How many molecules of SO2 would be present per cubic metre if the world health organization has set a limit to the sulfur dioxide content of clean air of 3.10 X 10-6 mol of SO2 per cubic metre.?

To calculate the number of molecules of SO2 present per cubic meter, you can use Avogadro's number (6.022 x 10^23 molecules/mol). First, convert 3.10 x 10^-6 mol to molecules by multiplying by Avogadro's number to get 1.86 x 10^18 molecules of SO2 per cubic meter.