Pakistan MCQs

Oxidation and reduction occur at separate electrodes in a galvanic cell.
Electron and ion movement complete the circuit.

Atomic orbitals and electron-pair repulsions determine bonding and molecular shape.
The stated option follows the relevant electronic or VSEPR rule.

The first law conserves energy: ΔU = q − w for work done by the system.
Substitution gives the stated internal-energy change.

Sertoli cells form the environment for spermatogenesis.
They also respond to follicle-stimulating hormone.

Oxidation numbers sum to the overall charge of the species.
Applying standard rules gives the stated value.

q = mcΔT = 2×4200×5.
The required heat is 42000 J.

Oxidation numbers sum to the overall charge of the species.
Applying standard rules gives the stated value.

q = mcΔT = 0.5×400×30.
The required heat is 6000 J.

Oxidation numbers sum to the overall charge of the species.
Applying standard rules gives the stated value.

q = mcΔT = 1.2×900×10.
The required heat is 10800 J.

Oxidation numbers sum to the overall charge of the species.
Applying standard rules gives the stated value.

q = mcΔT = 0.25×380×40.
The required heat is 3800 J.