Summary
Summary Notes for GCSE Chemistry Acid, Bases, Salts and Neutralisation
- Course
- Institution
Notes for GCSE Chemistry Acid, Bases, Salts and Neutralisation
[Show more]
Seller
Follow
Taylorsnotes
Content preview
Taylor’s Notes Acids, Bases, Salts and NeutralisationIndicators
Indicator Colour in Acid Solution Colour in Alkaline Solution
Litmus Red Blue
Phenolphthalein Colourless Pink
Methyl Orange Orange Yellow
Acids
Acids are a source of hydrogen ions
Acid + Base Salt + Water
Acid + Metal Oxide Salt + Water
Acid + Metal Salt + Hydrogen
Acid + Metal Carbonate Salt + Water + Carbon dioxide
Bases
Bases are acceptors of H+ ions They can be insoluble (bases) or soluble (alkalis)
An alkali is a soluble bases and are a source of hydroxide ions, OH-
Solubility Rules
All common sodium, potassium and ammonium salts are soluble
All nitrates are soluble
Chlorides are soluble except silver chloride and lead chloride
Sulphates are soluble except barium, calcium and lead
Carbonates are insoluble except sodium, potassium and ammonium
Hydroxides are insoluble except sodium, potassium and ammonium, calcium is only slightly soluble
Salt Preparation by Excess Base
Excess base is used when an insoluble base reacts with an acid to form a soluble salt
1. Add base to an acid and stir and heat until excess base remains unreacted at the bottom of the beaker
2. Filter the mixture to remove the excess base as residue on the filter paper
3. Collect the filtrate in an evaporating basin
4. Perform a crystallization
Salt Preparation by Precipitation
Insoluble salts are prepared in precipitation reactions, using two soluble solutions to produce an insoluble salt. This is done by matching the
positive and negative ions in the starting materials.
Barium sulphate for example: Ba(NO3)2(aq) + Na2SO4(aq) → BaSO4(s) + 2 NaNO3(aq)
Precipitation is used when two solutions of soluble substances react to form an insoluble salt
1. Mix together two solutions of soluble substances
2. A precipitate of the insoluble salt forms
3. Filter the mixture and keep the residue
4. Wash the residue with distilled water
5. Allow the solid to dry in a warm place with no direct heating
Salt Preparation by Titration
A titration is used when two solutions of soluble substances react to form a soluble salt
1. Fill a burette with a chosen acid up to the 0.00 mark
2. Add 25.0 of alkali to a conical flask using a pipette
3. Add an appropriate indicator to the conical flask
4. Add acid drop by drop to the alkali whilst swirling until a colour change is observed
5. Repeat steps 1) to 4) until concordant results are obtained
6. Repeat steps 1) to 4) without indicator using the volume recorded and perform a
crystallisation
Universal Indicator isn’t used in a titration as it does not give a specific distinct colour change
Crystallisation
1. The salt solution is placed in an evaporating basin
2. The solution is heated until a saturated solution form
3. The solution is not heated to dryness to prevent the thermal decomposition of the salt formed
4. A solution is saturated when a cold glass rod dipped in forms crystals of the salt on the tip
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller Taylorsnotes. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $6.51. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
75323 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now