Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
O Chem 2
Unit 3&4
| Question | Answer |
|---|---|
| What does the separation of two or more liquid compounds by distillation depend? | Boiling point differences |
| What is mean by the term vapor pressure | THe pressure exerted by a liquid on it's environment |
| How is boilint point of a pure liquid defined? | THemp. where the liquid vapor pressure equals the pressure exerted by the atmosphere. |
| In a collection of compounds of similar molecular weight which will have the higher boiling points and which will have the lower bpt? | polar compounds have higher, non-polar compounds are lower. |
| Upon what does the boiling point of a mixture depend? | Wpon the vapor pressures of the various components |
| What affects can impurities have on the observed boiling point? | the observed boiling point will be either higher or lower (determined only by experimentation) |
| What distinguished simple distillation from fractional distillation? | 1. The # of vaporizations- condensation cycles. 2.Simple distillations typically have 1 to 2 vaporization- condensation cycles. 3. Fractional distillations have 3 or more vaporization- condensation cycles. |
| What is meant by the term distiallate? | Distillate refers to the condensed liquid. |
| During distillation how does the composition of the liquid remaining in the distilling flask change? | The liquid remaining in the distilling flask becomes richer in the less volatile component. |
| During distillation how does the boiling point of the liquid remaining in the distilling flask change? | The boiling point of the liquid remaining in the distilling flask rises during the course of the distillation. |
| Under what circumstances is simple distillation commonly employed? | 1.to purify an organic compound and determine its boiling point. 2. to seperate a high boiling organic compound from a low boiling organic solvent. |
| The what level should one fill the distilling flask prior to starting a simple distillation? | The distilling flask should be no more than 1/3 to 1/2 full. |
| How does one know whether or not the hermometer is positioned correctly in the distilling head of a distillation apparatus? | The top of the thermometer bulb should be level w/ bottom of the side arm. |
| How should the distilling flask/three-way adapter assembly be positioned? | The distilling flask/ three-way adapter should be vertical. |
| How is heat input to the distilling flask from the heating mantle controlled? | Via a variable transformer. |
| When should a distillation be stopped? | Before the distilling flask reaches dryness. |
| Upon what does the efficiency of a fractionating column depend? | The effect of a fractionating column depends upon the number of vaporization-condensation cycles. |
| What rate of distillate collection indicates a slow, steady distiallation? | A slow, steady distillation is characterized by a distillation rate of 1 drop every 2-3 sec. |
| How does the use of excessvie heat affect fractional distillation? | The number of possible vaporization-condensation cycles decreases and speration is compromised. |
| How does the use of too little heat affect fraction distillation | The fractionating column loses more heat than the ascending. |
| What advantage are associate with the use of steam distillation? | Complex vacuum steps are not required. |
| What industries make use of steam distiallation? | Perfume industry flavor industry |
| Upon what does steam distillation depend? | The immiscibility of organic compounds w/water (Can't mix) |
Created by:
jackscam
Popular Chemistry sets