Oquizy

John is heating ethanol with a Bunsen burner. What is the most important safety precaution?

Boil it quickly for accuracy Use a strong tripod Use a water bath Wear cotton gloves

What is the purpose of chromatography in a purity test?

To determine the number of components in a mixture To extract a colourless compound To measure melting point To separate a solid from a liquid

What is this setup used for?

Chromatography Measuring melting point Separating a solvent from a solution Separating solids from liquids

Why is a locating agent used in chromatography?

To keep the spots from moving To remove impurities To see colourless substances To speed up separation

What is happening during the first horizontal section?

The substance is boiling The substance is cooling The substance is melting The thermometer is faulty

Two substances (X and Y) were tested in the same solvent. Rf of X = 0.25, Rf of Y = 0.85. Which conclusion is correct?

X is less soluble in this solvent X is more soluble Y is less soluble Y remained at the baseline

If a different solvent is used in chromatography, what happens to the Rf values?

All Rf values increase Rf values decrease to zero Rf values may change depending on solubility Rf values remain unchanged

Why must the solvent front be marked immediately after removing the chromatogram?

It helps identify unknown compounds Paper will tear during drying Solvent continues to evaporate, altering results Spots will dissolve again

Quiz: Chemistry - Experimental Chemistry