Busy. Please wait.

show password
Forgot Password?

Don't have an account?  Sign up 

Username is available taken
show password



Already a StudyStack user? Log In

Reset Password
Don't know
remaining cards

Pass complete!

"Know" box contains:
Time elapsed:
restart all cards

  Normal Size     Small Size show me how

Volumetric Analysis1

Volumetric Analysis: Acid/Base

Branch of chemistry to which volumetric analysis belongs? Quantitative Analysis
Solute A substance that will dissolve in a solvent
Solvent A solvent is a liquid in which a solute will dissolve.
Solution A solution is a perfect mixture of a solute and a solvent
Concentration The concentration of a solution is the amount of solute that is dissolved in a given amount of solvent
Weight/weight This is the amount of solute dissolved in 100g of water
Weight/volume This is the amount of solute dissolved in 100cm of water
Volume/volume This is the amount of solute mixed with 100cm of water
Moles/Litre A 1 molar solution is one that contains 1 mole of a substance in one litre of water.
ppm Parts per million. Also known as 1mg/litre
Standard Solution A standard solution is a solution of known concentration
Primary Standard A primary standard is a chemical used to make a standard solution.
4 criteria of a a substance to be called a primary standard 1: It must be available in a highly pure state 2: It must be stable in air. 3: It must dissolve readily in water 4: It should have a high molecular mass to allow for easy weighing and to minimise percentage error
Why is Sulphuric Acid NOT considered a primary standard? It absorbs moisture from the air
Important steps when filling a volumetric flask? 1: Rinsed with water. 2: Filled with a wash bottle to 1cm of the mark 3: Using a dropper at eye level fill the flask until the bottom of the meniscus sits on the line. 4: Stopper and invert 20 times.
Why do we never pipette directly from the volumetric flask? The pipette may contain some impurity that may contaminate the entire sample. We always pour some of the solution into a beaker before pipetting.
Important steps when using a pipette? 1: Never pipette by mouth, always use a pipette filler 2: Rinse with water, then the solution it will contain. 3: Fill the pipette until the bottom of the meniscus sits on the line. 4: Do not blow out the last drop, the pipette is calibrated for this.
Important steps when using a burette? 1: Clamp vertically in the retort stand. 2: Fill at eye level with a white tile/card behind the burette. 3: Using a funnel and then a dropper fill the burette until the bottom of the meniscus sits on the line.
Why does the burette normally contain acid and not a base? Bases can crystalise as they dry and clog the taps of burettes. For this reason the base is normally placed in the pipette.
Why is a conical flask used instead of a beaker? The conical flask allows the solution to be swirled without the risk of spilling. Beakers cannot allow this.
Why is the conical flask placed on a white tile? The white tile allows colour changes to be more easily seen.
Hydrochloric Acid Vs Sodium Carbonate: Indicator and colour change? Methyl Orange: Yellow to Pink
Sodium Hydroxide Vs Hydrochloric Acid: Indicator and colour change? Methyl Orange: Yellow to Red
Sodium Hydroxide Vs Ethanoic Acid: Indicator and colour change? Phenolphthalein. Colourless to pink. The base is placed in the burette and the acid in the concial flask. This is because it is easier to see a colourless to pink colour change than pink to colourless.
Washing Soda (Sodium Carbonate Crystals) Vs Hydrochloric Acid: Indicator and colour change? Methyl Orange: Yellow to Pink
When using the volumetric analysis formula what is concentration calculated in? The answer is always calculated in moles/Litre at the end as moles/Litre was used at the start!
Created by: cbschemistry