Chemistry MDCAT MCQs

Organic, inorganic & physical chemistry MCQs

Practice Now
Test yourself with instant feedback
Showing 305 MCQs in Chemistry
Chemistry
A. Shifts to the left
B. Shifts to the right
C. No change
D. Catalyst is needed
Answer: The forward reaction reduces the number of gas moles (4 -> 2). By Le Chatelier\'s principle, increased pressure shifts equilibrium toward fewer moles (right).
Chemistry
A. Ice
B. Table salt
C. Diamond
D. Iron
Answer: Diamond is a network covalent solid where each carbon atom is tetrahedrally bonded to four other carbons through strong covalent bonds throughout the crystal.
Chemistry
A. Salt solution
B. Milk
C. Sugar solution
D. Air
Answer: Milk is a colloid where fat and protein particles are dispersed in water, exhibiting the Tyndall effect and other colloidal properties.
Chemistry
A. Ethanal
B. Ethene
C. Diethyl ether
D. Ethyl hydrogen sulfate
Answer: At 443 K (high temperature), ethanol undergoes dehydration to form ethene (CH2=CH2) and water via elimination of OH and H from adjacent carbons.
Chemistry
A. Iron catalyst
B. Platinum catalyst
C. Vanadium pentoxide (V2O5)
D. Nickel catalyst
Answer: V2O5 is the catalyst used in the contact process to oxidize SO2 to SO3, a key step in manufacturing H2SO4.
Chemistry
A. Linear
B. Trigonal planar
C. Trigonal pyramidal
D. Tetrahedral
Answer: NH3 has sp3 hybridization with 3 bonding pairs and 1 lone pair. The lone pair pushes the bonds down, giving trigonal pyramidal geometry.
Chemistry
A. +1
B. +2
C. -1
D. 0
Answer: An alpha particle consists of 2 protons and 2 neutrons (identical to a He2+ nucleus), giving it a charge of +2.
Chemistry
A. 3
B. 4
C. 5
D. 1
Answer: Fe3+ has configuration [Ar] 3d5. All five 3d orbitals have one unpaired electron each (Hund\'s rule), giving 5 unpaired electrons.
Chemistry
A. Na
B. Al
C. Ca
D. Fe
Answer: Al(OH)3 is amphoteric: it reacts with both acids (forming Al3+ salts) and bases (forming aluminate ions).
Chemistry
A. Oxygen
B. Chlorine
C. Hydrogen
D. CO2
Answer: Zn + 2HCl -> ZnCl2 + H2. Zinc reacts with dilute hydrochloric acid to produce zinc chloride and hydrogen gas.
Chemistry
A. 2
B. 3
C. 4
D. 5
Answer: C3H8O has three isomers: 1-propanol, 2-propanol (both alcohols), and methoxyethane (an ether).
Chemistry
A. CnH2n
B. CnH2n+2
C. CnH2n-2
D. CnHn
Answer: Alkanes are saturated hydrocarbons with only single bonds. Their general formula is CnH2n+2, reflecting the maximum number of hydrogen atoms.
Chemistry
A. -COOH
B. -CHO
C. -CO-
D. -OH
Answer: The aldehyde functional group is -CHO (formyl group), where a carbonyl carbon is bonded to at least one hydrogen atom.
Chemistry
A. sp3
B. sp2
C. sp
D. sp3d
Answer: NH4+ has 4 bonding pairs and 0 lone pairs on nitrogen, giving sp3 hybridization with tetrahedral geometry.
Chemistry
A. Na > Mg > Al > Si > P > S > Cl
B. Na < Mg < Al < Si < P < S < Cl
C. Cl > S > P > Si > Al > Mg > Na
D. Na = Mg = Al = Si = P = S = Cl
Answer: Atomic size decreases across a period from left to right due to increasing effective nuclear charge pulling electrons closer to the nucleus.
Chemistry
A. Pink
B. Colorless
C. Red
D. Blue
Answer: Phenolphthalein is colorless in acidic solutions (pH < 8.2) and turns pink in basic solutions (pH > 10).
Chemistry
A. 74 g/mol
B. 37 g/mol
C. 24.7 g/mol
D. 148 g/mol
Answer: Ca(OH)2 has n-factor = 2 (two OH- groups). Equivalent weight = 74 / 2 = 37 g/mol.
Chemistry
A. Ksp = [Ag+][Cl-]^2
B. Ksp = [Ag+][Cl-]
C. Ksp = [Ag+]^2[Cl-]
D. Ksp = [Ag+]/[Cl-]
Answer: For AgCl(s) <=> Ag+(aq) + Cl-(aq), the solubility product is Ksp = [Ag+][Cl-].
Chemistry
A. 2
B. 4
C. 6
D. 8
Answer: FCC has 8 corner atoms (8 x 1/8 = 1) + 6 face atoms (6 x 1/2 = 3) = 4 atoms per unit cell.
Chemistry
A. Acidic oxide
B. Basic oxide
C. Amphoteric oxide
D. Neutral oxide
Answer: SiO2 is an acidic oxide. It reacts with strong bases (like NaOH) to form silicates but does not react with acids (except HF).
8 9 10 11 12