Pinaki Chowdhury

Started teaching in 1981 as an untrained teacher. Worked as technical supervisor in pulvarised coal based thermal power station. Worked as school administrator in India. Conducted action research in Chemistry Education.




Mpumalanga Department of education, South Africa

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Recent Reviews by Pinaki

Sun Mar 06, 2011 6:08 AM
5 Categorizing Chemical Reactions
Over all experience is excellent. When filling the gap using words alternate correct answers need to be accepted. Page 3 of 8: Vinegar and Baking Soda eaxmple does not respond correctly if it is written as acetic acid and bicarbonate. Again in page 3 of 8: Lemon juice is an organic acid, so there is supposed to be some un-dissociated acid molecules. Hence when water is added those un-dissociated acid molecules are supposed to get dissociated. This will increase the number of H+ ions in the solution. Hence addition of water increases the H+ ion concentration for an organic acid(lemon juice). Diluting further will change the situation.