Practical investigations
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Activation energy: what answer did you get?
Every year a lot of people investigate the reaction of magnesium with acid. What is the activation energy for this reaction?
Here is a typical question coming in to this site:
I have carried out an experiment between magnesium and hydrochloric acid, in order to find out the activation energy of the reaction.I have used 1M HCl. I have now calculated the activation energy but I don't know if you could give me an indication of what I should be getting?
Our reaction:
In response we have been asking you to tell us your results. Please report your results here by clicking on 'react' below. Please remember to state:
- the metal (it is not always magnesium)
- the acid
- your value for the activation energy including the units.
Now that we have had a lot of results reported (see below) you can use them in your evaluation. Pick out the values for the acid and metal you are interested in. Note the range of values and the mean value. See where your result lies in relation to the mean and range. Comment on the degree of measurement uncertainty suggested by all the results reported here.
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Reactions
N.A
0.02g (2cm) Mg reacting with
0.1M Ethanoic acid 20.50kjmol-1
1.2M Ethanoic acid= 25.33
1.4M Ethanoi acid = 27.02
1.6M Ethanoic acid = 29.33KJmol-1
30 April 2008
na
0.02g of Mg reacting with Ethanoic acid of diff conc
0.1M = 20.50
1.2M = 25.33
1.4M = 27.02
1.6M = 29.33KJmol-1
30 April 2008
Erica
2M hydrochloric acid with magnesium (1 1/2 inches of magnesium ribbon) gave a result of 45000 J/mol-1/K-1
27 April 2008
Kevin123
I used a large excess of HBr hydrobromic acid with magnesium:
4 litres 2M HBr with 10cm3 mg gave Ea of 3.24kJmol-1
also for Boric acid same quantities gave Ea of 14.3kJmol-1
23 April 2008
Gareth Buckley
HCL(1M)+ Magnesium - +20.5 KJmol-1
H2SO4(1M)+ Magnesium - +15.5 KJmol-1
16 April 2008
Aysha
These are dodgy but 2M HCl (in excess) reacting with 0.04g of Mg ribbon gave an activation energy of +7.39 KJ mol-1.
2M H2SO4 (in excess) with 0.04g of Mg ribbon was +10.84 KJ mol-1. Worst coursework i've ever done in my life.
13 April 2008
Marcus
HCl (1 mol l-1, not that it matters xD) with 0.05g of Mg => 25.1 kJ mol-1
CH3COOH (also 1M) with 0.05g of Mg => 34.7 kJ mol-1
02 April 2008
Shensisque
All reactions are with 10cm^3 2M acid and 0.048g Mg Magnesium ribbon.
2M HCl Hydrochloric acid pH -0.69 -> 7.62 kJ/mol
2M HNO3 Nitric acid pH -0.65 -> 8.53 kJ/mol
2M CH3COOH Ethanoic acid pH 5.15 -> 28.4 kJ/mol
From considering possible errors in my experiment, I can guess that the actual values should be higher than this, particularly for the stronger acids.
24 March 2008
gary
o.15g mg, 8.2 dm3 of 1M HCL: EA of 13.85KJmol-1
18 March 2008
Emily
0.5M HCL + 0.2g Mg ribbon EA = + 21.3 kJ mol-1
0.5M ethanoic + 0.2g Mg ribbon EA = + 46.8 kJ mol-1
12 March 2008
Ryan
1M ACID + MAGNESIUM
Nitric - 20.76 kJ mol-1
Trichloroethanoic - 33.24 kJ mol-1
Chloroethanoic - 49.86 kJ mol-1
Ethanoic - 81.25 kJ mol-1
02 March 2008
aimé
4.0M HCl reacting with 0.5g Zn powder
EA = +20.15 or +21.40 depending on accuracy of best-fit line
27 February 2008
aimé
2.0M HCl reacting with 2cm Mg ribbon (approx. 0.3g)
EA = +20.78 or +21.34 depending on accuracy of best-fit line
25 February 2008
Lindsey
HCl + Mg gave me an EA of +33.24
21 February 2008
sid werth
25cm3 of 1M HCL reacting with 2cm of mg (0.02802g) Activation energy = +17.26kjmol
20 February 2008
J.K
(1) 1M of Hcl + Mg ribbon(0.3gappx) EA= +18.2
(2 1M of CH3CH2CO2H + Mg ribbon (0.3g appx) EA= +43.5
06 January 2008
s.Y
0.1g Mg + 1M HCL = 26.59KJ mol
0.1g MG + 1M CH3COOH = 46.17 KJ mol
03 January 2008
George.K
0.06g Mg + 10cm3 H2SO4 0.25M: Ea= +12.0 Kjmol-1
0.06g Mg + 10cm3 HCL 0.5M: Ea= +14.2kjmol-1
21 December 2007
sj
Magnesium and hydrochloric acid: 11.5 Kj
Magnesium and sulphuric acid: 6.6 Kj
04 December 2007
jmmL
3cm Mg, 1M HCl, Ea = 29.7 kJ/mol, HCl is 2nd-order
18 November 2007
Lj
Mg + HCl = MgCl + H2
Ea = +32.3KJ/mol
I repeated with 2M, 1.8M, 1.6M, 1.4M, 1.2M, 1M and 0.8M as Ea will remain constant
17 November 2007
James Finch
1M Hydrochloric acid with 0.1g Magnesium - Ea = +18.6 KJ mol
1M sulphuric acid with 0.1g Magnesium - Ea = +12.6 KJ mol
1M phosphoric acid with 0.1g Magnesium - Ea = +3.7 KJ mol
12 November 2007
Jeremiah Cheung
2cm Mg Ribbon + 1M HCl gave me Ea of +24.2kJmol-1.
12 November 2007
Ed Jones
1M Ethanoic acid with 0.1g magnesium gave me Ea of +46.90 kJmol-1
1M Hydrochloric acid with 0.1g magnesium gave me Ea of +26.13 kJmol-1
11 November 2007
josh
4cm og Mg ribbon and 1M HCl gave an activation energy of 32.2 kJ/mol
11 November 2007
Fran
1M ehtanoic acid + 0.266g Mg gave 53.2
01 November 2007
FamLuuuuuu
0.1g of Mg with 1m HCL,EA = 14 and 0.1g with 1m H2SO4,EA = 15
28 October 2007
leah
10 cm of 0.75M HCl with 0.09g Mg
Ea= 16 kJmol-1
27 October 2007
Stephen Webb
1M HCL + 0.02g Mg gave +42.1 KJ/mol
2M CH3cooh + 0.02g Mg gave +47.3 KJ/mol
15 October 2007
Jimmy Tao
Mg + HCl ribbon Ea = 14.1 kJ/mol and powder Ea = 13.8 kJ/mol; not significantly different.
08 October 2007
Paul
15cm3 of 0.5 HCl + 1g of Mg. EA = 18 kJ mol-1
10 May 2007
zigg
2M HCl and 2cm Mg strip = +1.99 Kj mol
2M CH3COOH and 2cm Mg strip = +12.7Kj mol
08 May 2007
Ian Cleghorn
7.5 cm3 of 0.5M Ethanoic Acid + 6g (10x for excess) Mg
EA = +31kJ mol-1
07 May 2007
Amy
1M HCl and 5cm Mg had Ea of 13kj/mol
1M Ethanoic acid and 5cm Mg had Ea of 28kj/mol
26 April 2007
BMJ
2M Hydrochloric Acid + 5cm Mg; EA = 5.18 KJ/mol
1M Ethanoic Acid + 5cm Mg; EA = 48.5 KJ/mol
25 April 2007
E.J Igbinovia
2M HCl and 4cm piece of Mg ribbon
Average Activation energy is +24KJ mol-1
1M H2SO4 and 0.100g mass of Mg ribbon
average activation energy is +15KJ mol-1
25 April 2007
Esy
Activation Energies;
1M Hydrochloric Acid - 26.18 KJ/mol
1M Ethanoic Acid - 33.78 KJ/mol
14 April 2007
Eug SIS 07
0.5M - HCl and H2SO4 - Mg 0.02g (approx. 1cm)
Ea of HCL: 33 kJ/mol
Ea of H2SO4: 17 kJ/mol
22 March 2007
gelesa
1M hydrochloric acid and 0.05g of magnesium - activation energy is 6.31kJ per mole. 1M sulphuric acid and 0.05g of magnesium - activation energy is 5.61 kJ per mole.
18 March 2007
Juliette
Values for activation energies:
0.5M HCl and Mg = 19.7 kJ/mol
0.5M H2SO4 and Mg = 9.8 kJ/mol
15 March 2007
Sam
50 ml HCl and 3cm of magnesium gave 10kj/ mol
and same with ethanoic acid gave 39 kj/ mol, which seems ok, on the lower end!
09 March 2007
Anupama
1M hydrochloric acid and 0.05g of magnesium - activation energy is 6.32kJ per mole.
1M sulphuric acid and 0.05g of magnesium - activation energy is 5.61 kJ per mole
04 March 2007
Amy
5cm strip of magnesium (0.06g) reacted with 2.0M hydrochloric acid Ea of 21.9kJmol-1 and
with 2.0M ethanoic acid Ea of 46.5kJmol-1
01 March 2007
Emma
2cm strip of Magnesium with 300 ml of 0.5M hydrochloric acid
with stirring: +31.2 kJ/mol
without stirring: +33.5 kJ/mol
27 February 2007
Will
Sodium thiosuphate and hydrocholric acid. Ea =69.6 kJmol
08 February 2007
Aimee
0.5M HCL with Mg ribbon.
Activation energy: 24.942 KJ per mole
21 December 2006
MightyBen
Activation energies:
0.5g magnesium, 150ml hydrochloric: 68.3 kJ/mol
0.5g magnesium, 150ml sulphuric: 25.4 kJ/mol
0.5g magnesium, 150ml ethanoic: 69.8 kJ/mol
0.5g magnesium, 150ml nitric: 93.2 kJ/mol
20 December 2006
TG
0.06g of Mg ribbon reacted with 5ml of 1M phosphoric acid results in a activation energy of 18.2 KJ mol.
0.06g of Mg ribbon reacted with 5ml of 1M hydrochloric acid results in a activation energy of 49.9 KJ mol.
note that these results had a substantial margin of error.
16 December 2006
Fraeya
0.5g Mg with HCl= + 11.5 kJmol-1
0.5g Mg with H2SO4= + 20.4 kJmol-1
07 December 2006
Joe
3M HCL and 0.064g Mg = +4.89 kJ/mol
3M sulphuric and 0.064g Mg = +9.82 kJ/mol
(Now ive got to explain why that happened!!)
19 November 2006
Sir Egbert
50ml 1.0M Hcl with 0.038g Mg
33.1kj/mol
19 November 2006
Naddia Abid
30 ml of 0.5M HCl when reacted with 0.015g of Mg gives the activation energy of 33 kJ per mole
16 November 2006
Rachel
2M HCL + 0.03g Mg
Activation Energy = 41.6 kJ/mol
15 November 2006
Rachel
0.05g Mg(s) with 40ml 1M HCl(aq)
EA= + 26.21 kJ/mol
05 November 2006
Attiya Ahmed
20 ml of 0.5M HCl with 0.024 g Mg has activation energy 49 kJ/mol
27 October 2006
debbie
Mg + HCL
Ea = 15.109 KJ mol-1
Mg + H2SO4
Ea = 29.679 KJ mol-1
17 October 2006
Omar EL-Said
Ea
Mg (0.08g) and HCl (2M, 10cm3) = 4.8 kJ per mole
Mg(0.08g) and ethanoic acid (2M, 10cm3) = 58.5 kJ per mole
20 August 2006
Aisai
Magnesium metal and hydrochloric acid
Activation energy = 9.2 kJ/mol
11 May 2006
mikey
I used 1M HCl, and my value for the activation energy was 23.3 kJ/mol.
I also got second order with respect to [HCl].
02 May 2006
zack
I carried out an experiment to find the activation energy for 0.1M sodium thiosulphate, and 0.05M HCl, I achieved an Ea = 18 kJ/mol
01 May 2006
Adrian V
I got Ea = + 88.1 kJ/mol at 25 oC
HCl 0.1737 M, 10 cm Mg strip
06 April 2006
Tris
1M HCl with 0.003 g Mg
Ea = 52 kJ/mol
31 March 2006
Nathaniel
2M sulphuric acid with 0.1 g of Mg
Ea = 12.2 kJ/mol
2M HCl with 0.1 g of Mg, I got Ea = 15 kJ/mol
4M ethanoic acid with 0.1 g of Mg, Ea = 26.9 kJ/mol
19 March 2006
Dante
HCl - 1M - With agitation 0.039 g Mg
Ea = 30.8 kJ/mol
HCl - 1M - No agitation 0.039 g Mg
Ea = 27.2 kJ/mol
(Funny result huh? I think its due to the massive endothermic reaction happening right next to the magnesium causing a greater local temperature and therefore a greater rate of reaction!)
18 March 2006
Dominic
20 ml of 0.2M HCl with excess Magnesium
Ea = 23.86 kJ/mol
07 March 2006
Anne
0.25M HCl (20 cm3) with excess Mg
Ea = +24.93 kJ/mol
07 March 2006
Tom
Results: 30 ml 0.6 M HCl with Mg:
Ea = + 21.3 kJ/mol
05 March 2006
Risa
For 50 ml 0.7M hydrochloric acid + 3 cm Mg ribbon:
Activation energy = +27.7 kJ/mol
For 50 ml 0.4M sulphuric acid + 3 cm Mg ribbon:
Activation energy = +29.4 kJ/mol
05 March 2006
AJ
1M HCl (20 cm3) with 0.02 g Mg :
Ea = 28.15 kJ/mol
05 March 2006
Phil
Results:
40 ml 1.0 M HCl with Mg:
Ea = + 16.6 kJ/mol
27 February 2006
Sonia
I varied the metal:
20 cm3 HCl 1M
Mg: Ea = 9.4 kJ/mol
Zn: Ea = 13.3 kJ/mol
21 February 2006
pooja
My results:
Ea of HCl is 31 kJ/mol
Ea of H2SO4 is 15 kJ/mol
20 February 2006
Sally
1M HCl 0.02 g Mg
Ea = 45 kJ/mol
20 February 2006
Morzeena
Mg with HCl (1.5 M)
Ea = + 16.7 kJ/mol
20 February 2006
Damien
2M H2SO4 + Mg
Ea = + 12.2 kJ/mol
20 February 2006
Hurst
4 cm3 of 1 M HCl with 0.5 g of magnesium (excess)
Ea = 18.89 kJ/mol
4 cm3 of 1 M H2SO4 with 0.5 g of magnesium (excess)
Ea = 24.93 kJ/mol
19 February 2006
Em
2M HCl + Mg (0.03 g)
Ea = + 12.7 kJ/mol
2M ethanoic acid + Mg (0.03g)
Ea = + 43.9 kJ/mol
19 February 2006
Izzy
HCl 10 cm3 0.8 M with 0.05 g Mg
Activation energy = +16.8 kJ mol-1
18 February 2006
Beccy
Mg with HCl (0.5M)
Ea = 12.2 kJ/mol
Mg with CH3COOH (0.5M)
Ea = 17.7 kJ/mol
18 February 2006
wardy
1 mol/litre HCl
1 cm Mg ribbon
Activation energy=16.6 kJ/mol
17 February 2006
abi
1M HCl
0.055 g (4 cm) Mg
Ea = 11.4 JkJ/mol
16 February 2006
Poppy
Mg + 2HCl -> MgCl2 + H2
I found the activation energy for this reaction to be 16.12 kJ/mol
15 February 2006
Jenni McCann
Magnesium
Hydrochloric Acid
Activation energy 26.8 kJ/mol
14 February 2006
Lauren
Using 1M acid and 0.03 g of Mg
14.32 kJ/mol for hydrochloric acid
11.95 kJ/mol for sulphuric acid
12 February 2006
Francois Bertrand
Mg 0.1 g and HCl 2M
Activation energy = 3.57 kJ/mol
24 January 2006
Niro
I used 2M HCl and 0.2 g Mg
Ea = 3.1 kJ/mol
for 2M HCl and 0.2 g zinc, Ea = 8.1 kJ/mol
30 December 2005
Lloydy B
I used 2M ethanoic and got 46300 J/mol with 0.03 g of Mg.
With 2M hydrochloric I got 14000 J/mol, which seems a bit low.
08 December 2005
Meera
For 0.5M of HCl and 0.06 g (4cm) Mg, the activation energy = +38.77 kJ/mol
08 December 2005
Nellie Premchand
0.1M HCl with 5 cm Mg ribbon
My value for activation energy = +19.23 kJ/mol
04 December 2005
Abi
1M HCl + Mg
Eactivation = + 18.7 kJ/mol
25 November 2005
Laura-Jay
1M hydrochloric acid with 0.02 g magnesium
activation energy = 18.7 kJ/mol
1M ethanoic acid with 0.02 g magnesium
activation energy = 36.6 kJ/mol
14 November 2005
Vidya
Using 10 cm3 of 1M HCl with about 0.15 g Mg, I got an Ea of 26 kJ/mol.
Using 10 cm3 of 1M ethanoic, with about 0.15 g Mg, i got an Ea of 19 kJ/mol.
14 November 2005
Ruth
HCl + Mg: Ea = +12.08 kJ/mol
H2SO4 + Mg: Ea = +12.80 kJ/mol
13 November 2005
Miraj
1M HCl and 0.1g Mg
Activation Energy = 11.7 KJ/mol
31 October 2005
Jamie
0.015 moles Zn powder with excess HCl (0.02 moles)
Ea (uncatalysed) = + 51.11 kJ mol-1
Ea (catalysed with 9.09 x 10-3 mol Cu2+) = + 18.38 kJ mol-1
22 October 2005
julie
Magnesium and hydrochloric acid
Activation energy = +34 kJ/mol
13 October 2005
TeXMeX
For reaction at different temperatures (25, 30, 35, 40 degrees Celcius)
1 M HCl 1 cm Mg strip (width 3 mm) exposed on only 1 side
Activation Energy = + 32.7 kJ/mol
17 September 2005
Katharine
I used 0.5M HCl and 0.19 c of Mg and got an Activation Energy of 25.9 kJ/mol.
I compared this with a reaction of 1.0M HCl and 0.26 g of Zinc which had an Activation energy of 5.5 kJ/mol.
15 May 2005
rosie
Values for activation energies:
1M HCl and Mg = 23.4 kJ/mol
1M H2SO4 and Mg = 10.2 kJ/mol
08 May 2005
Firas AlJayoosi
Mg(s) + HCl(aq)
Recalculated activation energy = +13.5 kJ/mol
19 April 2005
Pewter Moon
Zinc + hydrochloric acid
Activation energy = 61.3 kJ/mol
Zinc + sulphuric acid
Activation energy = 22.6 kJ/mol
Magnesium + hydrochloric acid
Activation energy = 34.3 kJ/mol
Magnesium + sulphuric acid
Activation energy = 19.1 kJ/mol
11 April 2005
laura
(1M) HCL and 2 cm Mg (approx 0.04 g)
Activation energy = 24.6 kJ/mol
31 March 2005
Ross
0.5M Hydrochloric with Mg
Activation energy = +32 kJ/mol
0.5M Ethanoic with Mg
Activation energy = +17 kJ/mol
I also predicted that HCl would have the lower activation energy, and now im very stuck with explaining why it didnt!
26 March 2005
Mr Pecano
Magnesium with sulphuric acid. Activation energy = 32.107 kJ/mol.
13 March 2005
Tim Coveney
For magnesium and 1M acid,
I got an activationn energy of 14.96 kJ/mol
06 March 2005
Paul
About 7 kJ/mol for 1 mol dm-3 HCl and about 35 kJ/mol with 1 mol dm-3 ethanoic acid.
06 March 2005
Jess
1M HCl(excess) + Mg
Activation energy = 13.7 kJ/mol
1M H2SO4 (excess) + Mg
Activation energy = 11.0 kJ/mol
1M H3PO4 (excess) + Mg
Activation energy = 9.3 kJ/mol
02 March 2005
katie
Magnesium with 0.5M HCl
Activation energy = 28.6 kJ/mol
24 February 2005
Firas Al-Jayoosi
Mg and HCl acid
8.31 KJ/mol - value for the activation energy
23 February 2005
Jamie G
0.5M HCl/Ethanoic with Mg
Activation energy for HCl: + 25.5 kJ/mol
Activation energy for ethanoic acid: + 33.4 kJ/mol
22 February 2005
Laura
(0.5M) HCl + (0.048 g) Mg
Activation energy = - 29.3 kJ/mol
21 February 2005
Naomi
Activation energy for magnesium with -
21 February 2005
Jack W
I got +22.7 KJ/mol for the reaction of Magnesium and Hydrochloric acid which seems right and +9.36 KJ/mol for the reaction of Magnesium and Sulphuric acid which seems less right.
20 February 2005
Louise
My value for HCl reacting with magnesium is +22.4 kJ/mol. My value for ethanoic acid with magnesium is +19.8 kJ/mol. I would have expected the stronger acid to have the lower activation energy.
12 February 2005
Gavin
When reacting 3M HCl with 2 cm of magnesium ribbon, the activation energy I got was about 14 kJ /mol.
14 December 2004
Alice
With magnesium in my investigation I got 25 kJ/mol for the activation energy with HCl and 19.3 kJ/mol with ethanoic acid.
05 December 2004
Jo
Magnesium with HCl: I got 24.5 kJ/mol
05 December 2004
Helen
For 2 molar hydrochloric acid I got an activation energy of 25.2 kJ mol-1 and for 2 molar ethanoic acid I got an activation energy of 32.3 kJ mol-1. This was with magnsium ribbon.
05 December 2004
lucy
For magnesium reacting with hydrochloric acid I found the activation energy to be 24 kJ/mol.
28 November 2004
alice
I investigated the activation energies of ethanoic, sulphuric and hydrochloric acid. I used 0.25M sulphuric, 0.5M of hydrochloric and ethanoic. I used 20cm3 of all acids and I used an excess of 0.5 g of magnesium and got these results:
26 November 2004
Tom
0.5 mol HCl in excess and 0.06 g Mg ribbon. I calculated the activation energy to be 31.96 kJ mol-1.
17 November 2004
James Davies
1 cm of magnesium ribbon reacting with an excess of HCl, activation anergy calculated to be 24 kJ per mole.
12 November 2004
Caz
I’m doing coursework and have been investigating HCl with a) Mg and b) Zn, and finding the activation energies. From my results, I calculated Ea of Mg to be around +40 kJ/mol and Zn to be around +10 kJ/mol.
09 November 2004
Amanda
For 1M HCl I got 18.1 kJ/mol, and for 1M ethanoic I got 37.9 kJ/mol.
08 November 2004
James
With 1M HCl and 0.1 g Mg I got a value of 29.7 kJ mol-1 for the activation energy.
07 November 2004
Sophie
Activation energies. Magnesium ribbon:
28 October 2004
Lena
My results:
27 October 2004
Hala
My results:
23 April 2004
Pedge
I did zinc + sulphuric acid and I got the value to be 22.2 kJ/mol.
20 April 2004
heather
For 1 molar hydrochloric acid with 5 cm strip of magnesium, I got 17.3 KJ/mol. For 1 molar ethanoic acid with 5cm strip of magnesium, I got 47.0 KJ/mol
06 April 2004
Pete the Hacker
1M HCl, 6 cm of magnesium ribbon. Ea was + 14.83 kJ/mol.
18 March 2004
Lucia
For 1M HCl and 0.32 g Mg the activation energy was within the range of +10.2 kJ mol-1 to +24 kJ mol-1 and for 1M ethanoic acid with 0.32 g Mg it was +33.2 kJmol.
23 February 2004
Cathy
I got +27 kJ/mol with 1M HCl and 0.03 g of Mg
17 February 2004
James
I got 24.9kJ/mol for 0.5 M HCl with Mg
10 January 2004
Alex Gaastra
For the reaction of magnesium with three acids I got:
05 January 2004
Stephen Kyriacou
I found the activation energy of the HCl/magnesium reaction to between 27 and 32 kJ/mol
05 January 2004
Wally
My results were:
30.11kJ/Mol for HCl and Mg
and
40.24 kJ/Mol for CH3COOH and Mg.
19 December 2003
Richard
I got:
26 kJ/mol for Mg and HCl
20 kJ/mol for Mg and H2SO4
15 kJ/mol for Mg and H3PO4
02 December 2003
Peter Jack
For ethanoic acid and zinc I got 51.2 kJ mol-1 and for sulfuric acid and zinc I got 37 kJ mol-1. Did any one else do these experiments?
30 November 2003
cjblack
I got approx. 19 kJ/mol for HCl + Mg ribbon & 39.4 kJ/mol for CH3COOH, although my graphs are a bit dodgy...
23 November 2003
Jonathan Gilbert
All were with 0.5M acid and 0.1g Mg ribbon
18 October 2003
ruth
An average result would be useful. It would help too to have results for different acids such as phosphoric acid.
Note from the web editor: 'We can only publish the results that people submit to the site. No-one has sent in a result for phosphoric acid. As for average values, that is for you to work out if think it helpful and meaningful.
16 October 2003
Lucy Pittock
34.4 kJ mol-1 for 1M HCl and a 5 cm Mg ribbon.
08 October 2003
ABDI
I got +22.8 kJ mol-1 for Mg (0.1g) + HCl (2M).
26 September 2003
john m
I used 0.1 M of the following acids and reacted them with Mg Powder.
01 September 2003
Rob
I got 25.36 kJ mol-1 for HCl
for ethanoic acid I got 38.37 kJ mol-1.
06 April 2003
Amar
I got 2.8 kJ mol-1 for Mg + HCl
and 30 kJ mol-1 for Mg + Ethanoic acid
03 April 2003
Shanaz Hussain
I got 22.5 KJ mol-1 for sulphuric acid with magnesium ribbon.
10 March 2003
nicola
I got 24.8 KJ mol-1 using 1 M HCl at several different temperatures.
28 February 2003
Ahmed
I got 18.8 kJ mol-1 for HCL, did any one do Sulphuric acid, because I got a value of 20.3 kJ mol-1?
22 February 2003
Anna Roskilly
17.8 kJ mol-1 with 1M HCl
31 January 2003
James R
I used 0.35 M HCl and got +5.9 kJ mol-1, and 0.175 M H2SO4 and got +9.3 kJ mol-1 (both reacted with magnesium powder).
08 January 2003
Thomas Kohler
I got 24.6 kJ mol-1 for hydrochloric acid.
13 December 2002
Ophelia Woo
The activation energy value I got for HCl + Mg is +9.4 KJ/mol and for CH3COOH + Mg is +13.4 KJ/mol
10 December 2002
updated: 07 February 2006
