Question

From 200 mg of co2 10^21 molecules are removed how many moles of co2 are left

Answer 1

First of all we have to find out number of molecules present in 200mg of CO₂.

Given,
weight of CO₂ = 200mg = 200 × 10⁻³ g = 0.2g
molecular weight of CO₂ = 44g/mol
∴number of mole of CO₂ = 0.2/44

Now, number of molecules = number of moles × 6.023 × 10²³
= 0.2/44 × 6.023 × 10²³
= 0.027 × 10²³
= 2.7 × 10²¹

A/C to question,
10²¹ molecule are removed from 2.7 × 10²¹ molecules of CO₂.
so, number of molecules are left = (2.7 -1) × 10²¹ = 1.7 × 10²¹
∵ mole = number of molecules/6.023 × 10²³
= 1.7/6.023 × 10²¹⁻²³
= 0.28 × 10⁻² = 0.0028

Answer 2

Hi there...

Hope this helps...