QUARTER FINAL STAGE 2024
QUARTER FINALS STAGE, ROUND 5 (RIDDLES)
Ghana National College: 46 points
Opoku Ware School: 45 points
Aburi Presbyterian Senior High Technical School: 35 points
ROUND 5 - RIDDLE
RIDDLE
I am a straight chain carboxylic acid.
I am found naturally in various dairy products such as cheese and butter.
I am one of the main contributors to the strong scent of male goats.
My common name is derived from the Latin word for goat, "caper." My empirical formula is the molecular formula for propanal.
ANSWER: Hexanoic acid
EXPLANATION:
Hexanoic acid, CH3(CH2)4COOH (C6H12O2), is commonly called caproic acid, from the Latin "caper" (goat), reflecting its presence in goat fat and its contribution — alongside related acids — to the characteristic goaty odour of dairy products like cheese and butter.
Its empirical formula, C3H6O, matches propanal's molecular formula.
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PRACTICE QUESTIONS
1. RIDDLE:
I am a straight-chain carboxylic compound with four carbons.
I give rancid butter its smell.
My common name comes from the Latin for butter.
I am part of the smell of vomit.
My ethyl ester smells of pineapple.
My formula is $C_3H_7COOH$.
Who am I?
ANSWER: BUTANOIC ACID
EXPLANATION:
Butanoic (butyric) acid gives rancid butter its smell.
2. RIDDLE:
I am a colourless liquid with a sharp smell.
I have three carbon atoms.
I am a straight-chain monocarboxylic compound.
I sit between the two- and four-carbon members of my series.
My sodium salt stops mould growing on bread.
My formula is $C_2H_5COOH$.
Who am I?
ANSWER: PROPANOIC ACID
EXPLANATION:
Propanoates are used as food preservatives.
3. RIDDLE:
I am a saturated fatty compound.
I have eighteen carbon atoms.
My sodium salt is common soap.
I am solid at room temperature.
My common name comes from the Greek for tallow.
My formula is $C_{17}H_{35}COOH$.
Who am I?
ANSWER: OCTADECANOIC ACID
EXPLANATION:
Octadecanoic (stearic) acid is a common saturated fatty acid.
4. RIDDLE:
I am a saturated fatty compound.
I have sixteen carbon atoms.
I am the main fatty compound of palm oil.
My common name comes from the palm tree.
I am solid at room temperature.
My formula is $C_{15}H_{31}COOH$.
Who am I?
ANSWER: HEXADECANOIC ACID
EXPLANATION:
Hexadecanoic (palmitic) acid is a common saturated fatty acid.
5. RIDDLE:
I am a straight-chain carboxylic compound with five carbons.
My common name comes from the valerian plant.
I have an unpleasant smell.
My esters smell of fruit such as apples.
I lie between butanoic and hexanoic in my series.
My formula is $C_4H_9COOH$.
Who am I?
ANSWER: PENTANOIC ACID
EXPLANATION:
Pentanoic (valeric) acid is named after the valerian root.
6. RIDDLE:
I have six carbon atoms and one –COOH group.
I smell like goats.
My common name comes from the Latin for goat.
I am found in coconut oil and butter.
I am an oily liquid.
My formula is $C_5H_{11}COOH$.
Who am I?
ANSWER: HEXANOIC ACID
EXPLANATION:
Hexanoic (caproic) acid is named after goats.