1 / 15

CHAPTER 3: CHEMICAL FORMULAE & EQUATIONS

CHAPTER 3: CHEMICAL FORMULAE & EQUATIONS. The Mole & Volume of Gas. 4S1 Thursday, 24/2/2011 7.30 – 8.40 am. Previously…. Relationship of Mass and Number of Moles Number of moles = Mass Molar mass Mass = Number of moles x Molar mass. × Molar mass (g mol -1 ).

samuru
Télécharger la présentation

CHAPTER 3: CHEMICAL FORMULAE & EQUATIONS

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. CHAPTER 3: CHEMICAL FORMULAE & EQUATIONS The Mole & Volume of Gas 4S1 Thursday, 24/2/2011 7.30 – 8.40 am

  2. Previously…

  3. Relationship of Mass and Number of Moles Number of moles = Mass Molar mass Mass = Number of moles x Molar mass × Molar mass (g mol-1) Mass (g) Number of moles (mol) ÷ Molar mass (g mol-1)

  4. Chemists determines the number of moles of any gas by measuring its volume as gases cannot be weighed • It was found that under the same temperature & pressure, equal volumes of all gases contain the same number of particles. Therefore, the concept of molar volume was introduced

  5. Molar volume = the volume occupied by one mole of gas Thus, the molar volume is also the volume occupied by 6.02×1023 particles of gas

  6. Molar volume of any gas is: • 22.4 dm3 mol-1 at STP • OR • 24 dm3 mol-1 at room conditions

  7. Refer Textbook page 37 Do correction for the unit of molar volume

  8. Relationship of Volume of Gas and Number of Moles Number of moles = Volume of gas Molar volume Volume of gas = Number of moles x Molar volume × Molar volume (dm3 mol-1) Volume of gas (dm3) Number of moles (mol) ÷ Molar volume (dm3 mol-1)

  9. REMINDER!!! SI unit of volume is dm3 & 1 dm3 = 1000 cm3

  10. Example 1 Find the number of moles of 6.72 dm3 of O2 at STP Number of moles of O2 gas = volume of O2 gas molar volume at STP = 6.72 dm3 22.4 dm3 mol-1 =0.3 mol

  11. Example 2 Find the number of moles of 560 cm3 of CO2 at room condition Number of moles of CO2 gas = volume of CO2 gas molar volume at room condition = 0.56 dm3* 24 dm3 mol-1 =0.0233 mol

  12. Example 3 Find the volume 1.5 mol of H2 gas at STP Volume of H2 gas = Number of moles of H2 gas × Molar volume at STP = 1.5 mol × 22.4 dm3 mol-1 = 33.6 dm3

  13. Example 4 Find the volume 0.4 mol of He gas at room conditions Volume of He gas = Number of moles of He gas × Molar volume at room condition = 0.4 mol × 24 dm3 mol-1 = 9.6 dm3

  14. Exercise 1 Find the number of moles of 896 cm3 of HCl gas at STP Number of moles of HCl gas = volume of HCl gas molar volume at STP = 0.896 dm3 22.4 dm3 mol-1 =0.04 mol

  15. Exercise 2 Find the volume 0.9 mol of N2 gas at room temperature Volume of N2 gas = Number of moles of N2 gas × Molar volume at RT = 0.9 mol × 24 dm3 mol-1 = 21.6 dm3

More Related