Question

परिकलनकीजिए। In a metallic piece of magnesium 8.46 1024 atoms of Mg are no. of moles of Mg present in it. प्रश्न-9 BF, ध्रुवीय अणु है, लेकिन द्विध्रुव आघूर्ण नहीं दर्शाता है। क्यों? BF, is a polar molecule, but it does not show dipole mom प्रश्न-10 वास्तविक विलयन और कोलॉइडी विलयन में कोई तीन अंतर लिखि Write any three differences between true solution an​

Answer 1

Given:

In a metallic piece of magnesium 8.46 × 10²⁴ atoms of Mg.

To find:

Moles of Mg present in metal?

Calculation:

$\rm \: moles = \dfrac{total \: atoms}{avagadro \: number}$

$\rm \implies \: moles = \dfrac{8.46 \times {10}^{24} }{6.023 \times {10}^{23} }$

$\rm \implies \: moles = 1.4 \times 10$

$\rm \implies \: moles = 14 \: mol$

So, 14 moles of Mg is present.

Why BF3 dipole moment is zero?

• Each B-F contains dipole moment.

• But, 3 (B-F) bonds are present at 120° to each other (sp² hybridised).

• Hence, net dipole moment cancels each other and becomes zero.

Hope It Helps.