Pakistan MCQs

Actual yield is measured after the experiment.
It is usually lower than theoretical yield.

Solutions are homogeneous mixtures.
Any sampled portion has approximately the same composition.

Percent yield measures reaction and recovery efficiency.
Values below 100% commonly result from losses or incomplete reaction.

Heterogeneous mixtures contain distinguishable regions or phases.
Examples include sand in water and granite.

Molarity is a common concentration unit.
Its value changes with temperature because solution volume can change.

A physical change alters form or state without changing chemical identity.
Ice and liquid water are both H2O.

Molality is based on solvent mass.
It is largely independent of temperature.

Chloroplasts contain chlorophyll and photosynthetic membranes.
They convert light energy into chemical energy.

The cytoskeleton includes microtubules, microfilaments, and intermediate filaments.
It supports transport, division, and movement.

Channels and carriers help polar or charged substances cross membranes.
No direct energy input is required.

The central vacuole stores water, ions, pigments, and wastes.
Its pressure helps support plant tissues.

The cytoskeleton includes microtubules, microfilaments, and intermediate filaments.
It supports transport, division, and movement.