BITSAT 2024 Shift 1 Paper

For the reaction 2SO2+O2⇌2SO3, we can determine the rate of appearance of SO3 from the given information.
Given:
Rate of disappearance of O2 is 2×10−4‌mol‌L−1‌ s−1.
The reaction rate expressions can be set up as:
‌ Rate of reaction ‌=−‌

1

2

‌

d[SO2]

dt

=−‌

d[O2]

dt

=‌

1

2

‌

d[SO3]

dt

To find the rate of appearance of SO3, we use the stoichiometry of the reaction. Since one mole of O2 produces two moles of SO3, the rate of appearance of SO3 is twice the rate of disappearance of O2.
‌

d[SO3]

dt

=2×(−‌

d[O2]

dt

)=2×(2×10−4)
Calculating this gives:
‌

d[SO3]

dt

=4×10−4‌mol‌L−1‌ s−1
Thus, the rate of appearance of SO3 is 4×10−4‌mol‌L−1‌ s−1.