To determine the mass of 438 molecules of CO2 (carbon dioxide), you need to use the molar mass of CO2 and the Avogadro's number.The molar mass of CO2 is 12.01 + 2(16.00) = 44.01 g/mol.Avogadro's number is the number of particles (atoms, molecules, etc.) in one mole of a substance, and is equal to 6.022 x 10^23 particles/mol.To calculate the mass of 438 molecules of CO2, we can use the following steps:Convert the number of molecules to moles:438 molecules / 6.022 x 10^23 molecules/mol = 7.277 x 10^-22 molCalculate the mass using the molar mass:Mass = moles x molar mass
Mass = 7.277 x 10^-22 mol x 44.01 g/mol = 3.205 x 10^-20 gTherefore, the mass of 438 molecules of CO2 is 3.205 x 10^-20 grams (or approximately 0.00000000000000000003205 grams).