Question

Please help me with a) i, a) ii, and b! thank you so much

Question 2 Solid Catalyst thene Tex Tube Glass Wool with Ethanol #Hansen Burner Ethene, C2H4(a) (molar mass 28.1 g/mol), may be prepared by the dehydration of ethanol, C2H5OH) (molar mass 46.1 g/mol), using a solid catalyst. A setup for the lab synthesis is shown in the diagram above. The equation for the dehydration reaction is given below. C,H,OH(8) ethanol Catalyst CH_(8) + H2O(g) AH998 - 45.5 kJ/mol ethene water AS398 = 126J/(K.mol)

Answer 1

Answer:

The reaction is:

C2H5OH (g) $\rightarrow$ C2H4 (g) +H2O (g). ......…....... (1)

Ethanol. Ethene. Water

Given that mass of ethanol taken = 0.2g

Or Moles of ethanol taken in test tube = mass/Molar mass

= 0.2/46.1 (molar mass of Ethanol is 46.1 gram per mole)

= 0.004339 moles of ethanol

A. Now we need to determine the actual number of moles of ethene produced in the experiment

Given that , volume of gas collected = V =0.0854 lit

T= 305 Kelvin Total pressure P is 0.822 atm

Using this data we need to find amount of ethene produced. This can be done by using ideal gas equation.

But for that we need to find vapour pressure of ethene which is given as :

Total Pressure P = VP ethene + VP water.........(2)

Vapour pressure of water is given as 35.7 torr at 305 K.

Convert this to atm ( 1 atm = 760 torr)

Or VP water = 35.7/760

= 0.0469 atm

Put in equation (2)

0.822 = VP ethene + 0.0469

Or VP ethene = 0.7751 atm

Apply ideal gas equation to find number of moles of ethene

PV = nRT

Take R gas constant as 0.08206 L atm/mol•K

0.7751atm * 0.0854 L = n * 0.08206 L atm /mol K * 305 K

0.06619 = n * 25.0283

Or n = 0.002644 moles of ethene produced.

Thus actual number of moles of ethene produced is 0.002644 moles.

ii.that would be produced if the dehydration went to completion

So as per the stoichiometry of the chemical equation.

Theoretically, one mole of Ethanol on complete dehydration gives one mole of ethene as clear from equation 1

But we have taken 0.004339 moles of ethanol in the test tube so, same number of moles of ethene has to be produced if the dehydration went to 100% completion

Thus theoretical yield of ethene : 0.004339 moles

B. Calculating the percentage yield of ethene

percentage yield is given as

= (Actual amount produced/Theoretical yield)* 100

= (0.002644 moles / 0.004339 moles ) * 100

= 60.94 %

Thus the percentage yield of ethene is 60.94 %