How many moles of Fe2O3 are in 203 g of the compound?

How many grams of dry nh4cl need to be added to 2.50 l of a 0.800 m solution of ammonia, nh3, to prepare a buffer solution that has a ph of 8.53? kb for ammonia is 1.8*10-5. express your answer with the appropriate units?

Be able to identify the youngest and oldest rock layers in a model that includes fossils

What solid is not made of crystals?

Explain how crop rotation and cover crops are important to sustainable agriculture.

How are biotic factors different from abiotic factors in an environment? A. Biotic factors do not require water; abiotic do. B. Biotic factors are living; abiotic are not. C. Biotic factors are found everywhere; abiotic are not. D.

Fluorine and Nitrogen react to form a covalent molecule. Which best describes the molecule they will make? There are 3 Nitrogens and 1 Fluorine. Nitrogen will be the central atom. There are 3 Fluorines and 1 Nitrogen.

Which change will decrease the number of effective collisions during a chemical reaction? adding a catalyst increasing the surface area decreasing the temperature increasing the reactant concentrations increasing the volume of the reactants

Review this chemical equation: O2 + CH4---> CO2 + H2O Which answer best explains what must be done to make this equation comply with the law of conservation of mass?

the number of significant figures: 6.32 g a:2 b:3

One of the following properties was originally used to arrange elements on the periodic table, but is no longer used to organize the modern version. Which property fits this description?