with contact process how much reactant would be needed to produce 1-kg of the main product.
You have posted this more than once. You might get some help if you were less succinct in writing the question AND if you told us how you might go about solving it. Here is a link that will give you a step by step method for solving stoichiometry problems.
http://www.jiskha.com/science/chemistry/stoichiometry.html