نامیاتی کیمیا

Written by Dr. Ayesha Nadeem (Chemistry)

نیٹ · کیمیا · 7 سوالات

نام: ____________________ تاریخ: ____________

What is the IUPAC name of (CH3)2CHCH3?
- A 2-methylbutane
- B 2-methylpropane
- C Butane
- D Propane
Optical isomerism requires the presence of:
- A A double bond
- B A hydroxyl group
- C A chiral carbon atom
- D A benzene ring
Which compound can undergo the aldol condensation?
- A Methanal
- B 2,2-dimethylpropanal
- C Benzaldehyde
- D Ethanal
Benzene reacts with bromine in the presence of FeBr3 to give:
- A Phenol
- B Cyclohexane
- C Bromobenzene
- D Hexabromocyclohexane
How many sigma bonds are there in a benzene molecule?
- A 9
- B 15
- C 12
- D 6
What is the functional group of an ester?
- A -COOH
- B -CHO
- C -COO-
- D -O-
Which reagent converts a primary alcohol into a carboxylic acid on heating under reflux?
- A Sodium chloride
- B Acidified potassium dichromate
- C Concentrated sulphuric acid only
- D Dilute hydrochloric acid

جوابی کلید

1. B, 2. C, 3. D, 4. C, 5. C, 6. C, 7. B

The longest chain has three carbons (propane) with a methyl group on carbon 2.
A carbon bonded to four different groups gives two mirror-image forms that rotate plane-polarised light in opposite directions.
Aldol condensation needs a hydrogen on the carbon next to the carbonyl group. Ethanal has one, and the others do not.
This is electrophilic substitution. One hydrogen on the ring is replaced by bromine, and HBr is formed.
There are six C-C sigma bonds and six C-H sigma bonds, so twelve in total.
An ester has the group -COO-, as in ethyl ethanoate, CH3COOC2H5.
Acidified potassium dichromate is a strong oxidising agent that oxidises the alcohol, through the aldehyde, to the acid.