The amount of energy released is calculated by the product of heat of fusion and mass.
The formula of amount energy released is given by:
(1)
Here,
q is amount of energy released
L is heat of fusion ()
m is mass of water
Put all the given values in equation (1)
≅
Thus, amount of energy released is
When the student crushes sugar there there occurs an increase in the number of molecules or particles of sugar. This means that now more number of sugar particles (solute) are able to interact with water (solvent).
Therefore, there will be more number of collisions taking place between the solute and solvent molecules.
As a result, sugar will dissolve readily into water as there is an increase in interaction between solute and solvent particles.
Thus, we can conclude that when he crushes the sugar and then stirs it into the water then it will work as this leads to more interaction or collisions between the solute and solvent particles.
17.) C 4-methylhex-1-ene
5.) D oct-3-ol-5-en
First, divide the given mass of lead (ii) chloride by the molar mass of the compound. The molar mass is equal to 278.1 g/mol.
n = m/M
where n is the number of moles, m is the given mass, and M is the molar mass. Substituting the known values,
n = 473.7 g / 278.1 g/mol
n = 1.7 mols
Then, it is to be remember that as per Avogadro, every mol of a substance contains 6.022 x 10^23 formula units.
N = (1.7 mols)(6.022 x 10^23 formula units/mol)
N = 1.02 x 10^24 formula units
Answer: 1.02 x 10^24 formula units