Question

A sample of glucose contains 1.250x10^21 carbon atoms, how many atoms of hydrogen does it contain?

Answer 1

Answer:

Hydrogen = 2.5 * 10^21

Explanation:

Chemical Formula Glucose: C₆H₁₂O₆

One of the ways you could do  this is to notice that for every carbon atom there are two Hydrogen atoms. You can state this more formally by using the formula to set up a ratio: 12/6 = hydrogen to Carbon

So if there are 1.250 * 10^21 Carbon atoms in the Glucose sample, then there will be twice as many hydrogen atoms.

H = 2 * 1.25 * 10^21 = 2.5 * 10^21 atoms

You could do this more formally by setting up a proportion.

6 Carbon / 12 Hydrogen = 1.25*10^21 /  x         Cross Multiply

6*x = 12 * 1.25*10^21                                           Combine the right

6x = 1.5 * 10^22                                                  Divide by 6

x = 2.5 * 10^21