Three separate samples of an unknown gas were bubbled through water and collected in a closed container of variable volume. The masses of the gas samples were determined by measuring the mass of the flask containing the pure gas before and after each introduction of gas into the water/sealed container apparatus. Given that the atmospheric pressure was 776.5mmHg throughout, and the vapor pressure of water at the experimental temperature was 21.2mmHg, calculate the molecular weight of the unknown gas: Trial 1 Trial 2 Trial 3 Temperature (oC) 24.5 23.8 23.8 Initial Mass 12.4510g 12.3585g 12.2802g Final Mass 12.3585g 12.2802g 12.1708g Volume collected 40.15mL 33.62mL 45.34mL

100mg magnesium reacts with 20ml of 1.0m hcl

1. suppose a reaction mixture, when diluted with water, afforded 300 ml of an aqueous solution of 30 g of the reaction product malononitrile [ch2(cn)2], which is to be isolated by extraction with ether. the solubility of malononitrile in ether at room temperature is 20.0 g/100 ml, and in water is 13.3 g/100 ml. what weight of malononitrile would be recovered by extraction with (a) three 100-ml portions of ether and (b) one 300-ml portion of ether? suggestion: for each extraction, let x equal the weight extracted into the ether layer. in part (a), the concentration in the ether layer is x/100 and in the water layer is (30 x)/300; the ratio of these quantities is equal to k 20/13.3.

How many moles of al3+ ions are in 1.25 moles of al2o3