Sucrose is made from joining glucose+fructose molecule in dehydration rxn...?

Question

sucrose is made from joining glucose+fructose molecule in dehydration rxn. wat is the molecular formula for this disaccharide?

a) C6H12O6

b) C12H24O12

c) C12H24O13

d) C12H22O11

e) C10H20O10

Answer 1

b

Answer 2

Fructose and glucose have the same formula (C6H12O6), so 12 + 12 - H2O gives ? Easy!

Answer 3

I can't believe some of these chemistry questions. I mean, honestly, are you even thinking?  Its absolutely disgusting that students aren't even willing to find a solution to a simple question.  Put down the cell phone, stop "texting" Cindy about hair-colors and THINK.  Solving a puzzle or answering a question for yourself is a rewarding experience. Try it, it doesn't taste bad or cause cancer.  I'm sorry if I'm being harsh here, but its simple, elementary arithmetic. You multiply the molecular formulas for glucose and fructose (which are the same) by two and subtract water (DEHYDRATION).  If you use your brain instead of thoughtlessly typing the entire question you would maybe pass the exam or, God forbid, learn something!

(C6H12O6)*2 = C12H24O12 - H2O = C12H22O11

Hint: Carbohydrates are repeating units of formaldehyde, CH2O, both fructose and glucose are hexose-sugars (contain 6 carbons).(CH2O)*6 = C6H12O6. Again, simple arithmetic. You should be able to do that without a calculator.

Answer 4

d) C12H22O11

If you add together glucose and fructose (same molecular formula, C6H12O6) you get C12H24O12. But in a dehydration reaction, water is lost in order to join the two monosaccharides. So you must subtract water (H2O, 2 hydrogens 1 oxygen) from the formula to get C12H22O11.  

Answer 5

D.

Answer 6

D