A sample of N2(g) effuses through an orifice in 125 seconds. How long will it take the same amount of propane, C3H8, to effuse through the same orifice under the same conditions

Which aqueous solution of ki freezes at the lowest temperature? 1) 1 mol of ki in 500. g of water 2) 2 mol of ki in 500. g of water 3) 1 mol of ki in 1000. g of water 4) 2 mol of ki in 1000. g of water