Search found 31 matches

by Neon
Mon Jun 12, 2023 12:00 am
Forum: Chemistry forum
Topic: Activity coefficient
Replies: 2
Views: 2047

Activity coefficient

Hello, I would like to know if I also have to square the activity coefficient in addition to the equilibrium constant of silver, if I want to express the solubility or solubility product Ag2SO4 . K sp = γ(Ag+)square *[Ag+]square *γ(SO42')*[SO42-] or K sp = γ(Ag+)*[Ag+]square *γ(SO42')*[SO42-] Thanks...
by Neon
Mon May 08, 2023 5:24 am
Forum: Chemistry forum
Topic: Solubility
Replies: 3
Views: 2225

Re: Solubility

I'm sorry, but I don't quite understand what you're trying to say. Could you please write a concrete numerical result?
by Neon
Mon May 08, 2023 2:26 am
Forum: Chemistry forum
Topic: Solubility
Replies: 3
Views: 2225

Solubility

Please help me with this task: The solubility product of As2S3 is 4.0.10−29 (T = 25 °C). a) Calculate the number of S{2-} ions in 70.0 L of saturated As2S3 solution at 25 °C. b) In 70.0 L of Na2S solution of unknown concentration, a maximum of 0.545 mg of As2S3 can be dissolved at 25 °C. Calculate t...
by Neon
Sat May 06, 2023 6:59 am
Forum: Chemistry forum
Topic: Titration
Replies: 3
Views: 2148

Titration

Please help me with the following task: 20.0 mL of acetic acid solution is titrated with 0.0510 M sodium hydroxide solution. a) Calculate the concentration of acetic acid if the pH at the equivalence point is 8.51! Assume additivity volume. Ka(CH3COOH) = 1.75·10-5 b) Calculate the volume of NaOH add...
by Neon
Tue Mar 14, 2023 8:34 am
Forum: Chemistry forum
Topic: Solubility of crystal hydrates
Replies: 4
Views: 3402

Solubility of crystal hydrates

Please answer my query concerning the solubility of crystal hydrates: Add 80.0 mL of a 15.0% CuSO4 solution with a density of 1.137 g/mL (T = 20 °C) to 30.0 g of solid CuSO4*5H2O and mix thoroughly. CuSO4 solubility (T = 20 C) = 20.8 g / 100 g water a.) Determine how many grams of CuSO4*5H2O remain ...
by Neon
Thu Dec 08, 2022 1:35 pm
Forum: Chemistry forum
Topic: Questions from general chemistry - mixing of solutions and balancing of equations of redox reactions
Replies: 3
Views: 3149

Re: Questions from general chemistry - mixing of solutions and balancing of equations of redox reactions

I appreciate your work, but I'm afraid I don't entirely comprehend how you arrived at the conclusion. What is the origin of the numerals 10,4 and 12? I'm also curious in the redox process and how it would balance, say, if it had hypothetical significance. In the book where the reaction was written, ...
by Neon
Thu Dec 08, 2022 7:23 am
Forum: Chemistry forum
Topic: Questions from general chemistry - mixing of solutions and balancing of equations of redox reactions
Replies: 3
Views: 3149

Questions from general chemistry - mixing of solutions and balancing of equations of redox reactions

Hello, I have two questions: 1. We want to prepare a 20.0% KOH solution. We have at our disposal a 9.96% KOH solution with a density of 1.090 g mL–1 (T = 20 °C) and a 32.0% KOH solution with a density of 1.310 g mL–1(T = 20 °C). a.) Calculate in what volume ratio we must mix the 9.96% and 32.0% solu...
by Neon
Sun May 08, 2022 7:11 am
Forum: Chemistry forum
Topic: Electrolysis
Replies: 5
Views: 13305

Re: Electrolysis

Even I calculated it, the result is the same as yours. This is an example from a chemical competition, and the official answer is 14 A. But now I'm not sure what to do, so I turned to this forum for help. So you don't believe it's possible to achieve 14 amperes in any case?
by Neon
Sat May 07, 2022 11:36 pm
Forum: Chemistry forum
Topic: Electrolysis
Replies: 5
Views: 13305

Re: Electrolysis

Thanks, but the problem is that the solutions say the answer is 14 A. Is that possible?
by Neon
Fri May 06, 2022 5:52 am
Forum: Chemistry forum
Topic: Electrolysis
Replies: 5
Views: 13305

Electrolysis

31 g of pure K3PO4 are dissolved in 250 g of distilled water at a density of 1 g / mL. The resulting solution is then electrolyzed for 14 hours under constant electric current. After electrolysis, the mass fraction of salt in the solution increases by 3.4%, and the mass and appearance of the electro...
by Neon
Tue Jan 18, 2022 1:19 pm
Forum: Chemistry forum
Topic: A mixture of two ionic compounds
Replies: 1
Views: 1883

A mixture of two ionic compounds

Hello,

I would like to ask you a question about a mixture of two ionic compounds:

If we dissolve equal amounts of NaCl and KI in water and then evaporate the solvent, is it possible that I end up getting some NaI and KCl as well? Why yes or why not?


Thank you in advance!
by Neon
Wed Jan 12, 2022 9:25 am
Forum: Chemistry forum
Topic: Nernst equation
Replies: 1
Views: 1852

Nernst equation

Hello,

I would like to ask you a question about Nernst equation. So this is the correct notation of Nernst's equation if I want to calculate the pH measured with a pH meter?:
\( E= E0 + (2,3RT)/(nF) * pH \)
So does a pH meter use this equation to calculate pH?




Thank you in advance!
by Neon
Sat Jan 08, 2022 12:45 pm
Forum: Chemistry forum
Topic: Sample preparation for flame photometry
Replies: 0
Views: 29482

Sample preparation for flame photometry

Hello, I would like to ask you a question about preparing a sample for flame photometry: The calibration curve is in the range 0 - 20 mg Na{+} / L. The liquid sample contains only 0.55 mg Na{+} / L. How will you prepare the sample until the signal in the flame photometric analysis falls into the cen...
by Neon
Sun Dec 05, 2021 8:32 am
Forum: Chemistry forum
Topic: Titrations of the mixture of bases
Replies: 1
Views: 2017

Titrations of the mixture of bases

Hello,

I would like to ask you a question about titration:

To neutralize 1 gram of a sample containing KOH and Ba(OH)2 13.5 mL of hydrochloric acid at a concentration of 1 mol/L was used. What is the composition of the sample?


Thank you in advance!
by Neon
Fri Nov 19, 2021 9:46 am
Forum: Chemistry forum
Topic: Titration of mixture of strong and weak acid
Replies: 1
Views: 2046

Titration of mixture of strong and weak acid

Hello, I would like to ask you a question about titration of mixture of strong and weak acid: 50.0 ml of a solution containing HCl and a weak acid HX consume 48.7 ml of 0.115 M NaOH when titrated to phenolphthalein. Titrate the other 50 ml to methyl orange and consume 17.4 ml of base. What is the mo...