Search found 795 matches

by ChenBeier
Sat Jul 24, 2021 2:50 am
Forum: Chemistry forum
Topic: Electron-transfer reaction
Replies: 1
Views: 30

Re: Electron-transfer reaction

The basic is the law of faraday

m = I * t * c
c = electrochemical equivalent =M/ (z *F)

m= mass, I = current, t= time, M = molar mass, z = amount of transferred electrons, F = Faraday constant 96485 As,
by ChenBeier
Thu Jul 15, 2021 12:27 am
Forum: Chemistry forum
Topic: Buffer
Replies: 1
Views: 100

Re: Carbonate and bicarbonate

Nothing happen.

pH = pKs - log((cHCO3-)/(cCO3 2-))
by ChenBeier
Mon Jul 05, 2021 10:58 am
Forum: Chemistry forum
Topic: Computing mass of CaF₂
Replies: 3
Views: 144

Re: Computing mass of CaF₂

I think the amount is driven from the limiting agent. Ca 2+ is limited ion. Everything what is above the soloubilty will precipitate. Its about 2.38 g.
by ChenBeier
Mon Jul 05, 2021 5:40 am
Forum: Chemistry forum
Topic: Computing mass of CaF₂
Replies: 3
Views: 144

Re: Computing mass of CaF2

Check what is limiting agent.
by ChenBeier
Thu Jul 01, 2021 12:43 am
Forum: Chemistry forum
Topic: Thermochemistry questions(1)
Replies: 5
Views: 214

Re: Thermochemistry questions(1)

The absorbtion of 823,7 kJ/ mol for water is correct. But how you get the other values. What is the 7nitial temperature of iron?
by ChenBeier
Wed Jun 30, 2021 5:44 am
Forum: Chemistry forum
Topic: Thermochemistry question part (2)
Replies: 3
Views: 144

Re: Thermochemistry question part (2)

Who said that. In first it was told your result is wrong. So take the equation half, the Addition of educt is one enthalpy value. The product also have value, what has subtracted vom educt value, it gives negative value. The cobaltoxide reaction. First CoO is formed with negativ value, from there Co...
by ChenBeier
Wed Jun 30, 2021 3:11 am
Forum: Chemistry forum
Topic: Balance chemical equation
Replies: 1
Views: 153

Re: Balance chemical equation

Sounds ok
by ChenBeier
Wed Jun 30, 2021 3:05 am
Forum: Chemistry forum
Topic: Thermochemistry question part (2)
Replies: 3
Views: 144

Re: Thermochemistry question part (2)

The first one is -59.65 kJ/ mol educt- product.

The second one 3*(-120,6 kJ/mol) + (-632,4 kJ/mol) = -994,2 kJ/ mol
by ChenBeier
Tue Jun 29, 2021 10:44 pm
Forum: Chemistry forum
Topic: Thermochemistry questions(1)
Replies: 5
Views: 214

Re: Thermochemistry questions(1)

It is not asked. You can calculate the heat what was absorbed by the water.
But you could calculate the Initial temperature of iron.
by ChenBeier
Tue Jun 29, 2021 10:39 pm
Forum: Chemistry forum
Topic: Thermochemistry question
Replies: 3
Views: 130

Re: Thermochemistry question

You changed the question after I answered. The answer refered to the first 2 questions. I meant 1 and to 2 are correct.

Then only 3a is correct

And 4 b
by ChenBeier
Tue Jun 29, 2021 10:02 pm
Forum: Chemistry forum
Topic: Thermochemistry question
Replies: 3
Views: 130

Re: Thermochemistry question

Both are correct.
by ChenBeier
Mon Jun 28, 2021 2:03 pm
Forum: Chemistry forum
Topic: Unit Conversion mol/kg to mmol/g
Replies: 11
Views: 331

Re: Unit Conversion mol/kg to mmol/g

If CO2 will dissolved in NaOH solution, then it will be converted to sodiumcarbonate.
There is no free carbondioxide left.
1,3 m NaOH has specific gravity of 1,05 g/ml
With this number you could calculate further but its hypothetic.
by ChenBeier
Mon Jun 28, 2021 1:32 pm
Forum: Chemistry forum
Topic: Unit Conversion mol/kg to mmol/g
Replies: 11
Views: 331

Re: Unit Conversion mol/kg to mmol/g

What is the question with it.
by ChenBeier
Fri Jun 25, 2021 11:55 pm
Forum: Chemistry forum
Topic: Unit Conversion mol/kg to mmol/g
Replies: 11
Views: 331

Re: Unit Conversion mol/kg to mmol/g

You need the specific gravity of the solution not from CO2. As already mentioned you can say 1 kg ~1 L but this is inaccurate.
by ChenBeier
Fri Jun 25, 2021 12:36 pm
Forum: Chemistry forum
Topic: Unit Conversion mol/kg to mmol/g
Replies: 11
Views: 331

Re: Unit Conversion mol/kg to mmol/g

44.01 Apples or what. Need correct unit. Then can use m = n* M
For converting L to g need specific gravity.