Answer:
2.03
Explanation:
Let's <u>assume we have 1 L of the solution</u>:
- There would be 2.07 ethylene glycol moles.
- The solution would weigh (1000 mL * 1.02 g/mL) = 1020 g.
With that information we can <u>calculate the molality</u>:
- molality = moles of solute / kg of solvent
- molality = 2.07 moles / (1020 ÷ 1000) = 2.03 m
Keep in mind that this is only an estimate, as we used the kg of the solution and not of the solvent.
Answer:
1.95*10²² molecules are in 5.50 grams of AgNO₃
Explanation:
Being the molar mass of the elements:
- Ag: 107.87 g/mole
- N: 14 g/mole
- O: 16 g/mole
then the molar mass of the compound is:
AgNO₃: 107.87 g/mole + 14 g/mole + 3*16 g/mole= 169.87 g/mole
Then you can apply the following rule of three: if 169.87 grams of the compound are present in 1 mole, 5.50 grams will be present in how many moles?

moles= 0.0324
Avogadro's Number or Avogadro's Constant is called the number of particles that make up a substance (usually atoms or molecules) and that can be found in the amount of one mole of said substance. Its value is 6.023*10²³ particles per mole. Avogadro's number applies to any substance.
You can apply the following rule of three: if by definition of Avogadro's Number 1 mole of the substance contains 6.023 * 10²³ molecules, 0.0324 moles how many molecules will it have?

molecules=1.95*10²²
<u><em>1.95*10²² molecules are in 5.50 grams of AgNO₃</em></u>
Molarity = moles of solute / liters of solution
M = 0.5 / 0.05
M = 10.0 mol/L⁻¹
hope this helps!
2nd family
calcium is in the second family