Question

Among the following, the correct statements are
I. Lithium forms solid hydrogen carbonate
II. LiCl is soluble in ethanol
III. The formula of lithium oxide is LiO
IV. Lithium hydroxide decomposes on heating

• A. II, IV only
• B. I, III only
• C. II, III only
• D.

Hint:

LiCl is soluble in ethanol due to its covalent character; LiOH decomposes on heating to Li\(_2\)O + H\(_2\)O.

Answer 1

The Correct Option is A

Let’s verify each statement:
- I. False – Lithium hydrogen carbonate (LiHCO\(_3\)) is unstable and does not exist as a solid.
- II. True – LiCl is covalent enough to dissolve in ethanol.
- III. False – Lithium oxide has the formula Li\(_2\)O, not LiO.
- IV. True – Lithium hydroxide decomposes on heating to give lithium oxide and water.

Answer 2

Among the following, the correct statements are:

I. Lithium forms solid hydrogen carbonate
II. LiCl is soluble in ethanol
III. The formula of lithium oxide is LiO
IV. Lithium hydroxide decomposes on heating

Step 1: Analyze Statement I – "Lithium forms solid hydrogen carbonate":
This is incorrect. Unlike other alkali metals, lithium does not form a stable solid hydrogen carbonate (LiHCO₃). It exists only in solution and cannot be isolated as a solid due to lithium's small size and high charge density.
→ Statement I is incorrect.

Step 2: Analyze Statement II – "LiCl is soluble in ethanol":
LiCl has significant covalent character due to the small size of the lithium ion. As a result, it dissolves not only in water but also in organic solvents like ethanol.
→ Statement II is correct.

Step 3: Analyze Statement III – "The formula of lithium oxide is LiO":
This is incorrect. The correct formula for lithium oxide is Li₂O, since lithium has a +1 oxidation state and oxygen is –2. To balance the charges, two lithium ions are needed per oxide ion.
→ Statement III is incorrect.

Step 4: Analyze Statement IV – "Lithium hydroxide decomposes on heating":
Lithium hydroxide (LiOH) behaves differently from other group 1 hydroxides. On strong heating, it decomposes to form lithium oxide and water:
LiOH → Li₂O + H₂O
→ Statement IV is correct.

Final Answer:
\[ \boxed{\text{II, IV only}} \]