Step-by-step approach for NEET problems:

For Gas Law Numericals (PV = nRT):

1. List given: P (atm?), V (L?), n (mol? or mass/M?), T (K? — convert if °C)
2. Identify what to find
3. Choose the right form: PV = nRT, or combined law $P_{1}V_{1}$/$T_{1}$ = $P_{2}V_{2}$/$T_{2}$
4. Substitute and calculate
5. Check units at the end

For Graham's Law:

1. Write r_{1}/r_{2} = √($M_{2}$/$M_{1}$) — heavier M always in numerator of the fraction under √
2. Substitute known values
3. Square both sides to eliminate √ when solving for M
4. Check: lighter gas should have HIGHER rate

For Molecular Speed Problems:

1. Use the formula directly with R = 8.314 J/(mol·K), M in kg/mol → v in m/s
2. For ratio problems (same gas, different T): v ∝ √T
3. For ratio problems (different gases, same T): v ∝ 1/√M

For Z and Real Gas Questions:

1. Z < 1 → attraction dominates → actual V < ideal V → gas more compressible
2. Z > 1 → repulsion/size dominates → actual V > ideal V → gas less compressible
3. $H_{2}$ and He ALWAYS Z > 1 (exception to remember)
4. All gases: Z → 1 as P → 0

For Dalton's Law:

1. n_total = Σn_i (sum all moles)
2. P_total = n_total RT/V
3. x_i = n_i/n_total
4. p_i = x_i × P_total

Time management in NEET:

• Straightforward gas law/Graham's law numericals: 30-45 seconds each
• Z factor interpretation (conceptual): 15-20 seconds
• Multi-step dalton's law: 60-90 seconds
• Assertion-Reason on gas laws: 30-45 seconds

Elimination approach for MCQs:

• Eliminate obviously wrong units (e.g., answer in kg when question asks for L)
• Eliminate answers that contradict fundamental principles (e.g., Z < 0 is impossible)
• Check order of magnitude: v_rms of $N_{2}$ at 300 K ≈ 517 m/s — unreasonable answers are > 10,000 m/s or < 10 m/s