Achemist adds 26.5g of ammonium chloride to 10g of sodium hydroxide, which follows the reaction below. assuming the reaction goes to completion, how much of which reactant is left in excess?

Answer :  The amount of reactant left in excess is 13.1075 grams.

Explanation : Given,

Mass of = 26.5 g

Mass of = 10 g

Molar mass of = 53.5 g/mole

Molar mass of = 40 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 mole of react with 1 mole of

So, 0.25 moles of react with 0.25 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.

Moles of remaining excess reactant = 0.495 - 0.25 = 0.245 moles

Now we have to calculate the mass of .

Therefore, the amount of reactant left in excess is 13.1075 grams.

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.

it means there are 3 atoms of oxygen