Question

Dry ice (above) is made from carbon dioxide gas at extremely low temperatures and very high pressures. A 0.25 g sample of dry ice contains molecules CO2:

Answer 1

Answer:To find the number of CO2 molecules in a 0.25 g sample of dry ice, we can use the Avogadro's number and the molar mass of CO2.The molar mass of CO2 is:12.01 g/mol (C) + 2(16.00 g/mol) (O) = 44.01 g/molThis means that 1 mole of CO2 contains 6.022 x 10^23 molecules.To find the number of moles in 0.25 g of CO2, we can use the molar mass:0.25 g / 44.01 g/mol = 0.005681 molFinally, we can use Avogadro's number to find the number of CO2 molecules:0.005681 mol x 6.022 x 10^23 molecules/mol = 3.422 x 10^21 CO2 moleculesTherefore, a 0.25 g sample of dry ice contains approximately 3.422 x 10^21 CO2 molecules.