Question

In lab you measure out $87.25{\text{ }}g$of ${C_4}{H_8}{O_4}$ for an experiment. How many mol is this?

Answer 1

As we know that, $1$mole of any atom or molecule or ion contains Avogadro’s number (${N_A}$ ) of molecule
So, $1\,mole\, = \,6.022\, \times \,{10^{23}}\,atoms$
Therefore, for $1$ molecule will be;
$1\,\,atoms\, = \,\dfrac{1}{{6.022\, \times \,{{10}^{23}}}}\,moles$
So, the answer will be;
$1\,atoms\, = 1.66\, \times \,{10^{ - 24}}\,moles$

Complete step-by-step answer: First, we need to calculate the number of moles of ${C_4}{H_8}{O_4}$;
As we know that, the number of moles will be equal to the given mass divided by the molecular mass a compound.
Hence, the formula will be as follows,
$n\,\, = \,\,\dfrac{{mass}}{{molar\,mass}}$
Where,
$n\, =$ the amount in moles $(mol)$
Mass will be in the terms of$\;(g)$
Molar mass will be in the terms of $\;(g/mol)$
So, we need to calculate the moles of ${C_4}{H_8}{O_4}$ .
first, we need to calculate the molar mass of ${C_4}{H_8}{O_4}$and then we need to calculate the moles.
Let’s calculate the molar mass of this compound ${C_4}{H_8}{O_4}$;
The molar mass of carbon $= \,12\,g/mol$
We have four carbons so the overall molar mass for carbon will be;
$= \,12\, \times \,4\, = \,48\,g/mol$
The molar mass of hydrogen $= \,1.0\,g/mol$
We have eight hydrogens so the overall molar mass for hydrogen will be;
$= \,1\, \times \,8\, = \,8\,g/mol$
The molar mass of oxygen $= \,16\,g/mol$
We have four oxygen so the overall molar mass for oxygen will be;
$= \,16\, \times \,4\, = \,64\,g/mol$
Now the total molar mass of ${C_4}{H_8}{O_4}$ will be;
$= \,48\, + \,8\, + 64$
$= \,120\,g/mol$
Now, the given mass of{C_4}{H_8}{O_4}$$$$ = \,87.25{\text{ }}g
Let’s substitute in the values;
$n\,\, = \,\,\dfrac{{\,87.25\,g}}{{120\,g/mol}}\,$
$= \,0.727\,moles$
So, for the $87.25{\text{ }}g$ of ${C_4}{H_8}{O_4}$is $0.727\,moles$

Note: A mole is a unit measurement for the amount of substance in the international system of units i.e., SI unit. A mole of a particle or a mole of a substance is defined as $6.02214076 \times {10^{23}}$ of a chemical unit, that can be ions, atoms, molecules, etc. Originally it was defined as, the number of atoms in $12{\text{ }}g$ of carbon-12.