AQA GCSE Chemistry: Chemical Analysis

In chromatography, the mobile phase is the ______.

• A) absorbent paper

• B) solvent

• C) stationary phase

• D) ink

Which of the following is an example of a pure substance?

• Coffee

• Orange juice

• Distilled water

• Air

What is the stationary phase in paper chromatography?

• Solvent

• Chromatography paper

• Mobile phase

• Ink

What does Rf value represent in chromatography?

• Distance travelled by solvent

• Distance travelled by substance

• Ratio of distances travelled by substance and solvent

• Time taken for separation

What is an example of a formulation? (Choose all correct answers)

• Paint

• Air

• Medicine

• Salt Water

• Ketchup

Elements are made up of ______.

• compounds

• mixtures

• one type of atom

• different substances

What is the first step in the paper chromatography process?

• Using a pipette to apply ink

• Measuring the distance traveled by the solvent

• Using a pencil and ruler to measure 2cm from the bottom of the paper

• Placing the chromatography paper into the solvent

What color precipitate is produced when sodium hydroxide is added to Al³⁺ ions?

• White

• Blue

• Green

• Brown

What charge does Copper (II) have?

• 2+

• 1+

• 2-

• 1-

Fill in the blank: The precipitate formed when Mg²⁺ ions react with NaOH is ______.

• White

• Blue

• Green

• Brown