The answer to this question would be: 2 mol
To answer this question, you need to know the molecular weight of Potassium. Molecular weight determines how much the weight of 1 mol of a molecule has.
Potassium or Kalium molecular weight is 39.1 gram/mol. Then, 78.20gram of potassium should be: 78.20g/ (39.1g/mol)= 2 mol
Dozen = 12,
ii. 1 score = 20
iii. 1 ream = 500
iv. 1 gross = 1.44
Answer: 35.4 grams
Explanation:
Molarity of a solution is defined as the number of moles of solute dissolved per Liter of the solution.
where,
Molality = 2.65
n= moles of solute =?
= volume of solution in ml = 445 ml
Putting in the values we get:
Mass of solute in g=
Thus 35.4 grams of 
is needed to prepare 445 ml of a 2.65 m solution of .
<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.
