term1 Definition1term2 Definition2term3 Definition3
Please sign in to your Google account to access your documents:
Purpose
to find the molar mass of an unknown and become familiar with colligative properties
Method
Part a
-measure cyclohexane, pour in test tube and place in an ice/salt/water bath, gently stir until crystals form
-remove from bath and measure temp every 30 sec until we reach a temp between 12 to 15c.
-plot data on graph and use inflection point to determine the freezing point
Part b
-weight the unknown and add to cyclohexane
-place in ice/salt/water bath and gently stir with metal rod until slush appears
-remove from bath and record temp every 30 seconds until a temp between 10 to 15c is reached
-plot data on graph and determine the freezing point
-use this information to determine the molar mas of the unknown substance
what are solutions?
homogeneous mixtures that contain two or more substances
what are solvents?
the major component solution
what are solutes?
the minor component in a solution
what are colligative properties?
they are independent of the nature of the solute, depend only on the concentration
what are four colligative properties?
1.vapor pressure lowering
2. boiling point elevation
3. freezing point depression
4. osmotic pressure
what happens when vapor pressure = atmospheric pressure?
the solvent boils at this temperature and the gaseous and liquid states are in dynamic equilibrium
what have experiments found about the dissolution of non-volatile solutes in a solvent?
it lowers the vapor pressure of solvent, raises the boiling point, and lowers the freezing point
what does anti-freeze do concerning colligative properties?
lowers the freezing point and raises the boiling point of coolant (water)
Need help typing ? See our FAQ (opens in new window)
Please sign in to create this set. We'll bring you back here when you are done.
Discard Changes Sign in
Please sign in to add to folders.
Sign in
Don't have an account? Sign Up »
You have created 2 folders. Please upgrade to Cram Premium to create hundreds of folders!