Please answer all of these questions for me thank you

Nitrogen dioxide reacts with water to form nitric acid and nitrogen monoxide according to the equation: 3no2(g)+h2o(l)→2hno3(l)+no(g) part a suppose that 4.2 mol no2 and 0.50 mol h2o combine and react completely. which reactant is in excess? express your answer as a chemical formula. nothing

Calculate the number of moles of ethane in 100 grams

What is the molar mass of the anhydrous compound? answer using four significant figures. 36.02 g/mol 120.15 g/mol 156.12 g/mol