# Calorimetry Prelab

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06.09.2019-127 views -Calorimetry Prelab Experiment 12

Calorimetry and Heat of Reactions

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PERFORMANCE GOALS:

1 ) To learn using of a calorimeter

2 . To find out how to acquire and manipulate data inside the computer three or more. To determine the calorimeter constant

5. To use Hess' Law to get the heat or perhaps formation of magnesium oxide

CHEMICAL OVERVIEW:

вЂўEnthalphy: (О”H): when substance or physical alterations occur in a constant pressure.

вЂўCalorimeter: can be an instrument with insulating wall space where the response happens. Eq. 1: queen rxn = -qsurrounding

вЂўHeat of capacity with the calorimeter: " Cp" has to be calculated at the outset of every calorimeter experiment in Joules/ В°C

Heat Ability of the Calorimeter:

The calorimeter constant is easily discovered by adding a fixed amount of hot water to a known volume of cold water and the change in temp for each documented, due to the Legislation of Energy Conservation the amount of high temperature released by hot water should be equal to how much heat soaked up by the chilly water: Eq. 2 q released( Sizzling Water) = -q soaked up (Cold Water)

If there is a discrepancy among these two principles use the next equation:

Eq. 3q= meters x spht x О”T

Where spht is the certain heat in the substance in J/ gВ°C

О”T is a temperature enhancements made on В°C

andm is the mass in grams

Mass of Cold Water|51. 20 g

Initial heat of cool water|20. a few В°C

Mass of sizzling water|49. 82 g

First temp of hot water|98. 2 В°C

Final temperature of the mixture|58. 3 В°C

Eq. 4qHot = mHot x sphtWater x О”THot

qHot = (4. 184 J/ В°C-g)(49. 82g)(58. 3 В°C-98. 2 В°C) = -8317 J

Eq. 5qCold sama dengan mCold back button sphtWater x О”TCold

qCold sama dengan (4. 184 J/ В°C-g)(51. 20g)(58. several В°C-20. 3 В°C) = 8142 J

8317-8142 sama dengan 175 joules

Cp sama dengan ( a hundred seventy five J ) / (58. 3 В°C - 20. 3 В°C)

Cp sama dengan 4. 6 J/ В°C

HEAT OF REACTIONS:

q released = -q soaked up

Eq. 6 q introduced = - (q remedy + q calorimeter )

Eq. 7 qSolution sama dengan mSolution x sphtWater back button О”TSolution

sphtsolution= 4. 184 J/ g В°C

Eq. 8q calorimeter= Cp by О”T

Eq. 9 q reaction sama dengan О”Hreaction

Hess's Rules

Hess's Law states the enthalpy of the reaction is independent of the actions that it takes to comes from reactants to products since enthalpy of reaction is a state function.

Point out Function-

depends on preliminary and final state but is not on the route taken

вЃѓTemperature

вЃѓVolume

вЃѓPressure

вЃѓEnergy

Mg (s) + .5 O2 (g) --> MgO ( s)

PRE-LAB PROJECT

1 . Anticipate the product, stability the concerns and write down thier net ionic equations to get the reactions:

a. Mg (s) + HCI (aq) --->

n. MgO (s) + HC: (aq) --->

2 . Write down thier reaction that represents the enthalpy of formation ( О”Hfor ) of water.

3. Use the stand of the thermodynamic data within your text publication to estimate the О”H for each with the three reactions

REMEMBER

Eq. 10 ( О”H В°rxn = ОЈ ( nО”H В°for )prod - ОЈ ( nО”H В°for )react

1)

2)

3)

some. Use Hess's Law incorporating the three molecular equations to calculate the О”Hrxn pertaining to the reaction in the formation of MgO.

PROCEDURE

A. TUNED OF THERMISTOR

1 .

installment payments on your

3.

some.

5.

6.

7.

N. DETERMINATION FROM THE HEAT CAPACITY OF THE CALORIMETER

1 )

2 .

three or more.

4.

6.

several.

8.

being unfaithful.

10.

C. REACTION OF MgO AND HCI

1 .

2 .

3.

four.

5.

6.

7.

almost eight.

9.

Deb. REACTION OF Mg AND HCI

1 .

installment payments on your

3.

some.

5.

6.

7.

At the. DATA AND CALCULATIONS

A. Calorimeter Continuous

Mass of Styrofoam glass with top + " spin " bar (g)|

Mass of cup with lid + spin club + 50mL of space temp. water (g)|| Initial Temp of Room Temp. Water ( В°C )|

Initial Temp of Warm Water( В°C )|

Total mass by the end (g)|

Worked out Heat produced by Water...