Question

Lactulose, C12 H22 O11, which is formed comercially from the isomerization of lactose, has a number of therapeutic uses. Calculate the following quantities:

A) Moles of H in 3.82 moles of C12 H22 O11

B)Grams of C12 H22 O11 in 3.82 moles of C12 H22 O11

C) Grams of C atoms in 3.82 moles of C12 H22 O12

D) Number of C atoms in 3.82 moles of C12 H22 O11 ans E) grams of O atoms in 2.5 kg of C12 H22 O11

Answer 1

molar mass of lactose = 342 g / mole

A) moles of H = 3.82 x 22

                          = 84.04

B) grams of C12 H22 O11 = moles x molar mass

                                           = 3.82 x 342

                                           = 1306 g

C) moles of C = 12 x 3.82 = 45.84

     grams of C = 45.84 x 12

                     = 550 g

D) number of C atoms = moles x avagadro number

                                      = 3.82 x 6.023 x 10^23

                                      = 2.30 x 10^24

E)    moles of C12 H22 O11 = 2500 / 342 = 7.31

   moles of O = 11 x 7.31   = 80.4

    mass of O = 80.4 x 16

               = 1286 g