Question

Which has more atoms?

A) 2 grams of Helium

B) 0.10 moles of Helium

C) 9.0x1023 atoms of helium

D) 1/2 mole of Helium

Answer 1

A) molar mass of Helium = 4.0026 gm/mole then 2 gm helium = 2/4.0026 = 0.499675 mole of helium

According to avogadro's law 1 mole substance contain 6.022 X 10²³ atom then 0.499675 mole of helium =

6.022 X 10²³ X 0.499675 = 3.0 X 10²³ atom of helium

B) According to avogadro's law 1 mole substance contain 6.022 X 10²³ atom then 0.10 mole of helium =

6.022 X 10²³ X 0.10 = 6.022 X 10²² atom of helium

C) 9.0 X 10²³ atom

D)According to avogadro's law 1 mole substance contain 6.022 X 10²³ atom then 1/2 mole of helium =

6.022 X 10²³ X (1/2) = 3.0 11 X 10²³ atom of helium

Ans - C) 9.0 X 10²³ atoms of helium