For the reaction 2NH3(g) + O2(g) -> 2NO(g) + 3H2O(g). The reaction is run using 824 g NH3 and excess oxygen. How many moles of NO are formed? How many moles of H2O are formed?

Explanation:

Step One

Find the molar Mass of NH3

N =   14

3H =  3

Mass = 17

Step Two

Find the number of moles of NH3

mols = given mass / Molar Mass

given mass = 824 grams

molar mass = 17

mols = 824/17

mols =  48.47

Step Three

Find the moles of NO

Here you have to look at the balanced equation

Every 2 mols of HN3 produces 2 mols of NO

So the number of mols of NH3 = 48.47

The number of mols of  NO      = 48.47

Step Four

Find the mols of H2O

2 mols of NH3 produces 3 moles of H20

48.47 mols H20 produces x moles of H20

3/x = 2/48.47     Cross Multiply

2x = 3*48.47

2x = 145.41         Divide by 2

x = 145.41/2

x = 72.71            mols of water.

chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. these processes are called chemical reactions and, in general, are not reversible except by further chemical reactions. some reactions produce heat and are called exothermic reactions and others may require heat to enable the reaction to occur, which are called endothermic reactions. understanding chemical changes is a major part of the science of chemistry.