Question

Question about dehydration reactions. What is the molecular formula made by linking ten glucose molecules together by dehydration actions? The answer key gives the answer as C60H120O60.
Can someone explain this? I was under the assumption that some molecules were added during dehydration but according to the answer this doesn't seem to be the case.

Answer 1

Well if it's a dehydration reaction what does that mean? A water molecule is removed. Therefore 1 O and 2 H are removed from the formula: C6 H10 O5. Now you must multiply everything by 10, so:

6 x 10 = 60
10 x 10 = 100
5 x 10 = 50

= C60 H100 O50

However, one OH molecule and one H molecule are combined in the reaction, therefore an extra H2O is not removed at the end of both sides of the chain. Therefore you must add 2H and 1O to the formula above, therefore the final answer is:

C60 H102 O51

Answer 2

Thanks!