A 0.258 g piece of potassium solid is placed inot water inside a coffee cup calorimeter resulting in a vigorous reaction. assume a total volume of 100 ml for the resulting solution. the temperature of the solution changes from 22 to 25.1 due to the reaction. how much heat in kj is generated per gram of potassium for this reaction? assume the density of the solution after the reaction is the same as the density of water

The chemical composition of soil varies with depth. an article in communications in soil science and plant analysis describes chemical analyses of soil taken from a farm in western australia. fifty specimens were each taken at depths 50 and 250 cm. at a depth of 50 cm, the average no3 concentration (in mg/l) was 88.5 with a standard deviation of 49.4. at a depth of 250 cm, the average concentration was 110.6 with a standard deviation of 51.5. find a 95% confidence interval for the difference in no3 concentrations at the two depths.