Acids and Bases Flashcards
(24 cards)
What is the pH scale?
The pH scale measure the acidity or alkalinity of a solution
Some examples of acidic solutions
Sugary water
Tea tree and mint shampoo
Vitamin C
Lemon juice
Vinegar
Bee sting
Some examples of neutral solutions
Salt water
Easy iron spray
Wasp sting
Water
Some examples of alkali solutions
Ariel washing powder
Dish water tablets
Bleach
What are alkalis and what is an alkaline solution?
Soluble bases and an alkaline solution can be formed when a metal oxide is dissolved in water vice versa
Why do acidic and alkaline solutions conduct electricity?
Because they have ions that are free to carry charge
What is the normal and ionic formula for hydrochloride acid, sulfuric acid and nitric acid?
Hydrochloric: HCl H+(aq) + Cl-(aq)
Sulfuric acid: H2SO4 2H+(aq) SO42-(aq)
Nitric acid: HNO3 H+(aq) NO3-(aq)
What is the normal formula for lithium hydroxide, calcium hydroxide and sodium hydroxide?
Lithium hydroxide: LiOH
Calcium hydroxide: Ca(OH)2
Sodium hydroxide: NaOH
How does the conductivity change?
The more concentrated the solution the better it conducts
What type of reaction is that he breakdown of water molecules and what is produced?
It is an equilibrium/reversible reaction and they break up into hydrogen ions and hydroxide ions
What is equilibrium?
The state reached by a reaction mixture when the rates of forward and reverse reactions have become equal
What must all aqueous solutions contain?
Both H+ and OH- Iona
What is neutralisation?
Neutralisation is the reaction of an acid or alkali with a base that results in the pH moving towards 7
What are the equations for neutralisation?
Acid + Alkali (Metal Hydroxide) = Salt + Water
Acid + Metal Oxide = Salt + water
Acid + metal carbonate = salt + water + carbon dioxide
What is a base?
Bases are substances which neutralise acids, Reid,ting in the pH of the acid increasing towards 7 and water being produced
What are the three most common acids?
Hydrochloric acid: HCl
Sulfuric acid: H2SO4
Nitric acid: HNO3
How to name a salt?
Alkali to from acid to back
What are the three slay name ending?
Chloride
Sulfate
Nitrate
What is a spectator ion?
spectator ions are ions which are present during a reaction but are unchanged by the reaction.
What is a titration?
A titration experiment is carried out to accurately measure the volume of the substances that react in a chemical reaction.
What is concord at results?
Results within 0.2cm3 of each other.
What happens with the rough titration?
It is not included in calculations
What equipment is required for titrations?
A Burette, conical flask, Pipette, Pipette filler, indicator
How do you carry out a titration?
- If the sample is a solid, it is weighed using an accurate balance, and then dissolved to make up a known volume of solution (usually 100cm3)
- A Pipette is used to measure accurately a volume of this solution e.g. 10cm3. A safety Pipette filled is used to draw solution into the Pipette . This is emptied into the comical flask.
- A few drops of indicator may be added to the conical flask. This will show a change of colour when the titration is complete.
- A second chemical is placed in a burette. This other solution is of a. He iCal that will react with the synthesised chemical sample in the conical flask. Often the solution in the burette is an acid of a precise, known concentration.
- The solution from the burette is run into the conical flask. The solution is added one drop at a time, with swirling to mix the solutions as the end-point approached. Eventually, a colour change shows that the correct amount has been added to react completely with the synthesised chemical in the sample.
- The volume of solution added from the burette is noted. The titration results can then be used to calculate the amount of synthesised chemical in the sample, and therefore find its purity.
- You can then use your concordat results to calculate the average titration.
