Model Paper 1 — NEET STD 11 Science — Question

$1.$   Among the following, the correct statement is

$(A)$ Phosphates have no biological significance in humans

$(B)$ Between nitrates and phosphates, phosphates are less abundant in earth's crust

$(C)$ Between nitrates and phosphates, nitrates are less abundant in earth's crust

$(D)$ Oxidation of nitrates is possible in soil

$2.$   Among the following, the correct statement is

$(A)$ Between $\mathrm{NH}_3$ and $\mathrm{PH}_3, \mathrm{NH}_3$ is better electron donor because the lone pair of electrons occupies spherical ' $\mathrm{s}$ ' orbital and is less directional

$(B)$ Between $\mathrm{NH}_5$ and $\mathrm{PH}_5, \mathrm{PH}_5$ is better electron donor because the lone pair of electrons occupies $\mathrm{sp}^3$ orbital and is more directional

$(C)$ Between $\mathrm{NH}_3$ and $\mathrm{PH}_3, \mathrm{NH}_3$ is a better electron donor because the lone pair of electrons occupies $\mathrm{sp}^3$ orbital and is more directional

$(D)$ Between $\mathrm{NH}_3$ and $\mathrm{PH}_3, \mathrm{PH}_3$ is better electron donor because the lone pair of electrons occupies spherical ' $\mathrm{s}$ ' orbital and is less directional

$3.$  White phosphorus on reaction with $\mathrm{NaOH}$ gives $\mathrm{PH}_3$ as one of the products. This is a

$(A)$ dimerization reaction

$(B)$ disproportionation reaction

$(C)$ condensation reaction

$(D)$ precipitation reaction

Give the answer question $1,2$ and $3.$

$Na _{2} O , As _{2} O _{3}, N _{2} O , NO$ and $Cl _{2} O _{7}$

Number of amphoteric oxides is ..... .