We know that domestic dogs are descended from wolves. Exactly when and how this occurred is still being studied; many experts indicate that dogs were first domesticated about 12,000 years ago, but a few DNA studies indicate a much earlier date for the split between the wolf and the dog, perhaps as long ago as 130,000 years.
Regardless of the exact timing of the divergence between wolves and dogs, one thing is true: both species display quite a bit of genetic diversity, particularly in size and coloration.In order to breed a dog of a specific size, all one has to do is choose parents with the appropriate variations. For instance, if you want to create a small dog breed, you would just breed the smallest dogs you have, then you would choose their smallest offspring to breed the next generation, and so on until you have reached the desired size.
A stock solution is a solution of a known concentration. Stock solution has a high concentration and therefore, the known amount of stock solution is used for preparing different concentrations, by diluting the same with the known amount of the solvent being used, such as water.
Convert the mass to moles .
85.1 g ÷ 20.18 g/mol = 4.21704658
convert the moles to molecules
4.2170 mol × 6.022^23 molecules/mol = 2.539^24
actual yield of ethanol = 305.0g
molar mass of sucrose = 342g
molar mass of ethanol =46g
mass of sucrose = 665g
mole of sucrose = mass / molar mass = 665/342
mole of sucrose =1.9 mole
sucrose : C2H5OH
1 : 4
1.9 : 1.9x4 =7.6 mole of C2H5OH are formed
mass (therotical yield ) of C2H5OH= mole x mass
mass (therotical yield ) of C2H5OH= 7.6 x 46 = 349.6g
percent yields of ethanol = actual /therotical x100
=305/349.6x100 = 87.24 %
