<h3><u>Answer;</u></h3>
- Molecules along the surface of a liquid behave differently than those in the bulk liquid.
- Cohesive forces attract the molecules of the liquid to one another.
- Surface tension increases as the temperature of the liquid rises
<h3><u>Explanation;</u></h3>
- Surface tension is measured as the energy required to increase the surface area of a liquid by a unit of area. The surface tension of a liquid results from an imbalance of intermolecular attractive forces, the cohesive forces between molecules.
- A molecule in the bulk liquid experiences cohesive forces with other molecules in all directions, while a molecule at the surface of a liquid experiences only net inward cohesive forces.
- Surface tension decreases when temperature increases because cohesive forces decrease with an increase of molecular thermal activity.
Answer:
B
Explanation:
The tendency of a liquid to convert to vapour increases smoothly with increasing temperature. Vapour pressure shows the tendency of a liquid to convert to vapour. Increase In vapour pressure shows an increased tendency to convert to vapour. The higher the temperature, the higher the vapour pressure.
Answer:
A base that forms K⁺ and OH⁻ ions.
Explanation:
The KOH is an Arrhenius base.
A is <em>wrong</em>. A base does not form H⁺ ions.
B is <em>wrong</em>. A metal hydroxide forms K⁺ ions, not KO⁻ ions.
D is <em>wrong</em>. The metal forms K⁺ ions, KO⁻ ions.
<h3><u>Answer;</u></h3>
pH = 4.20
<h3><u>Explanation;</u></h3>
pKa = -log(6.30 × 10^-5)
pKa = 4.20
Moles of Benzoic acid = volume × molarity
= 0.050L × 1.00M
= 0.050moles benzoic acid
Moles of the salt = 0.050L × 1.00M
= 0.050 moles salt
Therefore;
0.050mols / 0.1 L = 0.50M
0.050mols / 0.1 L = 0.50M
Thus;
pH = 4.20 + log(0.50/0.50)
pH = 4.20
