Calculate the number of particles in each of the following (a) 46g of Na atom.(b) 8g of O2 Molecules. (c) 0.1 moles of Carbon atom.
Answers
atomic mass of Na=23u
Number of particles=Number of Moles x N
⇒(given weight/ Gram atomic weight) x 6.023 x 10²³
=(46/23)x 6.023 x 10²³
=2x 6.023 x 10²³
⇒12.046 x 10 ²³Na particles
∴46 g of Na contains 12.044 x 10 ²³
b)8g of O2 moles
molecular mass of O2=32u
No. Of molecules in O2 molecules=(8/32) x 6.022 x 10²³⇒0.25 x 6.023 x 10 ²³
⇒1.5055x 10 ²³ molecules
∴8g of O2 contains 1.5055x 10²³ molecules
c)0.1 moles of Carbon atom
1mole of carbon atom = 12 g of carbon contains 6.022 x 10²³ carbon atoms
0.1 moles of carbon contain =0.1 x 6.023 x 10²³
⇒ 6.023x10²² carbon atoms
∴0. mole contains 6.023x10²² carbon atoms
Answer:
1) The molar mass of sodium atom is 23g. Thus there are 6.022 X 1023 atoms of sodium present in 23g of sodium. So
number of atoms present in 23g of sodium = 6.022 X 10^23
number of atoms present in 1g of sodium = (6.022 X 10^23) / 23
number of atoms present in 46g of sodium = (46 X 6.022 X 10^23) / 23
2) The molar mass of oxygen molecule is 32g. Thus there are 6.022 X 10^23 molecules of oxygen present in 32g of oxygen. So
number of molecules present in 32g of oxygen = 6.022 X 10^23
number of molecules present in 1g of oxygen = (6.022 X 10^23) / 32
number of molecules of oxygen present in 8g of oxygen molecule = (6.022 X 10^23 X 8) / 32 = 1.506 X 10^23
3) The molar mass i.e. the mass of one mole of carbon atom is 12g. Thus there are 6.022 X 10^23 atoms of carbon in one mole of carbon. So
number of atoms in one mole of carbon = 6.022 X 10^23
number of atoms in 0.1 moles of carbon = 6.022 X 10^23 X 0.1 = 6.022 X 10^22