titration

What is a standard solution

A solution with a known concentration

Other name for a standard solution

Volumetric solution

How do you create a standard solution

Dissolving a known amount of solid in a known amount of distilled water to create a known concentration

How do you know how much of a solids you need

Work out the number of moles you need by doing concentration times volume and then figure out the mass by doing moles times relative mass

How can you ensure you got the exact mass of the solid

After you've weighed it in a weighing boat on a digital balance and tipped it into a beaker re-weigh the boat which may contain some solid residue and take away the mass of the boat from the mass of the solid and the boat

What should you put your solution in

A volumetric flask

How can you ensure that after dissolving the solid in distilled water in the Beaker you have gottenall of it into the volumetric flask

Use a funnel and rinse Beaker and stirring rod with distilled water and add to this to the flask to and then just top it up until the meniscus reaches the volume line

What mistake could you make

If you don't go drop by drop you could add too much and have to restart

How do you mix it

Stopper the volumetric flask and tip it upside down to ensure mixing

When titrating what should you use to accurately measure a set volume of the solution into your flask with your indicator

A pipette

How should you fill the burette with your standard solution of acid

Use a funnel and bring it just below Eye Level to avoid splashing into eyes and wear safety glasses

When you are doing your accurate titration after your rough titration how should you finish it off and why

Go drop by drop so you don't overshoot and reduce accuracy

How do you figure out the volume of titre

Initial reading - final

What should you do once you've done one accurate titration

Repeat until you have at least three concordant results and leave out anomalies and calculate a mean

What are the two most common indicators for titration

Methyl orange and phenolphthalien

What is the colour change of methyl Orange

Red in acid

yellow in alkai

What is the colour change of phenolphthalien

Colourless in acid

Pink in alkali

Why do we use specific indicators for titration

The change colour quickly over a small pH range so you know exactly when the reaction is ended

Why do we not use universal indicator

Colour changes too gradual

How can we make our colour change clearer

Putting flask over white tile