Periodic Trends
Organic Chemistry
Reactions & Energy
Reactions & Energy
Reactions & Energy
100
Which element is liquid at room temperature?
A) Gallium
B) Mercury
C) Sodium
D) Bromine
Mercury
100
Which molecular formula represents an alkane?
A) C₂H₄
B) C₃H₆
C) C₄H₁₀
D) C₅H₈
C₄H₁₀
100
Combustion reactions are always:
A) Endothermic
B) Neutral
C) Exothermic
D) Reversible
Exothermic
100
Which has the greater mass: 1 mol of O₂ or 1 mol of CO₂?
A) O₂
B) CO₂
C) Same mass
D) Cannot tell
CO₂
100
What is NaHCO₃ commonly called?
A) Baking soda
B) Washing soda
C) Table salt
D) Chalk
Baking soda
200
Which element has the symbol W?
A) Tungsten
B) Tin
C) Silver
D) Zinc
Tungsten
200
Which functional group defines alcohols?
A) –OH
B) –COOH
C) –NH₂
D) –CHO
–OH
200
Which reaction type has one reactant?
A) Synthesis
B) Decomposition
C) Neutralization
D) Single displacement
Decomposition
200
Which particle is smallest in size?
A) Na
B) Na⁺
C) Na⁻
D) Na²⁺
Na⁺
200
Why does ice float on water?
A) Lower density
B) Higher mass
C) Stronger bonds
D) More hydrogen
Lower density
300
Which element breaks the first ionization energy trend?
A) Be
B) B
C) C
D) N
B
300
Which compound is unsaturated?
A) Alkane
B) Alkene
C) Cycloalkane
D) Alkyne
An alkene
300
What gas is produced when acids react with metals?
A) Oxygen
B) Hydrogen
C) Carbon dioxide
D) Nitrogen
Hydrogen
300
Which has the most particles?
A) 22.4 L O₂ at STP
B) 1 mol O₂
C) 32 g O₂
D) All equal
All are equal
300
Why do ionic compounds conduct electricity when molten?
A) Mobile ions
B) Free electrons
C) Dissolved molecules
D) Weak bonds
Mobile ions
400
Which element is the most electronegative?
A) Oxygen
B) Nitrogen
C) Chlorine
D) Fluorine
Fluorine
400
Which reaction converts an alcohol into an alkene?
A) Substitution
B) Elimination
C) Addition
D) Condensation
Elimination
400
What does a catalyst change in a reaction?
A) Activation energy
B) ΔH
C) ΔG
D) Equilibrium constant
Activation energy
400
Why is CO₂ nonpolar?
A) Linear symmetry
B) Weak bonds
C) No lone pairs
D) Low electronegativity
Linear symmetry
400
Why does salt lower the freezing point of ice?
A) Freezing point depression
B) Increased density
C) Heat absorption
D) Ionic bonding
Freezing point depression
500
Which species has the highest ionization energy?
A) Na
B) Na⁺
C) Mg
D) Mg⁺
Na⁺
500
Which type of carbon is required for a molecule to be optically active?
A) Carbon in a double bond
B) Terminal carbon (–CH₃)
C) Asymmetric (chiral) carbon
D) Carbon in a ring
Asymmetric (chiral) carbon
500
On an energy diagram, what does the peak represent?A) Reactants
B) Products
C) Transition state
D) Catalyst
Hint:Look at position B
Transition state / Activated complex
500
Which noble gas has the highest boiling point?
A) Ne
B) Ar
C) Kr
D) Xe
Xenon
500
Why does perfume spread faster in warm air?
A) Convection only
B) Faster diffusion
C) Effusion
D) Lower density
Faster diffusion