Question

Find the number of atoms in 48 g of ozone at NTP.

Answer 1

Hint: 48 g of ozone is equal to 1 mole and 1 mole of ozone contains $6.022\times {{10}^{23}}$ molecules of ozone. One molecule of ozone contains 3 atoms of oxygen. NTP indicates normal temperature and pressure.

Complete step by step solution:
Amount of substance that contains the same number of particles as atoms in exactly 12g of carbon-12 isotope is 1 mole.
Mass of carbon-12 is $1.99\times {{10}^{-23}}$ g. one mole of carbon has weight 12g so the number of atoms present in 1 mole is $6.022\times {{10}^{23}}$atoms/mol. This number is called Avogadro’s constant.
The molar mass of one mole of a substance.
NTP indicates normal temperature and pressure. NTP is defined as pressure as one atmosphere and temperature 20 degree Celsius.
The number of moles can be calculated by dividing the given mass to molar mass.
The molar mass of ozone is 48g as each oxygen atom has mass has 16g and there are three oxygen atoms.
So one mole of ozone is equal to 48g.
As we know, 1 mole of ozone contains $6.022\times {{10}^{23}}$ molecules of ozone.
Each ozone molecule has three oxygen atoms.
as 1 molecule of ozone contains three atoms of oxygen, so $6.022\times {{10}^{23}}$ molecules of ozone contains $18.066\times {{10}^{23}}$ atoms.

Note: STP indicates standard temperature and pressure. Temperature is 25 degrees Celsius and pressure is 1 atmosphere. At this temperature and pressure, 1 mole of gas occupies 22.4 litres of volume. 1 mole of gas is equal to its molar mass and contains $6.022\times {{10}^{23}}$ molecules, atoms or ions. The molar mass of ozone is 48g.