CHEMISTS USE RELATIVE MASSES TO COUNT ATOMS AND MOLECULES

In any chemical reaction, a specific number of reactant atoms or molecules react to form a specific number of product atoms or molecules. For example, when carbon and oxygen combine to form carbon dioxide, they always combine in the ratio of one carbon atom to one oxygen molecule. A chemist who wants to carry out this reaction in the laboratory would be wasting chemicals and money if she were to combine, say, four carbon atoms for every one oxygen molecule. The excess carbon atoms would have no oxygen molecules to react with and would remain unchanged. 

How is it possible to measure out a specific number of atoms or molecules Rather than counting these particles individually, chemists can use a scale that measures the mass of bulk quantities. Because different atoms and molecules have different masses, however, a chemist can t simply measure out equal masses of each. Say, for example, he needs the same number of carbon atoms as oxygen molecules. Measuring equal masses of the two materials would not provide equal numbers. 

The number of balls in a given mass of Ping-Pong balls is very different from the number of balls in the same mass of golf balls. 

CHEMISTS USE RELATIVE MASSES TO COUNT ATOMS AND MOLECULES 

The mass of one Ping-Pong The mass of one golf ball is 2 grams. ball is 40 grams. 

A Ping Pong ball is 2/to, or 1/20, as massive as a golf ball. 

A customer wants to buy a i i mixture of blue and red jelly beans. Each blue bean is twice as massive as each red bean. If the clerk measures out 5 pounds of red beans, how many pounds of blue beans must she measure out  

Was this your answer Because each blue jelly bean has twice the mass of each red one, the clerk needs to measure out twice as much mass of blues in order to have the same count, which means io pounds of blues. If the clerk did not know that the blue beans were twice as massive as the red ones, she would not know what mass of blues was needed for the i i ratio. Likewise, a chemist would be at a loss in seUiriy up a ctiernical reaction if stie did not know the relative masses of the reactants. 

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Chemists Use Relative Masses to Count Atoms and Molecules... 

How do chemists use the mole and molar masses to count numbers and relative numbers of atoms and molecules Relate your answer to the techniques you used to count rice, nuts, and washers. 

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