4. Which has more number of atoms, 100 grams of sodium or 100 grams of iron (given, atomic mass of Na = 23u, Fe = 56 u)?

Question

Asked by Vishal kumar | 2 years ago | 247

0 0

Class 9 Science Atoms and Molecules Add Answer

Calculate the number of aluminium ions present in 0.051g of aluminium oxide.

(Hint: The mass of an ion is the same as that of an atom of the same element. Atomic mass of Al = 27u)

Class 9 Science Atoms and Molecules View Answer

Calculate the number of molecules of sulphur (S8) present in 16g of solid sulphur.

Class 9 Science Atoms and Molecules View Answer

What is the mass of:

(a) 0.2 mole of oxygen atoms?

(b) 0.5 mole of water molecules?

Class 9 Science Atoms and Molecules View Answer

Convert into mole.

(a) 12g of oxygen gas

(b) 20g of water

(c) 22g of carbon dioxide

Class 9 Science Atoms and Molecules View Answer

What is the mass of -

(a) 1 mole of nitrogen atoms?

(b) 4 moles of aluminium atoms((Atomic mass of aluminium =27)?

(c) 10 moles of sodium sulphite (Na₂SO₃)?

Class 9 Science Atoms and Molecules View Answer

Accepted Answer

Given: Atomic mass of Na=23u, Atomic mass of Fe= 56u

To calculate the number of atoms in 100g of sodium:

23g of Na contains = 6.022 X 10²³ atoms

1g of Na contains = 6.022 X 10²³ atoms / 23

100g of Na contains = 6.022 X 10²³ atoms X 100 / 23

= 2.6182 X 10²⁴ atoms

To calculate the number of atoms in 100g of sodium:

56g of Fe contains = 6.022 X 10²³ atoms

1g of Fe contains = 6.022 X 10²³ atoms / 56

100g of Fe contains = 6.022 X 10²³ atoms X 100 / 56

= 1.075 X 10²⁴ atoms

Hence, through comparison, it is evident that 100g of Na has more atoms

Answered by Shivani Kumari | 2 years ago