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### Topic: Molecular Mass of glucose  (Read 28478 times)

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#### general21

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• Mole Snacks: +0/-0 ##### Molecular Mass of glucose
« on: August 14, 2008, 07:46:55 AM »
The label on a popular sports drink states that it contains 0.500g of glucose in every 100mL of the drink. Glucose has the formula C6 H12 O6

i)   What is the molecular mass of glucose?
My workings:

Mr (C6 H12 O6) = 6 x Ar (C) + 12 x Ar (H) + 6 x Ar (O)
= 6 x 12 + 12 x 1 + 6 x 16
= 72 + 12 + 96
= 180 gmol^-1

ii)   What is the amount (mol) of glucose in 0.500g of glucose
My workings:

n = m/M
= 0.500/180
= 0.0027 mol

iii)   Calculate the number of molecules of glucose presenting 0.500g of glucose

iv)   Calculate the total number of atoms present in 0.500g of glucose

v)   What is the concentration of glucose in the sports drink? Express you answer in MolL^-1

#### tamim83 ##### Re: Molecular Mass of glucose
« Reply #1 on: August 14, 2008, 09:39:16 AM »
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iii)   Calculate the number of molecules of glucose presenting 0.500g of glucose

Use Avogadro's number as a conversion factor 1mol=6.022*1023 moleculues

Quote
iv)   Calculate the total number of atoms present in 0.500g of glucose

How many atoms are there total in one molecule of glucose?  Use this number to convert your previous answer from number of molecules to number of atoms

Quote
v)   What is the concentration of glucose in the sports drink? Express you answer in MolL^-1

You know moles from part ii, and the volume from the original question.   Note that molL-1=moles/Liters.  Make sure you convert mL-->L and you will be fine

Your previous two answers look great, hope this helps some 