MDCAT Chemistry MCQs

Alkanes are saturated because they contain the maximum number of hydrogens.
Their general acyclic formula is CnH2n+2.

Alkenes are unsaturated hydrocarbons.
Their double bond contains one sigma and one pi bond.

Both s and d electrons may participate in bonding or ion formation.
This permits several stable oxidation states.

Ligands act as Lewis bases.
They form coordinate covalent bonds with metal ions.

Coordination number counts metal-ligand attachment sites.
A bidentate ligand contributes two donor atoms.

Complex ions have coordinate bonds between metal and ligands.
Their charge includes metal and ligand charges.

Six CN- ligands contribute -6 total.
Fe must be +2 to give overall charge -4.

An ore contains a useful mineral in sufficient concentration.
Economic and technological factors determine whether extraction is worthwhile.

Roasting commonly converts sulfide ores to oxides.
Sulfur is often released as sulfur dioxide.

Calcination removes volatile components such as CO2 or water.
Carbonates may be converted to oxides.

The Haber process combines nitrogen and hydrogen.
It uses high pressure, elevated temperature, and an iron catalyst.

The Contact process oxidizes SO2 to SO3 using a catalyst.
SO3 is then converted into sulfuric acid through controlled absorption.