Chemistry Test Inorganic Chemistry 3 — Questions and Answers
Question 1: Which element is the most electronegative?
- Oxygen
- Nitrogen
- Chlorine
- Fluorine (Correct answer)
Correct answer: Fluorine
Fluorine is the most electronegative element on the Pauling scale with a value of 3.98.
Question 2: Which of the following compounds exhibits the highest lattice energy?
- NaCl
- MgO (Correct answer)
- KBr
- CsI
Correct answer: MgO
MgO has the highest lattice energy due to the high charge (+2/-2) and small ionic radii of Mg2+ and O2-.
Question 3: Identify the conjugate base of H2PO4-:
- H3PO4
- PO43-
- HPO42- (Correct answer)
- H2PO4-
Correct answer: HPO42-
The conjugate base of H2PO4- is HPO42-, formed by losing one proton.
Question 4: Which d-block element has the electron configuration [Ar]3d5 4s1?
- Manganese
- Chromium (Correct answer)
- Iron
- Vanadium
Correct answer: Chromium
Chromium has configuration [Ar]3d5 4s1 due to the extra stability of a half-filled d subshell.
Question 5: What shape does the ClF3 molecule adopt?
- Trigonal planar
- T-shaped (Correct answer)
- Pyramidal
- Linear
Correct answer: T-shaped
ClF3 has 3 bonding pairs and 2 lone pairs, resulting in a T-shaped molecular geometry.
Question 6: Which of the following is a disproportionation reaction?
- 2H2 + O2 → 2H2O
- Cl2 + 2NaOH → NaCl + NaOCl + H2O (Correct answer)
- CaCO3 → CaO + CO2
- 2Na + Cl2 → 2NaCl
Correct answer: Cl2 + 2NaOH → NaCl + NaOCl + H2O
In Cl2 + 2NaOH → NaCl + NaOCl + H2O, chlorine is simultaneously oxidized and reduced (disproportionation).
Question 7: The hybridization of the central atom in PCl5 is:
- sp2
- sp3
- sp3d (Correct answer)
- sp3d2
Correct answer: sp3d
PCl5 has 5 bonding pairs and no lone pairs, requiring sp3d hybridization on phosphorus.
Chemistry Test Inorganic Chemistry 3
Which element is the most electronegative?