Question

What will be the weight of \[CO\] having the same number of oxygen atoms as present in \[22g\] of \[C{O_2}\] ?
A.\[28g\]
B.\[22g\]
C.\[44g\]
D.\[72g\]

Answer 1

Hint: To answer the question, first find the mass of the \[C{O_2}\] , then find the number of oxygen atoms that are present in the \[C{O_2}\] molecules and the moles of oxygen. This approach will help you to reach the answer.

Complete answer:
Let us start by the mass of \[C{O_2}\]= \[44g\]
In a molecule of \[C{O_2}\] the number of oxygen present is = \[2\]
This means that there are \[2mol\] of oxygen present in \[44g\] of \[C{O_2}\]
Here the given quantity is \[22g\] of \[C{O_2}\]
 therefore in \[22g\] of \[C{O_2}\] number of \[moles\] of oxygen is = \[\dfrac{2}{{44}} \times 22 = 1mol\]
 \[1mol\] \[CO\]= \[28g\]
Therefore\[28g\] of \[CO\] contains \[1mol\]oxygen atom
And hence the correct answer is option A.

Additional information: One mole is the amount of a substance that contains as many particles or entities as there are atoms in exactly \[12g\] of the \[^{12}C\] isotopes. It is similar to the quantities as we denote one dozen or a gross for \[12\] or \[144\] items. The S.I. unit is \[mole\] and the symbol for mole is \[mol\]. The mole of a substance always contains the same number of entities, no matter what the substance may be. This is represented by which is equal to \[6.022 \times {10^{23}}atoms/mol\]
Also the molar mass is the mass of one mole of a substance in \[grams\]. The molar mass in \[grams\] is numerically equal to atomic or molecular formula mass in \[u\]
The number of moles is given by the formula-
\[No.{\text{ }}of{\text{ }}moles = \dfrac{{Given{\text{ mass}}}}{{Molar{\text{ mass}}}}\]

Note:
Atoms and molecules are extremely small in size and their numbers in even a small amount of any substance is really very large. To handle such large numbers, a unit of similar magnitude is required. Therefore the mole concept was introduced.