A sample of Al2O3 decomposed to pure aluminum and oxygen. After decomposition, 20.0 mol of Al were recovered. How many moles of Al2O3 were decomposed?

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.

How many moles are present in 10.5 grams of nacl?

Aresearcher wants to experiment with an element that reacts like phosphorus (p) but has a greater atomic mass. which element should the researcher select for the experiment?