Answer:
The correct option is: D. Two types of secondary (or intermolecular) bonding are present between hydrogen fluoride molecules, whereas only one type of secondary bonding is present between hydrogen chloride molecules
Explanation:
Boiling point of a chemical substance depends on the molecular mass and the intermolecular forces, which are the interactive forces present between chemical species
1. The <u>molecular mass of hydrogen fluoride (HF) is less than hydrogen chloride (HCl). </u>
2. But the <u>intermolecular forces present between the HF molecules are stronger </u>than the intermolecular forces present between the HCl molecules.
This is because hydrogen fluoride exhibits two types of intermolecular forces: strong hydrogen bonding and dipole-dipole interactions. Whereas, hydrogen chloride exhibits only one type of intermolecular force i.e. dipole-dipole interactions.
<u>Therefore, as a net result, the boiling point of HF is higher than the boiling point of HCl.</u>
The volume of CO₂ at STP = 2.8 L
<h3>Further explanation</h3>
Given
21 gram of sodium hydrogen carbonate-NaHCO₃
Required
Volume of CO₂
Solution
The decomposition of sodium bicarbonate into sodium carbonate, carbon dioxide, and water :
<em>
2 NaHCO₃(s) → Na₂CO₃(s) + CO₂(g) + H₂O(g)</em>
mol of NaHCO₃ :
= mass : MW NaHCO₃
= 21 g : 84 g/mol
= 0.25
From the equation, mol ratio of NaHCO₃(s) :CO₂(g) = 2 : 1, so mol CO₂ :
= 1/2 x mol NaHCO₃
= 1/2 x 0.25
= 0.125
At STP, 1 mol gas = 22.4 L, so for 0.125 mol :
= 0.125 x 22.4 L
= 2.8 L
<em>[H⁺] = 1,7×10⁻⁹ mol/dm³</em>
pH = -log[H⁺]
pH = -log[<span>1,7×10⁻⁹]
<u>pH = 8,77</u>
pH + pOH = 14
pOH = 14-8,77
<u>pOH = 5,23
</u>:)</span>
The answer is: <span>B) The phosphoric acid in cola easily removes dirt and grime.
</span>
Cola is a drink containing phosphoric acid in its complex composition. Acidic properties of Cola allow her to remove rust, dirt, and grime from chrome surface. In the same time, it is a very diluted solution of phosphoric acid which is very important not to damage a metal.
Lysosome: only ones that break down old cell parts<span>
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