Q 01/05

Which of these acids, sprayed by ants to defend their nests, is named after the Latin for 'ant'?

A) Butyric acid

B) Formic acid

C) Tannic acid

D) Uric acid

Answer · why

B) Formic acid

Formic acid takes its name from formica, the Latin for ant. English naturalist John Ray first isolated it in 1671 by distilling large numbers of the i...

Q 02/05

Which alchemists' mixture of two acids can dissolve gold, although neither acid manages it alone?

A) Aqua regia

B) Aqua vitae

C) Oil of vitriol

D) Aqua tofana

Answer · why

A) Aqua regia

Aqua regia once hid two Nobel medals: in wartime Copenhagen, George de Hevesy dissolved them in it to keep the gold from the Nazis, then recovered the...

Q 03/05

Søren Sørensen devised the pH scale while he was head of the research laboratory of which brewery?

A) Heineken

B) Budweiser

C) Carlsberg

D) Tuborg

Answer · why

C) Carlsberg

Carlsberg employed Sørensen to study how hydrogen ions affect proteins, and he wanted a simple way to express their concentration. The same laboratory...

Q 04/05

Which vegetable's juice is a homemade pH indicator, pink in acids and yellow in strong bases?

A) Cauliflower

B) Spinach

C) Sweetcorn

D) Red cabbage

Answer · why

D) Red cabbage

Red cabbage owes the trick to its anthocyanin pigment, which is magenta in acids, purple at the midpoint and shifts through blue towards yellow as a s...

Q 05/05

Which garden shrub acts as a living pH test, blooming blue in acidic soil and pink in alkaline soil?

A) Rhododendron

B) Camellia

C) Lavender

D) Hydrangea

Answer · why

D) Hydrangea

Hydrangea flowers turn blue only when acidic soil frees aluminium ions for the roots to absorb. Alkaline ground ties the metal up, so the same plant b...