All questions on Chemistry

how is polythene made?

Emma

Answers

Generally polythene, like most plastics is made from crude oil.

chloe

19 April 2011

check out this website http://www.packagingknowledge.com/plastic_bags.asp for a more in depth explanation

chloe

19 April 2011

When crude oil is heated in the distillation process it produces a gas called ethylene and polythene is made from this

chloe

19 April 2011

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Additional polymerisation - How does it work?

Emma

chemistry heeeeeeelp

(a) A pressure vessel contains a large volume of CO2 gas at 10 atm pressure. A membrane composed of a poly(ether ketone) polymer with thickness 100 microns and net effective area of 100 cm2 covers a small perforated port in the container. The solubility of CO2 at 10 atm is 6.97 x 10-4 moles/cm3 at 35 C. The diffusivity of CO2 in the polymer is known to be 2.29 x 10-8 cm2/s at this temperature.

How long will it take for 0.001 moles of CO2 to leak from the container at steady-state? Assume that the amount of carbon dioxide in the surroundings is insignificant. Express your answer in hours.

(b) If the diffusivity is observed to double when the temperature is increased by 10 degrees C, what is the activation energy for diffusion? Express your answer in units of eV

Emma

Cracking Hydrocarbons?

At school or revising at home I had no idea about cracking, what the process is or how it works, I nead help fully understanding. I am on higher tier for GCSE science. Thanks a lot.

Emma

what is an addition polymer?

Emma