SCH4U UNIT 2 TEST | QUESTIONS AND ANSWERS | 2026 UPDATE | 100% CORRECT - OVS.
,
, SCH4U Unit 2 teSt | QUeStionS and anSwerS | 2026 Update | 100% CorreCt –
oVS Unit 2: organiC CHemiStry – ontario VirtUal SCHool
SECTION 1: HYDROCARBONS – ALKANES, ALKENES, ALKYNES (Questions 1-15)
**Question 1**
What is the general formula for alkanes?
A) CnH2n
B) CnH2n+2
C) CnH2n-2
D) CnH2n-6
**anSwer:** B) CnH2n+2
**rationale:** Alkanes are saturated hydrocarbons with only single bonds between carbon atoms.
Each carbon forms four single bonds, and the general formula is CnH2n+2. Examples: methane (CH4,
n=1), ethane (C2H6, n=2), propane (C3H8, n=3).
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**Question 2**
What is the IUPAC name for the compound CH3-CH2-CH2-CH2-CH3?
A) Pentane
, B) Butane
C) Hexane
D) Propane
**anSwer:** A) Pentane
**rationale:** This is a straight-chain alkane with 5 carbon atoms. The prefix "pent-" indicates 5
carbons, and the suffix "-ane" indicates an alkane (single bonds). The molecular formula is C5H12.
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**Question 3**
Which of the following is an isomer of butane (C4H10)?
A) But-1-ene
B) 2-Methylpropane
C) Cyclobutane
D) But-2-yne
**anSwer:** B) 2-Methylpropane
**rationale:** Isomers have the same molecular formula but different structural arrangements. 2-
Methylpropane (also called isobutane) has the formula C4H10, same as butane. But-1-ene has formula
C4H8; cyclobutane is C4H8; but-2-yne is C4H6.
---
**Question 4**
,
, SCH4U Unit 2 teSt | QUeStionS and anSwerS | 2026 Update | 100% CorreCt –
oVS Unit 2: organiC CHemiStry – ontario VirtUal SCHool
SECTION 1: HYDROCARBONS – ALKANES, ALKENES, ALKYNES (Questions 1-15)
**Question 1**
What is the general formula for alkanes?
A) CnH2n
B) CnH2n+2
C) CnH2n-2
D) CnH2n-6
**anSwer:** B) CnH2n+2
**rationale:** Alkanes are saturated hydrocarbons with only single bonds between carbon atoms.
Each carbon forms four single bonds, and the general formula is CnH2n+2. Examples: methane (CH4,
n=1), ethane (C2H6, n=2), propane (C3H8, n=3).
---
**Question 2**
What is the IUPAC name for the compound CH3-CH2-CH2-CH2-CH3?
A) Pentane
, B) Butane
C) Hexane
D) Propane
**anSwer:** A) Pentane
**rationale:** This is a straight-chain alkane with 5 carbon atoms. The prefix "pent-" indicates 5
carbons, and the suffix "-ane" indicates an alkane (single bonds). The molecular formula is C5H12.
---
**Question 3**
Which of the following is an isomer of butane (C4H10)?
A) But-1-ene
B) 2-Methylpropane
C) Cyclobutane
D) But-2-yne
**anSwer:** B) 2-Methylpropane
**rationale:** Isomers have the same molecular formula but different structural arrangements. 2-
Methylpropane (also called isobutane) has the formula C4H10, same as butane. But-1-ene has formula
C4H8; cyclobutane is C4H8; but-2-yne is C4H6.
---
**Question 4**
