Which reactant, and how many grams of it, is left over after 16.0 g of mno2 (fw = 86.9 g/mol) and 30.0 g of hcl (fw = 36.5 g/mol) react according to the following chemical equation? mno2 + 4 hcl ® mncl2 + cl2 + 2 h2o3.1 g hcl23.3 g hcl4.02 g mno28.0 g mno212.1 g mno2

Answer : The HCl reactant is left over in the reaction and the left over amount of HCl is, 3.1 grams

Explanation : Given,

Mass of = 16.0 g

Mass of = 30.0 g

Molar mass of = 87 g/mole

Molar mass of = 36.5 g/mole

First we have to calculate the moles of and .

Now we have to calculate the limiting and excess reagent.

The balanced chemical reaction is,

From the balanced reaction we conclude that

As, 1 moles of react with 4 mole of

So, 0.184 moles of react with moles of

From this we conclude that, is an excess reagent because the given moles are greater than the required moles and is a limiting reagent and it limits the formation of product.

The excess moles of HCl = 0.822 - 0.736 = 0.086 mole

Now we have to calculate the mass of .

Therefore, the HCl reactant is left over in the reaction and the left over amount of HCl is, 3.1 grams

"standard molar enthalpy:

h2o ( liquid water ) : - 285.8 kj/mole

h2o ( water vapor ) : - 241.8 kj / mole.

δhrxn = - 241. 8 - ( - 285.8 )= -241.8 + 285.8 = 44.0

answer: 44.0 kj"