How many water molecules are there in 5.18 g of Water? How many ammonia molecules are there in 3.25 g of ammonia?
How many Chlorine molecules are there in 2.25 g of Chlorine?
Calculate the mass of 2.2 x 10 23 Sodium Hydroxide formula units
Calculate the mass of 2.8 x 10 23 sulphuric acid formula units

≈

1.2

⋅

10

24

atoms of hydrogen

Explanation:

Water has a molar mass of

18.01528

g/mol

≈

18

g/mol

.

So, in

18

g

of water, there will be

18

g

18

g

/mol

=

1

mol

Since water has a chemical formula of

H

2

O

, there will be

2

moles of hydrogen in every mole of water.

In one mole of water, there will exist approximately

6.02

⋅

10

23

water molecules.

So, there will be a total of

6.02

⋅

10

23

⋅

2

≈

1.2

⋅

10

24

hydrogen atoms.

answer : one can design an experiment using a liquid and an additive that can be added to the liquid and observe the chemical changes in the reaction species.

one would need a beaker which is filled with a known amount of the liquid in which thermometer is placed to measure the temperature changes; after addition of the additive to the liquid solution one can note down the temperature change and find whether the reaction is endothermic or exothermic in nature. by subtracting the initial temperature value with the final temperature one can find the temperature changes.

various combinations of liquid and additive can be used. liquid in this case can be a known quantity of water and additives can be epsom salt or without epsom salt the experiment can be conducted to notice the changes. water and ice, hydrogen peroxide and dry yeast, vinegar and baking soda,etc.