Download presentation

Presentation is loading. Please wait.

1
Sample Calculations

2
Simplest Formula A g sample of caffeine ( reputed to be a stimulant for the central nervous system commonly used by students to avoid sleep ) contains g C, g H, g N, and g O. Calculate the simplest formula of caffeine.

3
Simplest Formula A g sample of caffeine ( reputed to be a stimulant for the central nervous system commonly used by students to avoid sleep ) contains g C, g H, g N, and g O. Calculate the simplest formula of caffeine. The concept of a formula implies that we can relate the numbers of atoms of each kind to each other and we must relate these masses to numbers of moles.

4
Simplest Formula A g sample of caffeine ( reputed to be a stimulant for the central nervous system commonly used by students to avoid sleep ) contains g C, g H, g N, and g O. Calculate the simplest formula of caffeine. 0.624 / = mol C 0.065 / = mol H 0.364 / = mol N 0.208 / = mol O

5
Simplest Formula A g sample of caffeine ( reputed to be a stimulant for the central nervous system commonly used by students to avoid sleep ) contains g C, g H, g N, and g O. Calculate the simplest formula of caffeine. divide by 0.624 / = mol C 0.065 / = mol H 0.364 / = mol N 0.208 / = mol O C4H5N2O

6
**Molecular Formula The simplest formula is C4H5N2O but the**

molar mass is found to be kg mol-1. What is the molecular formula?

7
**Molecular Formula The simplest formula is C4H5N2O but the**

molar mass is found to be kg mol-1. What is the molecular formula? The molar mass of the simplest unit is: 4 x x x = kg mol-1 Molecule must contain two C4H5N2O units and molecular formula is C8H10N4O2

8
Reaction Yield Ethanol, C2H5OH, is produced industrially by the following reaction: C2H4 + H2O > C2H5OH If the reaction proceeds with 100% yield, how much ethanol can be produced from 500 tonne of ethene ( C2H4 )?

9
Reaction Yield Ethanol, C2H5OH, is produced industrially by the following reaction: C2H4 + H2O > C2H5OH If the reaction proceeds with 100% yield, how much ethanol can be produced from 500 tonne of ethene ( C2H4 )? 500 tonne = 500 tonne x 1000 kg tonne -1 = 5.00 x 105 kg / kg mol -1 = 1.79 x 107mol ethene

10
Reaction Yield Ethanol, C2H5OH, is produced industrially by the following reaction: C2H4 + H2O > C2H5OH If the reaction proceeds with 100% yield, how much ethanol can be produced from 500 tonne of ethene ( C2H4 )? 500 tonne = 500 tonne x 1000 kg tonne -1 = 5.00 x 105 kg / kg mol -1 = 1.79 x 107mol ethene should get 1.79 x 107 mol of ethanol 1.79 x 107 mol x kg mol -1 = x 105 kg = 875 t

11
**Ethanol or Ethyl Alcohol**

Ethene or Ethylene H H C C H H Ethanol or Ethyl Alcohol H H H C C O H H H

12
**Gas Yield Oxygen gas can be produced on a small scale from the**

thermal decomposition of potassium chlorate, KClO3 to give oxygen and potassium chloride, KCl. Calculate the volume of oxygen at 298 K and 100 kPa that can be produced from kg of KClO3 .

13
**Gas Yield Oxygen gas can be produced on a small scale from the**

thermal decomposition of potassium chlorate, KClO3 to give oxygen and potassium chloride, KCl. Calculate the volume of oxygen at 298 K and 100 kPa that can be produced from kg of KClO3 . KClO > KCl O2

14
**Gas Yield Oxygen gas can be produced on a small scale from the**

thermal decomposition of potassium chlorate, KClO3 to give oxygen and potassium chloride, KCl. Calculate the volume of oxygen at 298 K and 100 kPa that can be produced from kg of KClO3 . KClO > KCl O2 2KClO > 2KCl O2

15
**Gas Yield Oxygen gas can be produced on a small scale from the**

thermal decomposition of potassium chlorate, KClO3 to give oxygen and potassium chloride, KCl. Calculate the volume of oxygen at 298 K and 100 kPa that can be produced from kg of KClO3 . 2KClO > 2KCl O2 This means 3 mol O2 / 2 mol KClO3 kg KClO3 / kg mol -1 = mol KClO3 0.436 mol KClO3 x 3 mol O2 / 2 mol KClO3 = mol O2

16
**Gas Yield Oxygen gas can be produced on a small scale from the**

thermal decomposition of potassium chlorate, KClO3 to give oxygen and potassium chloride, KCl. Calculate the volume of oxygen at 298 K and 100 kPa that can be produced from kg of KClO3 . n = mol O2 and V = nRT / P V = mol x 8.31 Nm mol-1 K-1 x 298 K 1.00x105 Nm2 = m3

17
Gas Mixtures What is the pressure at 300K in a 1.00L flask that contains 1.00 g of He and 1.00 g of H2?

18
**Gas Mixtures Ptotal = 1.86 x 106 Pa**

What is the pressure at 300K in a 1.00L flask that contains 1.00 g of He and 1.00 g of H2? nHe = 1.00 g / 4.00 g mol -1 = mol nH2 = / g mol -1 = mol n total = mol P = nRT / V = x 8.31 x 300 / 1.00 x 10 -3 Ptotal = 1.86 x 106 Pa

19
**Mole fraction Partial Pressure**

We can express the composition in mole fraction: He = n He / n total = 0.250mol / mol = NO UNITS!

20
**Mole fraction Partial Pressure**

The partial pressure is just : P He = He x Ptotal = x 1.86 MPa = MPa MPa = megapascal = 106 Pa

Similar presentations

Presentation is loading. Please wait....

OK

Percent by mass, mole fraction, molarity, and molality

Percent by mass, mole fraction, molarity, and molality

© 2017 SlidePlayer.com Inc.

All rights reserved.

Ads by Google

Ppt on grease lubrication pump Ppt on classical economics states Download ppt on oxidation and reduction potential Ppt on laser power transmission Ppt on earthquakes and volcanoes Ppt on needle stick injury policy Ppt on fast food industry in india Ppt on non biodegradable wastes Ppt on search engine project Imod display ppt online