil the mg ribbon and put in cruicubke and weigh again
Heat, when almost finished, placae lid on heat proog mat and heat for 5 mins tapping gently with tongs

Question 6

How do you make up a standard solution

Answer 6

Weigh out solid
Dissolve in water
Pour into conical flask and rinse beaker with water and include this in flask make up the make using distilled water

Question 7

Describe titrations

Answer 7

Fill burette with acid and record initial reading using a filter and rinse the burette through
remove the funnel and check theres no air bubbles
Transfer 25cm of standard solution and add drops of methyl orange
Titrate until it goes from yellow to orange whilst swirling the conical flask