WJEC AS Level Chemistry: Unit 1 Review

This set of flashcards covers key terms and concepts related to standard solutions, titration, and primary standards in WJEC AS Level Chemistry.

Standard Solution

A solution whose concentration is accurately known, often prepared using a primary standard.

Primary Standard

A reagent that is pure, stable, has low hygroscopicity, and high molar mass, allowing for accurate weighing.

Titration End Point

The point in titration when the indicator changes color, indicating a visible signal but not necessarily complete reaction.

Equivalence Point

The point in a titration at which the number of moles of acid equals the number of moles of base.

Acid-Base Indicator

A substance that changes color at a particular pH level to signify the completion of a reaction.

Dilution

The process of reducing the concentration of a solute in solution, typically by adding more solvent.

Mass Calculation for Standard Solution

The formula used is m = n imes M, where n is the number of moles and M is the molar mass.

Conical Flask

A laboratory glassware used to hold liquids during titration and features a narrow neck to facilitate mixing.

Burette

A graduated glass tube used to dispense precise volumes of a liquid during titration.

Pipette

A laboratory tool used to transport a measured volume of liquid, often used to deliver solutions into a conical flask.

Na2CO3

Anhydrous sodium carbonate; used as a primary standard for titrations.

Phenolphthalein

An acid-base indicator that is colorless in acidic solutions and pink in alkaline solutions.

Methyl Orange

An acid-base indicator that is red in acid solutions and yellow in alkaline solutions.