Explanation:
Chemical formula of chalcone is 
and during the preparation of chalcones, a base like sodium hydroxide acts like a catalyst. This catalyst helps in the abstraction of proton from the methyl group acetophenone in order to obtain a negative charge methylene group.
This methylene group then attacks carbonyl carbon of the benzaldehyde.
Answer:
[NO] = 1.72 x 10⁻³ M.
Explanation:
<em>2NO(g) ⇌ N₂(g)+O₂(g),</em>
Kc = [N₂][O₂] / [NO]².
- At initial time: [NO] = 0.171 M, [N₂] = [O₂] = 0.0 M.
- At equilibrium: [NO] = 0.171 M - 2x , [N₂] = [O₂] = x M.
∵ Kc = [N₂][O₂] / [NO]².
∴ 2400 = x² / (0.171 - 2x)² .
<u><em>Taking the aquare root for both sides:</em></u>
√(2400) = x / (0.171 - 2x)
48.99 = x / (0.171 - 2x)
48.99 (0.171 - 2x) = x
8.377 - 97.98 x = x
8.377 = 98.98 x.
∴ x = 8.464 x 10⁻².
<em>∴ [NO] = 0.171 - 2(8.464 x 10⁻²) = 1.72 x 10⁻³ M. </em>
<em>∴ [N₂] = [O₂] = x = 8.464 x 10⁻² M.</em>
Answer:
The strong acid reacts with the weak base in the buffer to form a weak acid, which produces few H+ ions in solution and therefore only a little change in pH.
Explanation:
When a strong acid is added to the buffer, the acid dissociates and furnish hydrogen ions which combine with the conjugate of the weak acid, forming weak acid. The weak acid dissociates to only some extent and can furnish only some protons and there is no significant change in the pH.
Hence, option B is correct.
Answer:
Tree sap flows over the leaf and preserves it.
Explanation:
Amber would preserve the image.
