Question 1
Which mixture can paper chromatography separate?
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Dyes dissolved in a solvent
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Sand suspended in water
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Oil floating on water
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Iron mixed with sulfur
Question 2
In paper chromatography, the solvent is called the?
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Mobile phase
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Stationary phase
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Catalyst phase
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Indicator phase
Question 3
In paper chromatography, the paper is the?
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Stationary phase
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Mobile phase
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Reactant phase
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Gas phase
Question 4
Why is a chromatography baseline drawn in pencil?
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Graphite does not dissolve in the solvent
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Graphite moves ahead of the solvent front
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Graphite reacts with the sample spots
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Graphite makes every spot travel farther
Question 5
Which interpretation is most likely when a sample gives one chromatogram spot?
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One pure substance
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Several separated dyes
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An element rather than a compound
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A gas rather than a liquid
Question 6
If a sample gives several spots on a chromatogram, it is likely to be?
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A mixture
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A pure compound
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A catalyst
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A neutral solution
Question 7
What is the test for oxygen gas?
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A glowing splint relights
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A lit splint gives a squeaky pop
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Limewater turns milky
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Damp red litmus turns blue
Question 8
What is the test for hydrogen gas?
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A lit splint gives a squeaky pop
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A glowing splint relights
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Limewater turns milky
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Orange bromine water decolourises
Question 9
What is the test for carbon dioxide gas?
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Limewater turns milky
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A glowing splint relights
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A lit splint gives a pop
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Damp blue litmus turns red
Question 10
Which gas bleaches damp litmus paper?
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Chlorine
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Hydrogen
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Oxygen
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Nitrogen
Question 11
What colour is universal indicator in a strong acid?
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Red
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Green
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Blue
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Purple
Question 12
What colour is universal indicator in a neutral solution?
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Green
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Red
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Blue
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Orange
Question 13
How would you classify a solution with pH 2?
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Strongly acidic
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Neutral
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Weakly alkaline
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Strongly alkaline
Question 14
How is a solution with pH 11 classified?
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Alkaline
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Strongly acidic
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Weakly acidic
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Neutral
Question 15
What does the symbol equation \(\mathrm{HCl} + \mathrm{NaOH} \to \mathrm{NaCl} + \mathrm{H}_2\mathrm{O}\) represent?
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Neutralisation
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Combustion
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Thermal decomposition
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Displacement
Question 16
Why compare an unknown chromatogram with known standards?
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To identify substances by matching spot positions
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To count substances from the solvent colour
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To identify substances from paper length
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To change how far the unknown spots travel
Question 17
Why must chromatography samples start above the solvent level?
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So they do not dissolve into the solvent reservoir
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So the solvent cannot rise through the paper
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So every dye travels at the same speed
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So the baseline moves with the solvent
Question 18
What is the solvent in a solution?
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The substance that dissolves the solute
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The substance that is dissolved
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The solid left after filtration
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The liquid collected after condensation
Question 19
How is a solution with pH 7 classified?
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Neutral
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Strongly acidic
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Weakly acidic
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Strongly alkaline
Question 20
Which method separates oil from water?
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A separating funnel
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Paper chromatography
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Simple distillation
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Evaporation to dryness
Question 21
Why do dyes separate during paper chromatography?
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They differ in solubility and attraction to paper
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They have identical solubility and attraction
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They react to make new dyes
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They contain different numbers of protons
Question 22
What is a pure substance?
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One element or one compound
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Two elements mixed in any proportion
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A compound dissolved in water
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Several compounds blended together
Question 23
What does a sharp melting point usually indicate?
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A pure substance
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A mixture of substances
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An impure metal sample
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A solution containing a solute
Question 24
Which mixture can filtration separate?
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Sand and water
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Salt dissolved in water
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Ethanol mixed with water
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Two gases mixed together
Question 25
What can evaporation obtain from a solution?
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The dissolved solid
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The collected solvent
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An insoluble residue
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A mixture of gases
Question 26
Which mixture can simple distillation separate?
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Water from salt solution
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Sand from water
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Iron from sulfur
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Dyes in black ink
Question 27
What is crystallisation used to obtain?
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Pure solid crystals from a solution
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An insoluble solid by filtration
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A solvent collected by distillation
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Dyes separated on paper
Question 28
What is the residue in filtration?
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Insoluble solid left on the filter paper
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Liquid that passes through the filter paper
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Dissolved solid carried through the filter
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Water used to wash the filter paper
Question 29
What is the filtrate in filtration?
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Liquid that passes through the filter paper
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Insoluble solid left on the filter paper
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Filter paper after it has dried
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Mixture before it enters the filter
Question 30
Why are crystals dried after crystallisation?
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To remove solvent left on their surfaces
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To dissolve them back into the solution
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To increase their size after filtering
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To change them into a new compound