ECAT Chemistry MCQs

Calibration creates a relationship between signal and concentration.
Unknown samples are interpreted using that relationship.

Primary standards have accurately known composition.
They are weighed directly to prepare or standardize solutions.

Hardness reduces soap lather and can form scale.
It may be temporary or permanent depending on associated anions.

BOD indicates biodegradable pollution in water.
High BOD can deplete dissolved oxygen in receiving waters.

Greenhouse gases reduce outgoing infrared energy loss.
Human emissions strengthen the natural greenhouse effect.

Polymers contain repeated structural units.
They may form by addition or condensation processes.

SO2 and nitrogen oxides form acids in the atmosphere.
Acid deposition can harm ecosystems and materials.

Addition polymerization opens double bonds without small-molecule byproducts.
Polyethene forms from ethene.

Carbohydrates include sugars, starch, glycogen, and cellulose.
Their biological roles include energy supply and structural support.

Condensation polymerization joins bifunctional monomers.
Water or another small molecule is often released.

Protein sequence determines folding and function.
Proteins act as enzymes, structures, receptors, and transporters.

The molecule has two carbons and an alcohol group.
The correct name is ethanol.