Question #c7952

1 Answer
Jul 11, 2017

Answer:

#44.009# #"amu"#

Explanation:

To calculate the mass of one individual molecule of #"CO"_2#, we need to

  1. Multiply the atomic mass of carbon by however many carbon atoms are in the compound (1)

  2. Multiply the atomic mass of oxygen by however many oxygen atoms are in the compound (2)

  3. Sum the total

1.

If we look at a periodic table, the mass number underneath the carbon symbol should read

#color(red)(12.011# #color(red)("amu"#

We multiply this value by the number of #"C"# atoms in the compound to find the total mass of carbon in one molecule:

#(1)(color(red)(12.011)color(white)(l)color(red)("amu")) = color(red)(12.011# #color(red)("amu"#

2.

We now do the same exact process for oxygen. Its atomic mass is

#color(green)(15.999# #color(green)("amu"#

There are #2# atoms of oxygen per molecule of carbon dioxide:

#(2)(color(green)(15.999)color(white)(l)color(green)("amu")) = color(green)(31.998# #color(green)("amu"#

3.

The mass of one molecule of #"CO"_2# is the sum of the masses of the constituent elements:

#"mass CO"_2 = color(red)(12.011# #color(red)("amu"# #+ color(green)(31.998# #color(green)("amu"# #= color(blue)(44.009# #color(blue)("amu"#