# How do you find the enthelphy change per mole of magnesium?

• Chemistry
• Naru1019
In summary, the conversation is about a calorimetry experiment where 0.5 grams of magnesium is dissolved in 100.0 ml of diluted HCL at an initial temperature of 29.50 C, resulting in a final temperature of 46.18 C. The question is about calculating the enthalpy change per mole of magnesium, which is solved by calculating the moles of magnesium consumed and using the formula H = q/mcΔt. The final answer is 338.99 KJ/mol.
Naru1019

## Homework Statement

In this calorimetry experiment, O.5 grams of magnesium is dissolved in 100.0 ml (100.0g) of diluted HCL (0.1mol/L) at an initial temperature of 29.50 C. The final temperature is 46.18 C.

Q: Calculate the enthalpy change per mole of magnesium.

## Homework Equations

I'm really confused about how will i get the the enthalpy change per mole for magnesium. Would it be the same as getting the enthalpy change per mole for magnesium chloride, because that's how i treated it and i don't think its the right answer. Can someone please help me?

## The Attempt at a Solution

C) In this calorimetry experiment, O.5 grams of magnesium is dissolved in 100.0 ml (100.0g) of diluted HCL (0.1mol/L) at an initial temperature of 29.50 C. The final temperature is 46.18 C.

The enthalpy change per mole of magnesium:

mass of mg = 0.5 grams
Molar mass of mg = 24.21g/mol
moles of mg = (0.5grams)/(24.31g/mol)
= .0206 moles of Mg

H = q
(Mg dissolving) = (calorimeter water)

H = n Hsol and q=mc t

mHCL = 100grams

cwater = 4.18

T = 46.18-29.50 = 16.18

n Hsol = mc T

Hsol(mg)= (mc T)/n
= (100gramsX4.18 J/g C X16.68C)/(.0206)
= 338990.3092 Joules
= 338.99 KJ/mol

I am not sure what you mean - you (correctly) calculated change per one mole of Mg consumed. That's it.

## 1. What is enthalpy change per mole of magnesium?

Enthalpy change per mole of magnesium is the amount of energy released or absorbed when one mole of magnesium undergoes a chemical reaction. It is a measure of the heat energy involved in the reaction.

## 2. How do you calculate enthalpy change per mole of magnesium?

To calculate enthalpy change per mole of magnesium, you need to know the enthalpy change of the reaction and the number of moles of magnesium involved. The enthalpy change per mole of magnesium can be determined by dividing the enthalpy change by the number of moles of magnesium.

## 3. What is the unit of enthalpy change per mole of magnesium?

The unit of enthalpy change per mole of magnesium is joules per mole (J/mol). This is the SI unit for energy per amount of substance.

## 4. Why is enthalpy change per mole of magnesium important?

Enthalpy change per mole of magnesium is important because it helps us understand the energy changes that occur during a chemical reaction. It can also provide information about the efficiency of a reaction and the amount of heat that can be harnessed from it.

## 5. How do you experimentally determine enthalpy change per mole of magnesium?

To experimentally determine enthalpy change per mole of magnesium, you would need to conduct a reaction involving magnesium and measure the change in temperature. Using the temperature change and the known heat capacity of the reaction vessel, you can calculate the enthalpy change per mole of magnesium using the formula q = mcΔT, where q is the heat energy, m is the mass of the reaction vessel, c is the heat capacity, and ΔT is the change in temperature.

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