# Question #d45c9

##### 1 Answer

#### Explanation:

Your strategy here will be to

use glucose'smolar massto determine how manymolesyou have in that sampleuseAvogadro's numberto determine how manymoleculesyou have in that many molesuse glucose's chemical formula to find how manyatomsyou get in that many molecules

So, glucose, **one mole** of glucose has a mass of

Use the molar mass of glucose as a *conversion factor* to determine how many moles you have in your

#843.211color(red)(cancel(color(black)("g"))) * overbrace(("1 mole C"_6"H"_12"O"_6)/(180.156color(red)(cancel(color(black)("g")))))^(color(blue)("molar mass of glucose")) = "4.68045 moles C"_6"H"_12"O"_6#

Now, **Avogadro's number** tells you how many atoms or molecules you get in **one mole** of a given substance. Since you know how many moles of glucose you have in your sample, you can use Avogadro's number as a *conversion factor* to help you go from moles to number of **molecules**

#4.68045color(red)(cancel(color(black)("moles"))) * overbrace((6.022 * 10^(23)"molec.")/(1color(red)(cancel(color(black)("mole")))))^(color(purple)("Avogadro's number")) = 2.81857 * 10^(24)"molec."#

To get the number of atoms you get in that many molecules of glucose, focus on figuring out how many atoms you get in **one molecule** first.

Each molecule of glucose is made up of

,six atomsof carbon#6 xx "C"# ,twelve atomsof hydrogen#12 xx "H"# ,six atomsof oxygen#6 xx "O"#

This means that **one molecule** of glucose will contain a total of

#6 + 12 + 6 = "24 atoms"#

The number of atoms present in your sample will thus be equal to

#2.81857 * 10^(24)color(red)(cancel(color(black)("molec."))) * "24 atoms"/(1color(red)(cancel(color(black)("molec.")))) = color(green)(|bar(ul(color(white)(a/a)6.76457 * 10^(25)"atoms"color(white)(a/a)|)))#

The answer is rounded to six **sig figs**, the number of sig figs you have for the mass of sucrose.