Suppose you are investigating the reaction: m(s) + 2 hcl(aq) → mcl2(aq) + h2(g). you weigh out a 0.295 gram piece of metal and combine it with 65 ml of 1.00 m hcl in a coffee-cup calorimeter. if the molar mass of the metal is 57.78 g/mol, and you measure that the reaction absorbed 104 j of heat, what is the enthalpy of this reaction in kj per mole of limiting reactant? enter your answer numerically to three significant figures in units of kj/mol.

The enthalpy of the reaction is

Explanation:

To calculate the number of moles, we use the equation:

  ....(1)

Given mass of metal = 0.295 g

Molar mass of metal = 57.78 g/mol

Putting values in above equation, we get:

We are given:

Volume of hydrochloric acid = 65 mL = 0.065 L   (Conversion factor: 1 L = 1000 mL)

Molarity of the solution = 1 moles/ L

Putting values in above equation, we get:

By Stoichiometry of the reaction:

1 mole of metal reacts with 2 moles of hydrochloric acid..

So, 0.0051 moles of metal will react with = of hydrochloric acid.

As, given amount of hydrochloric acid is more than the required amount. So, it is considered as an excess reagent.

Thus, metal is considered as a limiting reagent because it limits the formation of product.

By Stoichiometry of the reaction:

If 1 mole of metal absorbs 104 J of heat

Then, 0.0051 moles of metal will absorb = of heat.

Converting joules to kilo joules, we use the conversion factor:

Converting the given value in kilo joules, we get:

Hence, the enthalpy of the reaction is

no but i do not usually comment or use my voice that much when it comes to social media