Question

Module Three Assignment Name: Chemical Composition and Calculations Instructions: Write out a linear equation to answer each question 1. How many molecules of oxygen are found in 3.00 moles of oxygen? 2. How many grams are in 5.87x10 molecules of sulfur? 3. How many atoms are found in 4.20 g of magnesium (Me)? 4. How many atoms are found in 3.45 g of CO ? Instructions: Calculate the mass percent composition of a compound. Show all of your work. 5. Calculate the mass percent of 0.485 g of H, which reacts with oxygen to form 2.32 g HO. 6. Calculate the mass percent of manganese (Mn) in potassium permanganate (KMnO,

Answer 1

1. Imole = 6.022x183 particles. 23 molecules 3 moles of oxygen = 3x6:022x10 notes of oxygen = 1.8066x10 molecules of snygen 24 2. First we will calculate the moles. no a particle na S. 87410 - 6.022x1023 23 9 NA4 Avogadro's umber h = W e given mass no cf moles memoar mass how we have moles & molar mass of s= 32, we can eaisly calculate the mass (W) Nanom = S:87x10"_x32 - 6.022x183 - 12 N = 27.34 x 10 g 3. 0.175 moles first let's calculate moles n=W = 4.20 = 24 now I moles = 6.082x10 atoms 0.175 moles = 0.175X6.022 X 1023 = 1,05 xjos atoms.