Thursday, December 9, 2010

Reaction #5 - How to make carbonic acid

Carbonic acid is a weak acid, but if you want to make it, here's how:
Materials:
  • Vinegar / calcium chloride powder (vinegar - please follow normal steps and "A" steps, calcium chloride - please follow normal steps and "B" steps)
  • Sodium bicarbonate
  • Water
  • 25ml graduating cylinder
  • 1000ml (1 litre) beaker
  • Conical flask with hole at the side that connects to a glass pipette
  • Stopper
Step 1: Place the 25ml graduating cylinder into the 1000ml beaker.
Step 2: Pour the sodium bicarbonate into the conical flask.
Step 3: Pour water into the graduating cylinder.
Step 4: Put the glass pipette into the graduating cylinder.
Step 5A: Pour the vinegar (a bit will do) into the conical flask and stopper it off.
Step 5B: Add the calcium chloride into the conical flask and then add 10 ml of water (stopper it off immediately).
Step 6: Wait till no more gas bubbles come out of the pipette.
Step 7: Obtain the product (it's in the graduating cylinder)
Here're the chemical equations of this process:
For A:
Sodium bicarbonate + Vinegar (Acetic / ethanoic acid) Sodium acetate / ethanoate + Water + Carbon dioxide
NaHCO3 + CH3COOH CH3COONa + H2O + CO2
For B:
Sodium bicarbonate + Calcium chloride Sodium chloride + Calcium carbonate + Water + Carbon dioxide
2NaHCO3 + CaCl2 2NaCl + CaCO3 + H2O + CO2
(This actually goes in a multi-step process but I'm just simplifying it here.)
In both steps, the carbon dioxide dissolves into the water in the graduating cylinder to form carbonic acid:
Carbon dioxide + Water → Carbonic acid
CO2 + H2O H2CO3
Improvements: Add crushed ice and water to the beaker containing the graduating cylinder (increases yield because gases dissolve better in colder water).
 
Good luck! 加油!

Reaction by GITS

Tuesday, November 30, 2010

Reaction #4 - How to make copper(II) sulfate

Copper(II) sulfate, also known simply as copper sulfate (chemical formula: CuSO4), is the most commonly-used copper compound in laboratories. Due to the fact that it is commercially available (in fact, it is very widely available in many areas), it is not commonly prepared in laboratories.

That is why I am going to show you how to make copper sulfate here.

This is the more simple and straightforward way to make it:

Copper + Sulfuric acid → Copper sulfate + Sulfur dioxide + Water
Cu (s) + 2 H2SO4 (l) → CuSO4 (aq) + SO2 (g) + 2 H2O (l)

If you don't have sulfuric acid available, you can use this method, although you will need to pass an electric current through it with 2 electrodes made of copper to carry out electrolysis:

Cu (s) + MgSO4 (aq) + 2 H2O → CuSO4 (aq) + Mg(OH)2 (s) + H2 (g)

I hope you have enjoyed reading my postings!

Reaction by YOSF

Reaction #3 - Making sodium hydroxide

Sodium hydroxide is a well-known strong base (an alkali). It is corrosive (yes, not only acids are corrosive) and is commonly involved in chemical reactions.

Below are a few ways to make sodium hydroxide:

Sodium metal + Water → Sodium hydroxide + Hydrogen gas
2 Na (s) + 2 H2O (l) → 2 NaOH (aq) + H2 (g)

Sodium ethoxide + Water → Sodium hydroxide + Ethanol
NaC2H5O (s) + H2O (l) → NaOH (aq) + C2H5OH (l)

Sodium metal + Lithium hydroxide → Sodium hydroxide + Lithium
Na + LiOH → NaOH + Li

These methods work quite well, but be careful: Sodium metal is highly reactive and will react violently and with so much heat that the hydrogen gas given off (during the first reaction) might ignite. In the second reaction, sodium ethoxide and water react violently. For the third reaction, the by-product, lithium metal will also, quickly and violently, react with excess water. So you might end up with a mixture of lithium hydroxide and sodium hydroxide.

Reaction by YOSF

Monday, November 29, 2010

Reaction #2 - Making manganese(II) carbonate

This is a demonstration of a precipitation reaction.

Manganese(II) sulfafte + Sodium carbonate →
Manganese(II) carbonate (precipitate) + Sodium sulfate
MnSO4 (aq) + Na2CO3 (aq) → MnCO3 (s) + Na2SO4 (aq)

Light pink manganese(II) carbonate precipitate is formed by this reaction.

Reaction by YOSF

Theory #1 - Making of sulfur

It is known that sodium bisulfate and sodium thiosulfate react to form sulfur, making a foul-smelling stench.

This is what I think is the chemical reaction:

Sodium bisulfate + Sodium thiosulfate →
Sodium bisulfite + Sodium sulfate + Sulfur
8 NaHSO4 + 8 Na2S2O3 → 8 NaHSO3 + 8 Na2SO4 + S8

Theory by YOSF

Reaction #1 - Making sulfuric acid with simple reagents

Magnesium + Water → Magnesium hydroxide (milk of magnesia) + Hydrogen
Mg + 2H2O → Mg(OH)2 + H2

Lead the hydrogen gas into copper sulfate solution...

Copper sulfate + Hydrogen → Sulfuric acid (oil of vitriol) + Copper
CuSO4 + H2 → H2SO4 + Cu

This is how you can get sulfuric acid (um, and copper) from magnesium, copper sulfate and some water!!!

Reaction by GITS

Introduction

Dear readers,

Welcome to our blog!

This blog is to show our chemistry theories, regardless of being about redox reactions or just the chemical structure.

Please comment and state your ideas. Thanks!

Yours faithfully,
GITS & YOSF Company