In an air-carbon dioxide mixture in a tube of diameter 10 cm at 298 K and 202.6 kPa, the partial pressure of CO2 at two planes 3 mm apart are 30.4 and 50.6 KPa respectively. The diffusivity of CO2 in air at 298 K and 202.6 kPa is 8.2*10 m 2 /s Calculate the rate of transfer of CO2 across the two planes, assuming: a. Equimolecular counter diffusion. b. Diffusion of CO2 through a stagnant air layer. c. In case 4a) what is the diffusion of coin moles per minute. 4+4+21

In a laboratory experiment, a fermenting aqueous solution of glucose and yeast produces carbon dioxide gas and ethanol. the solution was heated by burning natural gas in a bunsen burner to distill the ethanol that formed in the flask. during the distillation, the ethanol evaporated and then condensed in the receiving flask. the flame of the burner was kept too close to the bottom of the flask and some of the glucose decomposed into a black carbon deposit on the inside of the flask. during this experiment the following changes occurred. which of these changes involved a physical change and not a chemical change? check all that apply. 1-condensation of ethanol 2-evaporation of ethanol 3- formation of carbon dioxide gas from glucose burning of natural gas 4-formation of ethanol from glucose by yeast 5-formation of a carbon deposit inside the flask

Acontrol during an experiment. might change remains constant does not exist does change

On the periodic table, elements are arranged by which of the following. a. mass numbers. b. increasing atomic number. c. alphabetical order. or d. density