Answer:
moles = no. of molecules / Avogadro's number
= 2.26 x 10^33 / 6.022 x 10^23
= 3752906011
Round to significant figures which is 3 = 3.75 x 10^9 mol
Explanation: The formula for finding how many moles of a substance when given the amount of molecules is: moles = number of molecules / Avogadro's number
<u>We are given:</u>
Mass of Na added = 4.35 grams
Mass of water = 105 grams
<u>Mass Percent of Na:</u>
Total mass of the solution = mass of solute + mass of solvent
Total mass of the solution = 4.35 + 105 = 109.35 grams
Mass percent of solute = (mass of solute / mass of solution) * 100
Mass percent of Solute = (4.35 / 109.35) * 100
Mass percent = 3.978 %