What do acids release?
H+ ions
What do bases release?
OH- ions
What is an alkali?
A soluble base, that can neutralise acids.
What is a strong acid?
An acid that completely dissociates in an aqueous solution.
What is a weak acid?
An acid that only partially dissociates in an aqueous solution.
How work out an ionic equation?
1) Write our normal equation with charges
2) Cross out repeating compounds
3) This leaves you with you compound.
What does acid + base form?
Salt + water
What does salt + carbonate base form?
Salt + water + carbon dioxide
How to make up a standard solution for volumetric analysis?
- Weigh out 1g of sodium hydroxide into a weighboat using a mass balance
- Put the sodium hyrdroxide into your beaker and add 75cm^3 (volume of water in volumetric flask doesn’t go over the meniscus) of distilled water (avoid any ions in tap water to intefere) to the beaker
- Rinse the weighboat with the distilled water into the beaker to ensure all the sodium hydroxide is in solution
- Stir the solution with a glass rod (avoid spatula reacting) until the NaOH has completely dissolved. It should be dissolved when there is no solid left anf the liquid is clear
- Then, add your solution to volumetric flask and rinse your beaker and glass rod into flask to ensure all NaOH has been added
- After top up your volumetric flask with distilled water to the graduated line on the flask, ensuring you are eye level with the meniscus
- Next, put the lid on your volumetric flask and invert it a couple times to ensure it is all homogenous
What is the method for titrations?
a
How to calculate the concentration of a diluted solution?
1) Divide the volume of the stock solution used by the final volume of diluted solution made
2) Multiply this number by the concentration of stock solution used
How to calculate the volume of concentrated stock solution needed?
1) Work out the dilution factor by dividing the concentration of the stock solution by the concentration of the diluted solution required
2) Divide the final volume required by the dilution factor; this is the volume of stock solution needed
3) The difference between the volume of stock solution and the final volume of the dilute solution is how much solvent to add
Describe an accurate method to dilute a concentrated solution
1) Transfer the required volume of stock solution to a suitable volumetric flask using a pipette
2) Carefully add solvent to the flask until the bottom of the meniscus touches the calibration mark on the neck of the volumetric flask
3) Stopper the volumetric flask and shake to ensure the solution is thoroughly mixed
How to calculate a titration?
e
