Question #38860

1 Answer
Mar 3, 2017

Answer:

The answer is B) #1# mole of silver

Explanation:

The idea here is that you need to convert everything to grams.

You already know that one of the samples contains #2# gram atoms of nitrogen. Now, a gram atom is used to denote the mass of a substance that contains #6.02 * 10^(23)# atoms.

Note that #6.02 * 10^(23)#, known as Avogadro's constant, represents the definition of a mole.

Simply put, a gram atom is the mass of a substance that contains #1# mole of atoms. In this case, #2# gram atoms of nitrogen will be equivalent to #2# moles of elemental nitrogen.

This means that the mass of the first sample will be

#2 color(red)(cancel(color(black)("moles N"))) * "14 g"/(1color(red)(cancel(color(black)("mole N")))) = "28 g"#

Keep in mind that the relative atomic mass is actually equivalent to its molar mass. So if nitrogen is said to have a relative atomic mass of #14#, its molar mass will be equal to #"14 g mol"^(-1)#.

The relative atomic mass of silver is said to be equal to #108#. This is equivalent to saying that #1# mole of silver atoms has a mass of #"108 g"#.

Now, a sample of any ideal gas that is being kept at a pressure of #"1 atm"# and a temperature of #0^@"C"# contains exactly #1# mole of gas and occupies #"22.4 L"#.

This implies that you're dealing with #1# mole of oxygen gas, #"O"_2#. Elemental oxygen has a molar mass of #"16 g mol"^(-1)#, which means that diatomic oxygen will have a molar mass of

#M_ ("M O"_2) = 2 xx "16 g mol"^(-1) = "32 g mol"^(-1)#

You can thus say that the sample of oxygen gas has a mass of #"32 g"#.

Finally, #6.02 * 10^(23)# atoms of carbon are needed in order to have #1# mole of carbon.

This means that the last sample will contain #1# mole of carbon and have a mass of #"12 g"# since carbon has a molar mass of #"12 g mol"^(-1)#.

Therefore, you will have

#"108 g Ag" > "32 g O"_2 > "28 g N" > "12 g C"#