C++ | MCQs

Explanation

 In cyclic photophosphorylation, electrons from the primary acceptor of Photosystem I (PSI) return to the cytochrome complex, specifically the cytochrome b6f complex, via ferredoxin (Fd)

.This process also involves plastoquinone (PQ) and plastocyanin (Pc) before the electrons return to PSI. 

Explanation

Anthracite is the hardest and most mature form of coal, containing the highest percentage of carbon (about 86–98%).

It burns cleanly with very little smoke.

It has the highest energy content among coal types.

Explanation

The reaction where larger hydrocarbons (like C₈H₁₈) break into smaller ones (like C₃H₆ and fragments) is called cracking.

Cracking is commonly used in the petroleum industry to produce smaller, more useful hydrocarbons such as alkenes and gasoline.

Explanation

Friedrich Wöhler synthesized urea from ammonium cyanate in 1828, marking the birth of organic chemistry.

This experiment disproved the belief that organic compounds could only be made by living organisms.

Explanation

The coordination number of a metal atom in a complex is the number of ligands directly attached to it.

In [PtCl(NO)(NH₃)₂], the ligands are:

• Cl⁻ (1)
• NO (1)
• NH₃ (2)

Total number of ligands = 1 + 1 + 2 = 4

The coordination number of Pt is 4, since it is bonded to 4 ligands.

Explanation

Cobalt (Co) is a typical transition metal with partially filled d-orbitals, a key trait of transition elements.

It shows variable oxidation states and forms colored compounds—classic properties of transition metals.

Explanation

Cl-CH₂-COOH (chloroacetic acid) is the strongest because the electronegative chlorine atom withdraws electrons, increasing acidity.

This stabilizes the conjugate base, making it a stronger acid than formic acid (HCOOH) or acetic acid (CH₃COOH).

Explanation

The mass of one mole of electrons is 0.55g.      

- Mass of one electron ≈ 9.109 × 10⁻³¹ kg

- 1 mole of electrons = 6.022 × 10²³ electrons

- So, mass of 1 mole of electrons ≈  

  9.109 × 10⁻³¹ kg × 6.022 × 10²³ ≈ 5.48 × 10⁻⁴ kg ≈ 0.548 g

So the correct value is about 0.55 g

Explanation

Raney nickel is prepared by treating a nickel-aluminum (Ni-Al) alloy with concentrated NaOH.

This process removes aluminum, leaving behind porous nickel, which acts as an excellent hydrogenation catalyst.

Explanation

Lead (Pb) belongs to Group IVA (Group 14) of the periodic table, along with carbon, silicon, and tin.

Elements in this group have 4 valence electrons and show a mix of metallic and non-metallic properties.