Question

Arrange the following in order of increasing masses of 1 mole of :
$CO_3^{2 - }$,$PO_4^{3 - }$,$SO_4^{2 - }$,$C{l^ - }$and ${S^{2 - }}$

Answer 1

1 mole of a substance is equal to the molar mass of compound. So, we will find the molar mass of each compound. Thus, we can know the mass of 1 mole of compound. After this, we can arrange them in the order.

Complete step by step solution:
We know that 1 mole of a substance is equal to the molar mass of compound. So, we will find the molar mass of each compound. Thus, we can know the mass of 1 mole of compound and then arrange in order of increasing masses.
The molar mass of a compound is the sum of mass of all the atoms of an element each multiplied by the number of atoms of each type present.
So, let us find molar mass of all compounds as -
The first molecule is $CO_3^{2 - }$. This is carbonate. It consists of one carbon atom and three oxygen atoms.
Thus, the molar mass of $CO_3^{2 - }$= $(1 \times 12 + 3 \times 16)$
molar mass of $CO_3^{2 - }$= (12 + 48)
molar mass of $CO_3^{2 - }$= 60 g
The next molecule is $PO_4^{3 - }$. The phosphate has one phosphorus atom and four oxygen atoms.
So, the molar mass of $PO_4^{3 - }$= $(1 \times 30 + 4 \times 16)$
molar mass of $PO_4^{3 - }$= (30 + 64)
molar mass of $PO_4^{3 - }$= 94 g
The next molecule is $SO_4^{2 - }$. The sulphate has one sulphur atom and four oxygen atoms.
So, the molar mass of $SO_4^{2 - }$= $(1 \times 32 + 4 \times 16)$
molar mass of $SO_4^{2 - }$= (32 + 64)
molar mass of $SO_4^{2 - }$= 96 g
The next is $C{l^ - }$. It has one chlorine atom.
So, the molar mass of $C{l^ - }$= $(1 \times 34)$
molar mass of $C{l^ - }$= 34 g
The last is ${S^{2 - }}$. It has one sulphur atom.
So, the molar mass of ${S^{2 - }}$= $(1 \times 32)$
molar mass of ${S^{2 - }}$= 32 g
If we arrange them in increasing order of molar mass then, we get-
${S^{2 - }}$<$C{l^ - }$<$CO_3^{2 - }$<$PO_4^{3 - }$<$SO_4^{2 - }$

So, the same is the order for mass of 1mole. So, the order is-
${S^{2 - }}$<$C{l^ - }$<$CO_3^{2 - }$<$PO_4^{3 - }$<$SO_4^{2 - }$

Note: It must be noted that according to mole concept, 1 mole of a substance is equal to molar mass of molecule or atomic mass of an atom or ion. Further, this quantity is also equal to $6.023 \times {10^{23}}$ number of atoms or molecules or ions present.