Question

3. Mass of 0.3 mole of Water molecules is?
(a) 0.54gm (b) 60gm (c) 54gm(d) 5.4gm​

Answer 1

Answer : 5.4g.

Explanation : Mass of one mole of water molecule = 18g.

Therefore, mass of 0.3 mole of water molecule = 18 * 0.3 = 5.4g.

Here's how to calculate moles of water,

No. of moles of a substance = Given mass / Atomic mass.

Hope it helps you, please mark it as the brainliest.

Have a nice day !

Answer 2

Answer- The above question is from the chapter 'Some Basic Concepts of Chemistry'.

Concept used: Number of moles = $\frac{Given \: mass}{Molar \: mass}$

Given question: Mass of 0.3 mole of Water molecules is ____ .

(a) 0.54 gm

(b) 60 gm

(c) 54 gm

(d) 5.4 gm​

Answer: Number of moles of water molecules = 0.3 moles

Molar mass of water = 2[H] + 1[O] = 2(1) + 1(16) = 2 + 16 = 18 grams

We know that,

Number of moles = $\frac{Given \: mass}{Molar \: mass}$

⇒ Number of moles × Molar mass = Mass

Substituting the values above, we get,

Mass = 0.3 × 18

Mass = 5.4 grams

∴ Mass of 0.3 mole of Water molecules is (d) 5.4 gm​.