| What exactly is the pH Scale? Where is Neutral? | -This is simply a Scale that ranges from 0-14, and can say how Acidic or Alkaline a Solution is
-Neutral is spot on 7 |
| pH of Acid? What do they make in Water? | -Acids have a pH with less than 7
-Acids make H+ Ions |
| pH of Base and Alkaline? What's the Difference between them 2? What's do they make in Water? | -Bases and Alkaline has a pH of greater than 7
-Alkaline is simply a Base that can Dissolve in Water.
-They make a OH- Ion in Water [Hydroxide Ions] |
| What does it mean if the Value of the pH is Inversely Proportional to the Concentration of Hydroxide Ions? | -This just simply means if the Concentration of Hydrogen Ions Increase, the pH will Decrease.
-This makes sense, because Higher Concentration of Hydrogen Ions makes it more Acidic, and they Lower the pH |
| What is an Indicator? | -This is simply a Dye that Changes Colour if its Above or Below a certain pH |
| What is the Universal Indicator? Why is it useful? | -The Universal Indictor is a Combination of Dyes, and can be useful to Estimate the pH of a Solution.
-Simply add a Few Drops, and it changes Colour. [If its the right pH] This is for all Indictors |
| Describe the pH Scale, from 0-14 | 0= Very Acidic. Red
3-Quite Acidic. Orangey-Red
6=Little Acidic. Yellow
7=Neutral. Green
8=Weak Alkaline. Faint Blue
11=Quite Alkaline. Light Purple
14=Very Alkaline. Dark Purple |
| What can a pH Probe, attached to a pH Meter do? Why is it Useful? | -This simply measures the pH Electronically
-The Probe is in the Solution, and the pH appears Digitally
-This can give Higher Levels of Accuracy [As Colour can't give Full Answers]
-Its important to Calibrate it Properly, and makes sure its Washed with Deionised Water. |
| What is the reaction called between Acids and Bases? What do they Make [Products?]
-Give an Example | -This reaction is called a Neutralisation
-They make a Salt and Water
-In terms of the Ions, its Water
-HCl + NaOH --> NaCl + H²O
[Acid] [Alkali] [Salt] [Water]
-H+ + OH- ---> H²O |
| So what happens if a Acid Neutralises a Base? What will the Product be? How can it be Shown? | -The Product will be Neutral, pH of 7.
-When its that, the Concentration of Hydrogen Ions [H+] is the same as the Hydroxide Ions [OH-]
-Indicator can be used to visualise that the Reaction has Happened |
| What is a Titration? What is a Titration Curve? What does the Vertical Line show? | -This is simply working how much Acid is needed to Neutralise a Base of an Unknown Concentration [Opposite is True]
-The Titration Curve is simply showing where Neutralisation has Happened.
-When its Vertical, the pH of the Solution has hit 7
-This is the End Point of the Titration |
| What do Acids to in Water exactly? Examples with HCl and HNO³ | -They Ionise- Make Hydrogen Ions
-HCl ---> H+ + Cl-
-HNO³ ---> H+ + NO³- |
| What does a Strong Acid mean? Examples | -Simply means they almost Completely Ionise in Water
-Large Percent dissociate to release H+ Ions. This can give Low pH
-Sulfuric, Hydrochloric and Nitric Acids |
| What does a Weak Acid mean? Examples | -Simply means they don't fully Ionise in the Solution
-Small Percent dissociate to release H+ Ions. This can give pH of 2-6
-Ethanoic, Citric and Carbonic Acids |
| Are Weak Acids Reversible? What does this mean? | -Yes they can be Reversed, due to a small amount Releasing H+ Ions
-This makes an Equilibrium Mixture [Reversible Mixture] |
| So what can Acidic Strength tell you? | -This can just say How much of the Acid Ionise in the Water |
| What does the Concentration of an Acid mean? | -This just says how much Acid there is in a Litre, or 1dm³
-Concentration can mean how Watered down your Acid is |
| What does it mean if an Acid has a High Proportion of Acid Molecules, against the Volume of Water? Opposite [Low Proportion] | -This means its Highly Concentrated, in terms of the High Proportion
-This means its Dilute, in terms of the Low Proportion |
| What does the Concentration describe? Terms of Acid | -This simply says the Total Number of Dissolved Acid Molecules
-Not the Number of Molecules that make Hydrogen Ions |
| What is amount of Concentration of H+ to make the pH Decrease by 1?
3? | -This decreases by a Factor of 10
-For 1, it would just be 10
-For 3, it would be 1000 [10 x 10 x 10] |
| What can happen if a Metal reacts with an Acid?
Examples with Hydrochloric Acid, Sulfuric Acid and Nitric Acids. | -A Salt and Hydrogen is made from this
Hydrochloric Acid:
2HCl + Mg ---> MgCl² + H² [Makes Magnesium Chloride]
6HCl + 2Al ---> 2AlCl³ + 3H² [Makes Aluminium Chloride]
Sulfuric Acid:
H²SO⁴ + Mg --> MgSO⁴ + H² [Makes Magnesium Sulphate]
3H²SO⁴ + 2Al ---> Al²(SO⁴)³ + 3H² [Makes Magnesium Sulphate]
Nitric Acid makes Nitrate Salts, but its even more Complicated
The other products are either
H²O, NO, NO² Balancing the equation is pretty tricky to Guess |
| What happens when a Metal Carbonate reacts with an Acid?
-Example with Hydrochloric Acid and Sodium Carbonate
-Example with Sulfuric Acid and Potassium Carbonate
-Example with Nitric Acid and Zinc Carbonate | -A Salt, Water and Carbon Dioxide is made
2HCl + Na²CO³ ---> 2NaCl + H²O + CO² [Sodium Chloride Made]
H²SO⁴ + K²CO³ ---> K²SO⁴ + H²O + CO² [Potassium Sulphate]
2HNO³ + ZnCO³ ---> Zn(NO³)² + H²O + CO² [Zinc Nitrate Made] |
| What happens when:
Hydrochloric Acid reacts with Sodium Hydroxide
Sulfuric Acid reacts with Zinc Hydroxide
Nitric Acid reacts with Potassium Hydroxide | -HCl + NaOH --> NaCl +H²O [Sodium Chloride is made]
-H²SO⁴ + Zn(OH)² ---> ZnSO⁴ + 2H²O [Zinc Sulphate is made]
-HNO³ + KOH ---> KNO³ + H²O [Potassium Nitrate is made] |
| How can Soluble Salts be Made? What's difficult with making them?
[Made via Acid and Alkali] | -Simply to React an Acid, with an Alkali
-However, its hard to tell when the Reaction has Finished.
-You also can't just add Excess Alkali to the Acid, and Filter out what's left, because the Salt is Soluble and would be interfered with the Excess |
| Explain an Practical that can make Soluble Salts [With acid and Alkali] | -First react a Acid with an Alkaline
-This reaction has to had a Titration prior to this, to make sure the Right Amount of Alkali is put in to Neutralise it
-Then, let them react. No Indicator is needed because you know the Volumes needed, so the Indicator won't affect the Salt
-The Solution left when the Reaction is done with have the Salt and the Water. Slowly evaporate some of the Water, and then let the Solution to Crystallise. Filter of the Solid and then Dry it.
-Your end product will be a Pure, dry Salt |
| How can you make Soluble Salts, with an Acid and Insoluble Reactant? [Base] | -First, pick the Correct Acid and Metal/Insoluble Base
-Put the Base in the Acid, and it will react to make a Soluble Salt plus Water
-When all the Acid has been Neutralised, the Excess Solid will sink to the Bottom of the Flask [Heating up the Flask can help the Reaction]
-Finally filter off the Excess Solid to gain a Solution with Salt and Water
-Then Heat your Solution gently, to evaporate some of the Water. Then let it cool off and have it Crystallise. Filter the Solid off, and let it Dry
[Example can be Copper Oxide to Hydrochloric Acid making Copper Chloride] |
| How can you make an Insoluble Salt? How can you het Lead Chloride [Insoluble] | -Simply do a Precipitation Reaction
-That may sound confusing, but just pick 2 Soluble Salts, which react that can result in gaining the Insoluble Salt
-Lead Chloride can be achieved by mixing Lead Nitrate and Sodium Chloride [Both are Soluble]
-Also Lead Chloride will be accompanied with Sodium Nitrate |
| Explain how you can get Lead Chloride [An Insoluble Salt] | 1. First add some Lead Nitrate to a Test Tube. Then add Deionised Water to Dissolve it. Do the same with Sodium Chloride in another Test Tube
2. Put both Solutions in a Small Beaker, and give a Stir to mix them. The Lead Chloride should Precipitate out [You can See it]
3. Put your Solution through Filtration
4. Then put Lead Chloride into fresh Filter Paper, to let it Dry |
| What's Special with Deionised Water? | -Its simply Water, with no Ions involved |
