Q20 / 75 · JEE Main 2026 (21 January Shift 1) · Chemistry
Given below are two statements :
Statement I : The number of pairs among $\left[\mathrm{SiO}_{2}, \mathrm{CO}_{2}\right],\left[\mathrm{SnO}, \mathrm{SnO}_{2}\right],\left[\mathrm{PbO}, \mathrm{PbO}_{2}\right]$ and $\left[\mathrm{GeO}, \mathrm{GeO}_{2}\right]$, which contain oxides that are both amphoteric is 2.
Statement II: $\mathrm{BF}_{3}$ is an electron deficient molecule, can act as a Lewis acid, forms adduct with $\mathrm{NH}_{3}$ and has a trigonal planar geometry.
In the light of the above statements, choose the correct answer from the options given below :
Statement I : The number of pairs among $\left[\mathrm{SiO}_{2}, \mathrm{CO}_{2}\right],\left[\mathrm{SnO}, \mathrm{SnO}_{2}\right],\left[\mathrm{PbO}, \mathrm{PbO}_{2}\right]$ and $\left[\mathrm{GeO}, \mathrm{GeO}_{2}\right]$, which contain oxides that are both amphoteric is 2.
Statement II: $\mathrm{BF}_{3}$ is an electron deficient molecule, can act as a Lewis acid, forms adduct with $\mathrm{NH}_{3}$ and has a trigonal planar geometry.
In the light of the above statements, choose the correct answer from the options given below :
- AStatement I is true but Statement II is false
- Correct answerBBoth Statement I and Statement II are true
- CBoth Statement I and Statement II are false
- DStatement I is false but Statement II is true
Solution
Statement I: Checking amphoteric nature of oxide pairs:
$[SiO_2, CO_2]$: Both acidic (non-metal oxides)
$[SnO, SnO_2]$: Both amphoteric
$[PbO, PbO_2]$: $PbO$ is amphoteric but $PbO_2$ is predominantly acidic/oxidizing
$[GeO, GeO_2]$: Both amphoteric (Ge is metalloid)
2 pairs have both oxides amphoteric. Statement I is true.
Statement II: $BF_3$ has B with 6 valence electrons (electron deficient), acts as Lewis acid, forms $BF_3 \cdot NH_3$ adduct, has $sp^2$ hybridization giving trigonal planar geometry. Statement II is true.
$[SiO_2, CO_2]$: Both acidic (non-metal oxides)
$[SnO, SnO_2]$: Both amphoteric
$[PbO, PbO_2]$: $PbO$ is amphoteric but $PbO_2$ is predominantly acidic/oxidizing
$[GeO, GeO_2]$: Both amphoteric (Ge is metalloid)
2 pairs have both oxides amphoteric. Statement I is true.
Statement II: $BF_3$ has B with 6 valence electrons (electron deficient), acts as Lewis acid, forms $BF_3 \cdot NH_3$ adduct, has $sp^2$ hybridization giving trigonal planar geometry. Statement II is true.
Hence, the correct answer is option: 'B'.