Question

from 200 milligram of carbon dioxide 10^21 molecules are removed calculate mole of carbon di oxide left

Answer 1

mole of CO2 = 1/220 then molecules = 2.73 × 10^21 then remain molecules = 1.73×10^21 so remain mole = 2.8×10^-3

Answer 2

first convert mass of co2 into mole
200 mg co2 *(1gram co2 / 1000mg co2) =0.200 g co2 .
the molar mass of co2 = c (1 * 12) +2o ( 2 * 16 )= 44 g co2 per mole of co2.
0.200g co2 * ( 1 mole co2/ 44 g co2 )=0.00455 mole of co2.
one mole of co2 contains 6.022 * 10^ 23 particles.
0.00455 mole of co2* 6.022* 10^23 molecules co2 / 1 mole co2 ).
so, if you take away 1 * 10^ 21 molecules, you have left = 2.74 * 10^21 - 1.0 * 10^ 21 = 1.74 * 10 ^ 21 molecules co2.