✓ 1 MARKS
MCQ
🔥 APPEARED IN 3 BOARD SETS
Half-life ($t_{1/2}$) of a first order reaction is $1386 \text{ s}$. The value of rate constant is :
A
$0.5 \times 10^4 \text{ s}^{-1}$
B
$5.0 \times 10^{-4} \text{ s}^{-1}$
C
$0.5 \times 10^{-5} \text{ s}^{-1}$
D
$0.5 \times 10^{-2} \text{ s}^{-1}$
01 // VERIFIED BOARD OCCURRENCES
| Year | Paper Code | Set | Position |
|---|---|---|---|
| CBSE 2026 | Series 56-5 | Set 1 | Question 7 |
| CBSE 2026 | Series 56-5 | Set 2 | Question 8 |
| CBSE 2026 | Series 56-5 | Set 3 | Question 11 |
02 // OFFICIAL CBSE MARKING SCHEME BREAKDOWN
- Step 1: Stating the fundamental formula / law statement (+1 Mark)
- Step 2: Intermediate mathematical substitution or proof steps (+1 Mark)
- Step 3: Correct final value or conclusion with mandatory SI units (+1 Mark)