Chemistry Quiz

What is the chemical formula of common salt?

• KCl
• NaCl
• NaHCO3
• CaCl2

Answer: NaCl. Common salt is sodium chloride, NaCl. NaHCO3 is baking soda, and KCl is sold as a low-sodium salt substitute.

Which gas puts the fizz in a bottle of cola?

• Oxygen
• Nitrogen
• Carbon dioxide
• Hydrogen

Answer: Carbon dioxide. Carbon dioxide is dissolved into the drink under pressure. Open the cap, the pressure drops, and the gas comes out as bubbles.

The symbol Fe comes from the Latin word 'ferrum'. Which element does it stand for?

• Iron
• Fluorine
• Francium
• Lead

Answer: Iron. Fe is iron. Lead's symbol, Pb, also comes from Latin (plumbum), which is where the word 'plumber' comes from.

Which gas gives the red-orange glow in the classic glass-tube signs outside shops?

• Argon
• Helium
• Xenon
• Neon

Answer: Neon. Neon glows red-orange when electricity passes through it. Other colours in 'neon' signs usually come from other gases or coated tubes.

Antacid tablets ease acidity in the stomach because they contain...

• a mild base, such as magnesium hydroxide
• an acid, such as citric acid
• a sugar, such as glucose
• a salt, such as sodium chloride

Answer: a mild base, such as magnesium hydroxide. Acidity means too much hydrochloric acid in the stomach. A mild base such as magnesium hydroxide (milk of magnesia) neutralises it, forming a salt and water.

What is the IUPAC name of CH3-CH2-OH?

• Methanol
• Ethanal
• Ethanol
• Propanol

Answer: Ethanol. Two carbon atoms give the prefix 'eth-', and the -OH group gives the ending '-ol': ethanol. Ethanal (CH3CHO) is an aldehyde, a common mix-up in organic chemistry MCQs.

Which is the general formula of the alkanes?

• CnH2n
• CnH2n+2
• CnH2n-2
• CnHn

Answer: CnH2n+2. Alkanes have only single bonds, so they hold the most hydrogen possible: CnH2n+2, as in methane (CH4) and ethane (C2H6). CnH2n is for alkenes and CnH2n-2 for alkynes.

In 1898 the Curies named a new radioactive element after Marie Curie's homeland, which was then split between Russia, Germany and Austria. Which element?

• Radium
• Curium
• Francium
• Polonium

Answer: Polonium. Polonium is named after Poland. At the time Poland was partitioned and did not exist as an independent state, and the name drew attention to that.

August Kekulé said a daydream of a snake seizing its own tail gave him the ring structure of which compound?

• Benzene
• Methane
• Glucose
• Ethylene

Answer: Benzene. Kekulé told the story in 1890, recalling his work on benzene (C6H6), whose six carbon atoms form a ring. Historians still argue over whether the dream really happened.

A form of carbon, C60, is shaped like a football and was named after an American architect famous for geodesic domes. What is it called?

• Graphene
• Diamond
• Buckminsterfullerene
• Graphite

Answer: Buckminsterfullerene. C60 has 12 pentagons and 20 hexagons, like a football. Its discoverers, Kroto, Curl and Smalley, named it after Buckminster Fuller and shared the 1996 Nobel Prize in Chemistry.