The answer is: Dividing the number of molecules in the sample by Avogadro's number.
The Avogadro’s number is the number of atoms in 12 grams of the isotope carbon-12 (¹²C).
Na is Avogadro number or Avogadro constant (the number of particles, in this example carbon, that are contained in the amount of substance given by one mole).
The Avogadro number has value 6.022·10²³ 1/mol in the International System of Units; Na = 6.022·10²³ 1/mol.
For example:
N(Ba) = 2.62·10²³; number of atoms of barium.
n(Ba) = N(Ba) ÷ Na.
n(Ba) = 1.3·10²⁴ ÷ 6.022·10²³ 1/mol.
n(Ba) = 2.158 mol; amount of substance of barium.
Explanation:
A chemical reaction equation that contains same number of atoms on both reactant and product side is known as a balanced chemical reaction equation.
For example, 
Here, number of reactant molecules are as follows.
Na = 2
S = 2
Cd = 1
O = 4
Number of product molecules are as follows.
Na = 2
S = 2
Cd = 1
O = 4
As there are already equal number of atoms on both reactant and product side. Hence, the reaction equation is balanced.
Also, in this reaction both
and
are present as aqueous solution. And, CdS is the precipitate that is formed as it is the insoluble solid that forms.
is present in aqueous state.
The mole fraction of HNO3 is 0.225
<u>Explanation:</u>
<u>1.</u>Given data
Density = 1.429 /ml
Mass% = 63.01 g HNO3 / 100g of solution
The mass of 63.01 g is in 100 / 1.142 /ml of solution
Or 63.01 g in 55.7 mL
Molarity = 15.39 moles / L
Mass of water in 100g = 100 - 63.01=36.99 g
So 63.01 grams in 36.99 grams of water
So mass of HNO3 in 1000grams of water = 63.01* x 1000 / 36.99 = 1703
Moles of HNO3 in 1000g = 1703 / 63.01 = 27.03 moles
Molality = 27.03 molal (mole / Kg)
Mole fraction = Mole of HN03 / Moles of water + mole of HNO3
Mole of water = 62/ 18 = 3.44
Moles of HNO3 = 63.01 / 63.01 = 1.000
Mole fraction = 1.000 / 3.44 + 1.000 = 0.225
The mole fraction of HNO3 is 0.225
To answer this question, you need to know the Avogadro number. To find the amount of sugar molecule from mol unit you need to multiply it by the Avogadro number.
The calculation should be like this: <span>0.734 mol * 6.02*10^23 molecule/ mol= 4.41 * 10^23 molecule</span>