Why does the synthesis of a double sugar produce a formula of C12H22O11 instead of C12H24O12?

Question

I really need this question answered. Im completly stumped and cannot find the answer in my reading material provided by my teacher. thanks a bunch

Answer 1

you need a diagram, but i'll try to explain it simply. i just learned this yesterday. lets say you have a sucrose molecule. that's made of one glucose molecule and one fructose molecule, each with the formula C6H12O6

They combine when there is hydrolosis. so that means that two hydrogens and one oxygen from the glucose and fructose break away and form a water molecule. meanwhile, the two monosaccharides are connected by an oxygen. that means that there are now two H's subracted from the result as well as one O

so if all the elements were kept in, it would be C12H24O12, but since you subtract 2 H's and 1 O, it's C12H22O11

here, if you still don't understand
http://www.ualr.edu/botany/sucrose.gif

Answer 2

From that formula it looks like 2 H's and 1 O has been taken out so I'd say it was a dehydration reaction and a water molecule is removed while the reaction is taking place.

Answer 3

When two C6H12O6 molecules produce a double sugar, a water molecule is lost.
Basically 2 C-OH -> C-O-C + H2O

Answer 4

because it doesnt know how not to?

look to the differential synthesis, and methodology of production.

basically its a look for clues, and define the differences...

you know the effect, now identify the cause... theres your answer...