University:
Jackson College
Course:
CEM-141 | General Chemistry I
Academic year:

2024
Views:

170

Pages:

2
Author:

Reginald Stewart

Chem 11 More Mole Problems Name Titanium (IV) sulphate diboron tetrabromide manganese (II) phosphate Dinitrogen trioxide Name Formula Ti(SO4)2 Molar Mass 240.1 g/mol 341.2 g/mol 354.7 g/mol 76.0 g/mol B2Br4 Mn3(PO4)2 N2O3 1. How many moles are present in 2.45 x 1023 molecules of CH4? 2.45 x 1023 molecules x mol = 0.407 moles 23 6.02 x 10 molecules 2. How many molecules are there in 180 grams of H3PO3? 1.3 x 10 24 molecules 3. How many grams are there in 3.4 x 1024 molecules of Chlorine gas? 4.0 x 10 2 g 4. How many moles of O are present in 34 grams of Cu(OH)2? 0.70 moles O 5. How many grams of C are there in 2.3 x 1024 molecules of C3H8? 2.3 x 1024 molecules C3H8 x mol 6.02 x 10 molecules 23 x 3C x 1 C3H8 = 140 g C 6. How many atoms of Br are there in 5.7 g of CaBr2? 5.7 g CaBr2 x mol CaBr2 199.9 g x 2 Br x 1 CaBr2 = 3.4 x 1022 atoms Br 6.02 x 1023 molecules mol 12.0 g mol 7. How many moles of H2S occupy a volume of 7.25 L at RTP? 7.25 L x mol = 0.296 moles 24.5 L 8. What mass of sulphuric acid occupies a volume of 2.15 L at STP? 2.15 L x mol 22.4 L x 98.1 g = 9.42 g mol 9. How many oxygen atoms are present in 0.15 L of carbon dioxide gas at RTP? 0.15 L CO2 x mol 24.5 L x 2 C x 6.02 x 1023 atoms = 7.4 x 1021 atoms C 1 CO2 mol 10. What is the density of Hydrogen gas at RTP? 0.0824 g/L 11. What volume will 2.5 x 1025 molecules of chlorine gas occupy at STP? 930 L 12. What volume will 12.5 g of Methane gas (CH4) occupy at RTP? 19.1 L 13. The density of oxygen gas at STP is 1.43 g/L. How many molecules of oxygen gas do you have if you have 2.8g of oxygen gas? 2.8 g x L x 1.43 g mol x 6.02 x 1023 molecules = 5.3 x 1022 molecules 22.4L mol 14. A gas has a mass of 2.45 g and occupies a volume of 3.0 L of gas. What is the molar mass of this gas at RTP? 2.0 x 101 g/mol