A chemist weighed out 71.3 g of tin. Calculate the number of moles of tin she weighed out. Be sure your answer has the correct number of significant digits.

Which substance is a steroid? cholesterol fatty acid monosaccharide trans fat

Nitric acid can be formed in two steps from the atmospheric gases nitrogen and oxygen, plus hydrogen prepared by reforming natural gas. in the first step, nitrogen and hydrogen react to form ammonia: (g) (g) (g) in the second step, ammonia and oxygen react to form nitric acid and water: (g) (g) (g) (g) calculate the net change in enthalpy for the formation of one mole of nitric acid from nitrogen, hydrogen and oxygen from these reactions. round your answer to the nearest .

8. what happens to matter during a chemical reaction