IIT-JEE 2008 · Paper 1 · Chemistry Q64

← IIT-JEE 2008 · Paper 1

ChemistrySingle correct+4 / -1Question 64 of 69

Passage

Paragraph for Question Nos. 64 to 66

There are some deposits of nitrates and phosphates in earth's crust. Nitrates are more soluble in water. Nitrates are difficult to reduce under the laboratory conditions but microbes do it easily. Ammonia forms large number of complexes with transition metal ions. Hybridization easily explains the ease of sigma donation capability of $\ce{NH3}$ and $\ce{PH3}$ . Phosphine is a flammable gas and is prepared from white phosphorous.

Among the following, the correct statement is

Phosphates have no biological significance in humans

Between nitrates and phosphates, phosphates are less abundant in earth's crust

Between nitrates and phosphates, nitrates are less abundant in earth's crust

Oxidation of nitrates is possible in soil

Answer and worked solution

Official answer: C

From the passage. Nitrates are very soluble, so they are leached away by water, and microbes reduce them readily; phosphates are insoluble and stay as large rock deposits. So nitrates are less abundant in the crust.

(A) is false (bones, ATP, DNA), (B) is the reverse, and (D) is wrong because nitrate already has N in its highest state (+5) and can only be reduced.

(C)

Topics:Group 15

← Previous question Next question →

IIT-JEE 2008 · Paper 1, Chemistry question 64