edexcle igcse biology AGAIN!!!!

  • 0 votes

Hi guys , got another question if anyof u could help me out!

Students set up an apparatus. Flas A- A flask with water in it and a plant. There is a cotton wool at the to of the flask.

Flask B- A flask with water in it but NO PLANT! There is also a cotton wool at the top of the flask.

The mass of Flass a (with the plant) channged but the mass of flas b didnt. Explain why?

thankyouuu guysssssssssssss!

Posted Sun 4th November, 2012 @ 11:56 by SciTech

1 Answer

  • 1 vote

The plant in flask A is making products (oxygen) because it is respiring. This oxgen is caught in the flask because of the cotton wool. Oxygen has a mass therefore the mass will change in flask A, where as in flask B no product are being formed. Hope that helps x :)

Answered Wed 7th November, 2012 @ 21:53 by Katherine