userdata-paziras-Chem101-Chap_03A

Massx noofxinformulaxatomicmassofx x100

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: ar Mass of PbSO4 : 1 mole Pb = 1 mole S = 4 moles O = 1 x 207.2 g = 1 x 32.07 g = 4 x 16.00 g = 207.2 g 32.07 g 64.00 g 303.3 g 303.3 g PbSO4 3 ? g PbSO4 = 6.30 moles PbSO4 x ¾¾¾¾¾¾¾ = 1.91 x 10 g PbSO4 1 molePbSO4 4 Chemistry 101 5. Chapter 3 Calculate the number of moles in 2.45 g of magnesium sulfate. Formula of magnesium sulfate: 2+ 2­ MgSO4 MgSO4 1 mole MgSO4 ? moles MgSO4 = 2.45 g MgSO4 x ¾¾¾¾¾¾¾ ????? g MgSO4 1 mole MgSO4 = Molar Mass of MgSO4 : 1 mole Mg = 1 mole S = 4 moles O = 1 x 24.31 g = 1 x 32.07 g = 4 x 16.00 g = 24.31 g 32.07 g 64.00 g 120.38 g 1 mole MgSO4 ? moles MgSO4 = 2.45 g MgSO4 x ¾¾¾¾¾¾¾ = 0.0204 moles MgSO4 120.38 g MgSO4 5 Chemistry 101 Chapter 3 PERCENT COMPOSITION · The percent composit ion of a compound is the mass percent of each element in the co mpound. Mass % X = no. of X in formula x atomic mass of X x 100 molecular mass of compound The recommended daily allowance of table salt (sodium chloride) is 2000. mg NaCl. How many mg of Na are contained in 2,000. mg NaCl? First Step: Calculate the mass of 1 mo le of co mpound 1 mo le Na 1 mo le Cl = = 1 x 22.9 g 1 x 35.45 g 1 mo le o f NaCl = = 22.99 g 35.45 g = 58.44 g Second Step: Calculate the % by mass o f each element in the compound % Na = 22.99 g x 100 = 39.34% 58.44 g % Cl = 35.45 g x 100 = 60.66% 58.44 g Third Step: Check if the percentages add up to 100% 39.34 % Na + 60.6...
View Full Document

Ask a homework question - tutors are online