Difference between revisions of "ChemCollective-Virtual-Labs/C3/Heat-of-Reaction/English"

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(Created page with " {| border =1 |'''Visual Cue''' |''' Narration''' |- | '''Slide Number 1''' '''Title Slide''' | Welcome to this spoken tutorial on '''Heat of Reaction ''' using ''' Vlabs'''...")
 
 
(3 intermediate revisions by the same user not shown)
Line 15: Line 15:
 
| In this tutorial, we will learn to,
 
| In this tutorial, we will learn to,
  
−
Determine heat change for the neutralisation of Sodium hydroxide (NaOH) and Hydrochloric acid(HCl).Calculate heat of reaction for three different reactions.
+
Determine heat change for the neutralisation of Sodium hydroxide (NaOH) and Hydrochloric acid(HCl).
 +
 
 +
Calculate heat of reaction for three different reactions.
  
 
|-
 
|-
Line 23: Line 25:
  
  
−
'''Rx1: NaOH(s) +H<sub>2</sub>O(l) -> Na<sup>+</sup>(aq) + OH<sup>-</sup>(aq)'''
+
'''Rx1: NaOH(s) +H<sub>2</sub>O(l) ->'''
 +
 
 +
'''Na<sup>+</sup>(aq) + OH<sup>-</sup>(aq)'''
 +
 
 +
 
 +
'''Rx2: NaOH (s) + HCl (aq) -> '''
  
 +
'''Na<sup>+</sup>(aq) + Cl<sup>-</sup>(aq)+H<sub>2</sub>O '''
  
−
'''Rx2: NaOH (s) + HCl (aq) -> Na<sup>+</sup>(aq) + Cl<sup>-</sup>(aq)+H<sub>2</sub>O '''
 
  
 +
'''Rx3: NaOH (aq) + HCl (aq) ->'''
  
−
'''Rx3: NaOH (aq) + HCl (aq) -> Na<sup>+</sup>(aq) + Cl<sup>-</sup>(aq) +H<sub>2</sub>O(l)'''
+
'''Na<sup>+</sup>(aq) + Cl<sup>-</sup>(aq) +H<sub>2</sub>O(l)'''
  
 
| The three reactions are shown here.
 
| The three reactions are shown here.
Line 57: Line 65:
 
ChemCollective Vlabs version 2.1.0
 
ChemCollective Vlabs version 2.1.0
  
−
Java version 8
+
Java version 8.
  
 
|-
 
|-
Line 66: Line 74:
  
 
|-
 
|-
−
| Click on '''File->Load homework'''.
+
|Click on '''File->Load homework'''.
  
  
Line 77: Line 85:
 
'''Default Lab setup ''' dialog box opens.
 
'''Default Lab setup ''' dialog box opens.
  
−
In the box select '''Thermochemistry'''.
+
In the box, select '''Thermochemistry'''.
  
  
−
Double click on '''Heats of the reaction- Hess’ Law''' option.
+
Double click on '''Heats of the reaction- Hess’s Law''' option.
  
 
|-
 
|-
−
| Click on '''Stockroom Explorer''' and select '''problem description''' option.
+
| Click on '''Stockroom Explorer''' and select '''Problem Description''' option.
 
| Click on '''Problem Description''' in '''Stockroom Explorer'''.
 
| Click on '''Problem Description''' in '''Stockroom Explorer'''.
  
Line 138: Line 146:
  
  
−
'''Rx1: NaOH(s) +H<sub>2</sub>O(l) -> Na<sup>+</sup>(aq) + OH<sup>-</sup>(aq)'''
+
'''Rx1: NaOH(s) +H<sub>2</sub>O(l) ->'''  
  
 +
'''Na<sup>+</sup>(aq) + OH<sup>-</sup>(aq)'''
  
−
'''Rx3: NaOH(aq) + HCl(aq) -> Na<sup>+</sup>(aq) + Cl<sup>-</sup>(aq) +H<sub>2</sub>O(l)'''
 
  
−
'''<nowiki>--------------------------------------------</nowiki><nowiki>----------------------------------</nowiki>'''
+
'''Rx3: NaOH(aq) + HCl(aq) ->'''
  
 +
''' Na<sup>+</sup>(aq) + Cl<sup>-</sup>(aq) +H<sub>2</sub>O(l)'''
  
−
'''Rx2: NaOH (s) + HCl (aq) -> Na<sup>+</sup>(aq) + Cl<sup>-</sup>(aq)+H<sub>2</sub>O '''
+
-------------------------------------------------------------------
 +
 
 +
 
 +
'''Rx2: NaOH (s) + HCl (aq) ->'''
 +
 
 +
'''Na<sup>+</sup>(aq) + Cl<sup>-</sup>(aq)+H<sub>2</sub>O '''
  
 
| Sum of Heats of reactions for,
 
| Sum of Heats of reactions for,
Line 156: Line 170:
 
|-
 
|-
 
|  Go back to '''Workbench'''
 
|  Go back to '''Workbench'''
−
| Let us go back to '''Workbench.'''
+
| Let us go back to '''Workbench'''.
  
  
Line 164: Line 178:
  
 
|-
 
|-
−
| From the '''Stockroom Explorer''',  
+
|From the '''Stockroom Explorer''',  
  
 
Double-click on '''Distilled water''' .
 
Double-click on '''Distilled water''' .
Line 187: Line 201:
 
|-
 
|-
 
|Click on '''select tools''' icon, double-click on '''Scale'''.
 
|Click on '''select tools''' icon, double-click on '''Scale'''.
−
| From the instrument menu, select a '''Weighing Boat ''' and a ''' Scale.'''
+
| From the instrument menu, select '''Weighing Boat ''' and a ''' Scale'''.
  
 
|-
 
|-
Line 207: Line 221:
 
| Weigh 1 gram of''' Sodium hydroxide''' using '''Weighing Boat'''.
 
| Weigh 1 gram of''' Sodium hydroxide''' using '''Weighing Boat'''.
  
−
Place the '''Weighing Boat''' on the '''Scale''', click on '''TARE. '''
+
Place the '''Weighing Boat''' on the '''Scale''', click on '''TARE'''.
  
 
|-
 
|-
−
| Drag '''Sodium hydroxide''' bottle over to '''Weighing Boat'''.
+
|Drag '''Sodium hydroxide''' bottle over to '''Weighing Boat'''.
  
 
Type 1 in the '''Transfer amount''' input bar.
 
Type 1 in the '''Transfer amount''' input bar.
Line 230: Line 244:
  
  
−
Click on '''pour'''.
+
Click on '''Pour'''.
  
 
|-
 
|-
Line 272: Line 286:
 
Record the highest temperature on the '''thermometer'''.
 
Record the highest temperature on the '''thermometer'''.
  
−
'''Thermometer''' shows 30.29 degrees '''Celsius.'''
+
'''Thermometer''' shows 30.29 degrees '''Celsius'''.
  
 
|-
 
|-
Line 304: Line 318:
 
'''q = m * s * ∆T'''
 
'''q = m * s * ∆T'''
  
−
wherein 'm' is the mass of the reactants,  
+
wherein 'm' is mass of the reactants,  
  
 
's' is the specific heat of the product and  
 
's' is the specific heat of the product and  
Line 313: Line 327:
 
|  '''Slide Number 9'''
 
|  '''Slide Number 9'''
  
−
'''Reaction-1 (Rx1)'''
+
'''Calculation of heat of reaction Rx1'''
  
  
Line 330: Line 344:
  
 
|-
 
|-
−
| ΔH = q/moles of NaOH
+
| '''Slide Number 10'''
 +
 
 +
'''Calculation of heat of reaction Rx1'''
 +
 
 +
ΔH = q/moles of NaOH
  
 
Number of moles of NaOH is =1/40 = 0.025.
 
Number of moles of NaOH is =1/40 = 0.025.
Line 343: Line 361:
  
 
|-
 
|-
−
|  Click on Foam Cup and Graduated Cylinder.
+
|  Click on '''Foam Cup''' and '''Graduated Cylinder'''.
  
 
Press delete.
 
Press delete.
  
−
| Lets go back to workbench.
+
| Lets go back to '''workbench'''.
  
−
let us delete the used '''Foam Cup''' and '''Graduated Cylinder'''.
+
let us delete the used '''Graduated Cylinder''' and '''Foam Cup'''.
  
 
|-
 
|-
−
|  Double-click on glassware icon.  
+
|  Double-click on '''glassware''' icon.  
  
−
Double-click on 50 mL Graduated Cylinder and Foam Cup.
+
Double-click on 50 mL '''Graduated Cylinder''' and '''Foam Cup'''.
 
| We will now move on to demonstrate second exothermic reaction.
 
| We will now move on to demonstrate second exothermic reaction.
  
Line 362: Line 380:
  
 
|-
 
|-
−
|  From the chemical stockroom;
+
|  From the '''Chemical Stockroom''',
  
 
Double-click on 0.5 M '''Hydrochloric acid''' from the '''Strong-acids cabinet'''.
 
Double-click on 0.5 M '''Hydrochloric acid''' from the '''Strong-acids cabinet'''.
Line 372: Line 390:
  
 
|-
 
|-
−
| Drag the 0.5M Hydrochloric acid bottle over the Graduated Cylinder.
+
| Drag the '''0.5M Hydrochloric acid''' bottle over the '''Graduated Cylinder'''.
  
−
Type 50 in the transfer bar.
+
Type 50 in the '''Transfer bar'''.
  
 
Click on '''Pour'''.
 
Click on '''Pour'''.
−
| Transfer 50 mL of '''Hydrochloric acid''' into the '''Graduated Cylinder.'''
+
| Transfer 50 mL of '''Hydrochloric acid''' into the '''Graduated Cylinder'''.
  
 
|-
 
|-
−
| Drag '''Weighing boat''' and place it on the '''Scale'''.
+
|Drag '''Weighing boat''' and place it on the '''Scale'''.
  
 
Click on '''TARE'''.
 
Click on '''TARE'''.
Line 389: Line 407:
 
Type 1 in the '''Transfer amount''' input bar.
 
Type 1 in the '''Transfer amount''' input bar.
  
−
Click on '''Pour'''.Sodium hydroxide
+
Click on '''Pour'''.
−
 
+
 
| Weigh 1 gram of '''Sodium hydroxide''' using '''Weighing Boat'''.
 
| Weigh 1 gram of '''Sodium hydroxide''' using '''Weighing Boat'''.
  
Line 407: Line 424:
 
Drag the '''Graduated Cylinder''' over '''Foam Cup'''.
 
Drag the '''Graduated Cylinder''' over '''Foam Cup'''.
  
−
Type 50 in the transfer bar.  
+
Type 50 in the '''Transfer bar'''.  
  
 
Click on '''Pour'''.  
 
Click on '''Pour'''.  
Line 431: Line 448:
  
 
|-
 
|-
−
|  '''Slide Number 10'''
+
|  '''Slide Number 11'''
  
 
'''Calculation of heat of reaction for Rx2'''
 
'''Calculation of heat of reaction for Rx2'''
Line 457: Line 474:
 
|-
 
|-
 
|Select '''Foam Cup''' and '''Graduated Cylinder''', '''scale''' and '''0.5M HCl''' and press delete
 
|Select '''Foam Cup''' and '''Graduated Cylinder''', '''scale''' and '''0.5M HCl''' and press delete
−
|Delete the used apparatus and chemicals from the workbench.
+
|Delete the used apparatus and chemicals from the '''Workbench'''.
  
 
|-
 
|-
 
|Double-click on '''Glassware''' icon.  
 
|Double-click on '''Glassware''' icon.  
  
−
Double-click on 25 mL '''Graduated Cylinder''' and '''Foam Cup'''.
+
Double-click on 25 mL '''Graduated Cylinder''' and a '''Foam Cup'''.
  
  
Line 502: Line 519:
 
Double click on '''1.0 M Hydrochloric acid'''.
 
Double click on '''1.0 M Hydrochloric acid'''.
  
−
Close the cabinet.
+
Close the '''cabinet'''.
  
  
Line 531: Line 548:
  
 
T1= 25<sup>o</sup> C  
 
T1= 25<sup>o</sup> C  
−
| Transfer 25 mL of Hydrochloric acid(HCl) into graduated cylinder A.
+
| Transfer 25 mL of '''Hydrochloric acid(HCl)''' into '''graduated cylinder A'''.
  
−
Pour the Hydrochloric acid(HCl) from graduated cylinder to Foam Cup.
+
Pour the '''Hydrochloric acid(HCl)''' from '''graduated cylinder''' to '''Foam Cup'''.
  
  
Line 563: Line 580:
  
 
T2 = 31.67 <sup>o</sup> C
 
T2 = 31.67 <sup>o</sup> C
−
| Click on Foam Cup.
+
| Click on '''Foam Cup'''.
  
 
Allow the reaction to take place for a few seconds.
 
Allow the reaction to take place for a few seconds.
Line 570: Line 587:
  
  
−
Thermometer shows 31.67 <sup>o</sup> C.
+
'''Thermometer''' shows 31.67 <sup>o</sup> C.
  
 
|-
 
|-
−
|'''Slide Number 11'''
+
|'''Slide Number 12'''
  
 
'''Calculation of heat of reaction for Rx3'''
 
'''Calculation of heat of reaction for Rx3'''
Line 592: Line 609:
  
 
ΔH3 =-1.400/0.025 = -56.03 KJ mol<sup>-1</sup>
 
ΔH3 =-1.400/0.025 = -56.03 KJ mol<sup>-1</sup>
−
| Calculation of Molar Heat energy for reaction three is given here.
+
| Calculation of '''Molar Heat energy''' for reaction three is given here.
  
  
Line 598: Line 615:
  
 
|-
 
|-
−
|  '''Slide Number 12'''
+
|  '''Slide Number 13'''
  
−
Analysis of Results
+
'''Analysis of Results'''
  
  
−
This experiment is an example for Hess law.
+
This experiment is an example for '''Hess's law'''.
  
  
Line 614: Line 631:
 
ΔH2 = -102.47 KJ mol<sup>-1</sup>
 
ΔH2 = -102.47 KJ mol<sup>-1</sup>
  
−
| Let us now anlayse the results.
+
| Let us now analyze the results.
  
  
Line 625: Line 642:
  
  
−
Therefore this experiment illustrates Hess's law.
+
Therefore this experiment illustrates '''Hess's law'''.
 
|-
 
|-
 
|   
 
|   
Line 631: Line 648:
  
 
|-
 
|-
−
|  '''Slide Number 13'''
+
|  '''Slide Number 14'''
  
 
'''Summary'''
 
'''Summary'''
Line 637: Line 654:
  
  
−
Determined heat change for neutralization of Sodium hydroxide and Hydrochloric acid(HCl).
+
Determined heat change for neutralization of '''Sodium hydroxide'''
 +
 
 +
and '''Hydrochloric acid'''.
  
  
Line 643: Line 662:
  
 
|-
 
|-
−
|  '''Slide Number 14'''
+
|  '''Slide Number 15'''
  
 
'''Assignment '''
 
'''Assignment '''
Line 650: Line 669:
 
'''q = m * s  * ∆T '''
 
'''q = m * s  * ∆T '''
  
−
'''q = (50+4) x 4.2 x (-21.18) = 4803.62 Joules'''
+
'''q = (50+4) x 4.2 x (-21.18) = -4803.62 Joules'''
  
−
ΔH = 4803.62 /1000 = 4.803  
+
ΔH = -4803.62 /1000 = -4.803  
  
  
−
ΔH = 4.803/0.1 = 48.03 KJ mol<sup>-1</sup>
+
ΔH = -4.803/0.1 = -48.03 KJ mol<sup>-1</sup>
 
| For the assignment,
 
| For the assignment,
  
Line 661: Line 680:
  
  
−
Repeat Rx1 using 4 g of Sodium hydroxide and
+
Repeat Rx1 using 4 g of '''Sodium hydroxide''' and
  
 
calculate the heat of reaction.
 
calculate the heat of reaction.
  
  
−
Compare its value with the reaction in which 1 g of Sodium hydroxide was used.
+
Compare its value with the reaction in which 1 g of '''Sodium hydroxide''' was used.
  
  
 
|-
 
|-
−
|  '''Slide Number 15'''
+
|  '''Slide Number 16'''
  
 
'''About Spoken Tutorial project'''
 
'''About Spoken Tutorial project'''
−
| The video at the following link summarizes the '''Spoken Tutorial '''project.
+
| The video at the following link summarizes the '''Spoken Tutorial project'''.
−
 
+
  
 
Please download and watch it.
 
Please download and watch it.
  
 
|-
 
|-
−
|  '''Slide Number 16'''
+
|  '''Slide Number 17'''
  
 
'''Spoken Tutorial workshops'''
 
'''Spoken Tutorial workshops'''
−
| The '''Spoken Tutorial Project '''team:
+
| The '''Spoken Tutorial Project''' team:
  
 
conducts workshops using spoken tutorials and
 
conducts workshops using spoken tutorials and
Line 691: Line 709:
  
 
|-
 
|-
−
|  '''Slide Number 17'''
+
|  '''Slide Number 18'''
  
 
'''Forum for specific questions'''
 
'''Forum for specific questions'''
Line 710: Line 728:
  
 
|-
 
|-
−
|  '''Slide Number 18'''
+
|  '''Slide Number 19'''
  
 
'''Acknowledgement'''
 
'''Acknowledgement'''

Latest revision as of 13:26, 26 June 2021

Visual Cue Narration
Slide Number 1

Title Slide

Welcome to this spoken tutorial on Heat of Reaction using Vlabs.
Slide Number 2

Learning Objectives

In this tutorial, we will learn to,

Determine heat change for the neutralisation of Sodium hydroxide (NaOH) and Hydrochloric acid(HCl).

Calculate heat of reaction for three different reactions.

Slide Number 3

Reactions


Rx1: NaOH(s) +H2O(l) ->

Na+(aq) + OH-(aq)


Rx2: NaOH (s) + HCl (aq) ->

Na+(aq) + Cl-(aq)+H2O


Rx3: NaOH (aq) + HCl (aq) ->

Na+(aq) + Cl-(aq) +H2O(l)

The three reactions are shown here.
Slide Number 4

Pre-requisites


www.spoken-tutorial.org

To follow this tutorial you should be familiar with,

ChemCollective Vlabs interface.


If not, for relevant tutorials please visit our website.

Slide Number 5

System Requirement

Here, I am using

Mac OS 10.10.5

ChemCollective Vlabs version 2.1.0

Java version 8.

Click on Vlabs folder and

double-click on vlabs.exe file.

I have opened a Virtual Chemistry lab application window.
Click on File->Load homework.


Default Lab setup dialog box opens.

Thermochemistry >> Heat of the reaction

Click on File and select Load homework option.


Default Lab setup dialog box opens.

In the box, select Thermochemistry.


Double click on Heats of the reaction- Hess’s Law option.

Click on Stockroom Explorer and select Problem Description option. Click on Problem Description in Stockroom Explorer.
Cursor on Problem Description.

Scroll down the page and highlight the words Procedure, Processing Data, discussion and Conclusion.

The Problem Descriptionhere states that,


we have to determine and compare heat of reaction for 3 different reactions.


Scroll down the page and read,


Procedure, Processing the data, Discussion and Conclusion

Slide Number 6

Hess’s Law


∆ rH = ∆ r H 1 + ∆ r H 2 + ∆ r H 3 ….

This experiment is an illustration of Hess's law.


Which states that,


total heat change during the complete course of a reaction is same,


whether the reaction is made in one step or in several steps.


Heat of reaction is also known as Standard enthalpy change.

delta rH = delta r H 1 + delta r H 2 + delta r H 3 ,etc.

Slide Number 7

Hess’s law


ΔH1 + ΔH3 = ΔH2


Rx1 + Rx3= Rx2


Rx1: NaOH(s) +H2O(l) ->

Na+(aq) + OH-(aq)


Rx3: NaOH(aq) + HCl(aq) ->

Na+(aq) + Cl-(aq) +H2O(l)


Rx2: NaOH (s) + HCl (aq) ->

Na+(aq) + Cl-(aq)+H2O

Sum of Heats of reactions for,

Rx1 and Rx3 must be equal to heat of reaction for Rx2.

Rx=reaction

Go back to Workbench Let us go back to Workbench.


We will begin the first reaction.

Let us select the required chemicals and apparatus for the reaction.

From the Stockroom Explorer,

Double-click on Distilled water .


Go to Solids

Double click on Sodium hydroxide icons.

From the Chemical Stockroom,

Double-click on Distilled water.


Click on Solids cabinet and double-click on Sodium hydroxide.

Close the cabinet.

Click on Glassware icon. Double-click on 50 mL Graduated Cylinder. From the glassware menu, we will select a 50 mL Graduated Cylinder and a Foam Cup.
Click on select tools icon, double-click on Scale. From the instrument menu, select Weighing Boat and a Scale.
Drag the distilled water tank over to Graduated Cylinder.


In the Transfer amount input bar, Type 50. Click on Pour.

Keep the distilled water aside.

Transfer 50 mL of Distilled water to the Graduated Cylinder.

In the Transfer amount input bar, type 50 and click on Pour.

Drag Weighing Boat and place it on the scale.

Click on TARE.

Weigh 1 gram of Sodium hydroxide using Weighing Boat.

Place the Weighing Boat on the Scale, click on TARE.

Drag Sodium hydroxide bottle over to Weighing Boat.

Type 1 in the Transfer amount input bar.

Click on Pour.


Drag the Weighing Boat containing Sodium hydroxide bottle over Foam Cup.

Type 1 in the transfer amount input bar.

Click on Pour.

Drag the Sodium hydroxide bottle over the weighing boat.

Type 1 in Transfer amount input bar and click on Pour .


Transfer Sodium hydroxide from Weighing Boat to Foam Cup.


Click on Pour.

Click on Foam Cup.

Click on Solid radio button in the Solutions info panel, to see the weight in grams column.

Click on Foam Cup.

In the Solution info panel,

Click on Solid radio button and observe the weight in grams column.

Click on the Graduated Cylinder.

Drag the Graduated Cylinder to the Foam Cup.

Type 50 in the Transfer bar.

Click on Pour.


T1 = 25 o C.


Click on the Graduated Cylinder and record its temperature.


Thermometer shows the temperature as 25 degrees Celsius.


Drag the Graduated Cylinder over to the Foam Cup.


Type 50 in the Transfer Amount input bar and click on Pour.

T2 = 30.29 o C. Click on Foam Cup.

Record the highest temperature on the thermometer.

Thermometer shows 30.29 degrees Celsius.

Observe the grams column. Observe the grams column, it shows zero.


This is because all the Sodium hydroxide has now dissolved in water.

Lets see how to calculate heat of the reaction.
Slide Number 8

Heat of Reaction (q)

Formula


q = m * s *∆T

m = mass of the reactants

s = specific heat of the product

∆T = change in temperature in the reaction.

Heat of reaction (q) is calculated using the formula.

q = m * s * ∆T

wherein 'm' is mass of the reactants,

's' is the specific heat of the product and

'∆T' is the change in temperature in the reaction.

Slide Number 9

Calculation of heat of reaction Rx1


q = m * s * ∆T

m = 50 ml water + 1 g NaOH

s = 4.2 KJ/g

∆T = (T1- T2) = (25-30.29) = -5.29

q = (50+1) * 4.2 * (-5.29)

q= -1133.12/1000= -1.133 KJ.

Heat energy calculation for this reaction is given here.
Slide Number 10

Calculation of heat of reaction Rx1

ΔH = q/moles of NaOH

Number of moles of NaOH is =1/40 = 0.025.

ΔH1 =-.133/0.025 = -45.32 KJ mol-1

ΔH1= -45.32 KJ mol-1

Calculation of Molar Heat energy (delta H) in KJ/mol is given here.


delta H for reaction 1(Rx1) Sodium hydroxide is -45.32 KJ mol-1

Click on Foam Cup and Graduated Cylinder.

Press delete.

Lets go back to workbench.

let us delete the used Graduated Cylinder and Foam Cup.

Double-click on glassware icon.

Double-click on 50 mL Graduated Cylinder and Foam Cup.

We will now move on to demonstrate second exothermic reaction.

From Glassware menu,

Take a new 50 mL Graduated Cylinder and a Foam Cup.

From the Chemical Stockroom,

Double-click on 0.5 M Hydrochloric acid from the Strong-acids cabinet.

From the Chemical Stockroom, select Strong-acids cabinet.

Double click to get 0.5 M Hydrochloric acid.

Close the Cabinet.

Drag the 0.5M Hydrochloric acid bottle over the Graduated Cylinder.

Type 50 in the Transfer bar.

Click on Pour.

Transfer 50 mL of Hydrochloric acid into the Graduated Cylinder.
Drag Weighing boat and place it on the Scale.

Click on TARE.


Drag Sodium hydroxide bottle over to Weighing Boat.

Type 1 in the Transfer amount input bar.

Click on Pour.

Weigh 1 gram of Sodium hydroxide using Weighing Boat.


Transfer Sodium hydroxide from Weighing Boat to Foam Cup.

Click on the Graduated Cylinder.

Highlight the temperature.


T1 = 25 o C


Drag the Graduated Cylinder over Foam Cup.

Type 50 in the Transfer bar.

Click on Pour.

Click on the Graduated Cylinder, record its temperature.


Pour the contents of the Graduated Cylinder into the Foam Cup.

Click on the Foam Cup.

Highlight the temperature.

T2 = 36.96 o C

Click on the Foam Cup.


Record the highest temperature on the thermometer.


Thermometer shows 36.96 o C.

Slide Number 11

Calculation of heat of reaction for Rx2


q = m * s * ∆T.


∆T = (T1- T2) = (25 - 36.96) = -11.96.


q = (50+1) * 4.2 * -11.96


q = -2561.83 Joules


q = -2561.83 /1000=-2.561 KJ

ΔH2 = -2.561/0.025 = -102.47 KJ mol-1

Calculation of Molar Heat energy (delta H) in KJ/mol is given here.

delta H for reaction 2(Rx2) is -102.47 KJ mol-1

Select Foam Cup and Graduated Cylinder, scale and 0.5M HCl and press delete Delete the used apparatus and chemicals from the Workbench.
Double-click on Glassware icon.

Double-click on 25 mL Graduated Cylinder and a Foam Cup.


Right click on 25mL Graduated Cylinder.

Select the Duplicate option.


From Glassware menu take a new 25 mL Graduated Cylinder and a Foam Cup

We need two Graduated Cylinders.


Use Duplicate option in the context menu to make two copies.

Drag both the the cylinders. Drag both the cylinders to a convenient place on the Workbench.
Right click on the Cylinder.

Use context menu to rename the cylinder as A and B .

Label the cylinders as A and B.
On Chemical Stockroom;

Double-click on Strong-acids cabinet.

Double-click on 1.0 M HCl.


Double-click on Strong-bases cabinet.

Double-click on 1.0 M NaOH.

From the Chemical Stockroom click on Strong-acids cabinet.


Double click on 1.0 M Hydrochloric acid.

Close the cabinet.


From the Strong-bases cabinet, double click on 1.0 M Sodium hydroxide.

Close the cabinet.

Place 1 M HCl over the Graduated Cylinder.

Type 25 in the Transfer bar.

Click on Pour.


Click on the Graduated Cylinder.

Drag the Graduated Cylinder to the Foam Cup.

Type 25 in the Transfer bar.

Click on Pour.


Click on the Graduated Cylinder.

Highlight the temperature.

T1= 25o C

Transfer 25 mL of Hydrochloric acid(HCl) into graduated cylinder A.

Pour the Hydrochloric acid(HCl) from graduated cylinder to Foam Cup.


Note the temperature on the thermometer.

Place 0.1 M NaOH over the Graduated Cylinder.

Type 25 in the transfer bar.

Click on Pour.

Measure 25 mL of Sodium hydroxide in Graduated Cylinder B.
Click on the Graduated Cylindero

Drag the Graduated Cylinder to the Foam Cup.

Type 25 in the Transfer bar.

Click on Pour.

Pour the measured Sodium hydroxide into the Foam Cup.
Click on the Foam Cup.

Highlight the temperature


T2 = 31.67 o C

Click on Foam Cup.

Allow the reaction to take place for a few seconds.

Record the highest temperature.


Thermometer shows 31.67 o C.

Slide Number 12

Calculation of heat of reaction for Rx3

q = m * s * ∆T


∆T = (T1- T2) = (25 – 31.67) = -6.67


q =(25+25) * 4.2 * (-6.67)


q= -1400.7 Joules


q = -1400.7 /1000 = -1.400 KJ

ΔH3 =-1.400/0.025 = -56.03 KJ mol-1

Calculation of Molar Heat energy for reaction three is given here.


delta H for reaction 3( Rx3) is -56.03 KJ mol-1

Slide Number 13

Analysis of Results


This experiment is an example for Hess's law.


ΔH1 + ΔH3 = ΔH2


ΔH1 + ΔH3= (-45.32 KJ mol-1 + -56.03 KJ mol-1 ) = -101.35 KJ mol-1


ΔH2 = -102.47 KJ mol-1

Let us now analyze the results.


The value of Sum of heats of reactions for Rx1 and Rx3 is -101.35 KJ mol-1

Rx=reaction


The value of heat of reaction for Rx2 is -102.47 KJ mol-1


Therefore this experiment illustrates Hess's law.

Let us summarize.
Slide Number 14

Summary

In this tutorial we have,


Determined heat change for neutralization of Sodium hydroxide

and Hydrochloric acid.


Calculated heat of reaction for 3 different reactions.

Slide Number 15

Assignment


q = m * s * ∆T

q = (50+4) x 4.2 x (-21.18) = -4803.62 Joules

ΔH = -4803.62 /1000 = -4.803


ΔH = -4.803/0.1 = -48.03 KJ mol-1

For the assignment,

Explain why the reactions are exothermic.


Repeat Rx1 using 4 g of Sodium hydroxide and

calculate the heat of reaction.


Compare its value with the reaction in which 1 g of Sodium hydroxide was used.


Slide Number 16

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Slide Number 19

Acknowledgement

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