- Calculate the number of magnesium atoms in 3.2 g of chlorophyll, if it contains 0.024% of magnesium. [Atomic mass of Mg = 24 u]
- Which law is also known as law of indestructibility of matter? Why?
- Amount of Mg present in 3.2 g of chlorophyll = 0.024% of 3.2 =
Number of moles of Mg =
1 mole of Mg contains 6.022 x 1023
Therefore, 3.2 x 10–5 moles of Mg will contain 3.2 x 10–5 x 6.022 x 1023 = 1.93 x 1019 atoms.
- The law of conservation of mass is also known as law of indestructibility of matter, because mass can neither be created nor be destroyed during a chemical reaction.