I got answer to this question.
The figures given in the parenthesis against each bond dissociation energies are Uncertainty.
e.g \(Al - Al 186 \pm 9kJ/mol\)
Search found 257 matches
- Fri Feb 05, 2021 6:30 am
- Forum: Chemistry forum
- Topic: Bond dissociation energies
- Replies: 2
- Views: 1502
- Fri Feb 05, 2021 5:59 am
- Forum: Chemistry forum
- Topic: Two step mole conversions
- Replies: 4
- Views: 2019
Re: Two step mole conversions
I am sorry. I computed for CH₃N₂. I shall edit my answer now.
Thanks for finding out error in the computation
Thanks for finding out error in the computation
- Fri Feb 05, 2021 5:19 am
- Forum: Chemistry forum
- Topic: Two step mole conversions
- Replies: 4
- Views: 2019
Re: Two step mole conversions
A sample of Calcium Nitride Ca3N2 having a mass 6.78 grams have 2.75e22 atoms which is= 0.0457 mole.
- Fri Feb 05, 2021 4:23 am
- Forum: Chemistry forum
- Topic: Hess's Law
- Replies: 5
- Views: 2186
Re: Hess's Law
I got detailed answer to this question given by chemistry professor as follows: (9) H_2SO_4 + 2H_2O \rightarrow H_2SO_4\cdot 2H_2O \Delta H= 116.7 kJ/mol Reverse(10)H_2SO_4\cdot2H_2O \rightarrow H_2SO_4\cdot H_2O + H_2O \Delta H =-38.56 kJ/mol Change sign Adding these two reactions to obtain... H_2S...
- Fri Feb 05, 2021 2:49 am
- Forum: Chemistry forum
- Topic: How to identify all these 4 unknown reactions?🤔
- Replies: 0
- Views: 12766
How to identify all these 4 unknown reactions?🤔
How to identify all these 4 unknown reactions?
- Fri Feb 05, 2021 12:26 am
- Forum: Chemistry forum
- Topic: Bond dissociation energies
- Replies: 2
- Views: 1502
Bond dissociation energies
What is the meaning of figures given in brackets in the attached page for bond dissociation energies?
- Tue Feb 02, 2021 5:08 am
- Forum: Chemistry forum
- Topic: Hess's Law
- Replies: 5
- Views: 2186
Re: Hess's Law
So, we get 116.7 - 38.56 = 78.14. (Unit of energy is unknown).
How can we say confidently without any experiment that this aforesaid answer is correct?
How can we say confidently without any experiment that this aforesaid answer is correct?
- Mon Feb 01, 2021 11:35 pm
- Forum: Chemistry forum
- Topic: Hess's Law
- Replies: 5
- Views: 2186
Hess's Law
Germain Henri Hess reported calorimetric analyses of a number of reactions of sulfuric acid and several of its hydrates. Among them were (9) H_2SO_4 + 2 H_2O \rightarrow H_2SO_4.2H_2O (10) H_2SO_4.H_2O + H_2O \rightarrow H_2SO_4.2H_2O (The numbering is from Hess's paper.) He reported that the heat e...
- Sat Jan 30, 2021 10:33 am
- Forum: Chemistry forum
- Topic: Computing pH of 1 L solution containing acetic acid and Sodium acetate after adding HCl.
- Replies: 3
- Views: 1567
Re: Computing pH of 1 L solution containing acetic acid and Sodium acetate after adding HCl.
Hello,
Consider the volume of HCl is negligible. Would you show me your computations of pH in the both cases, if possible?
Consider the volume of HCl is negligible. Would you show me your computations of pH in the both cases, if possible?
- Sat Jan 30, 2021 9:55 am
- Forum: Chemistry forum
- Topic: Computing pH of 1 L solution containing acetic acid and Sodium acetate after adding HCl.
- Replies: 3
- Views: 1567
Computing pH of 1 L solution containing acetic acid and Sodium acetate after adding HCl.
A 1.0 L solution contains 0.2 M CH3COOH and 0.2 M CH3COONa. What is the pH after 0.05 M of HCl has been added to the solution? What the effect would be on adding the HCl to 1 L containing 0.2 mol of CH3COOH alone (not a buffer)? In other words, What is the pH of 1 L solution containing 0.2 M of CH3C...
- Fri Jan 29, 2021 9:29 am
- Forum: Chemistry forum
- Topic: Why does water freeze in a pan of alcohol due to blowing air over it?
- Replies: 1
- Views: 1031
Why does water freeze in a pan of alcohol due to blowing air over it?
If you put a very shallow dish of water in a pan of alcohol and blow air over it by means of a electric fan, the water will freeze...why?
What is the answer?
What is the answer?
- Thu Jan 28, 2021 10:57 pm
- Forum: Chemistry forum
- Topic: Equilibrium test question
- Replies: 1
- Views: 1091
Equilibrium test question
Br_2(l) + H_2O (l) \rightleftharpoons Br^-(aq)+ BrO^- (aq) + 2H^+ If sodium hydroxide is added to the mixture, what will happen to the position of equilibrium? 1)The equilibrium shifts to the right. 2)The position of the equilibrium remains unchanged. 3)The equilibrium shifts to the left. Answer pr...
- Thu Jan 28, 2021 10:20 am
- Forum: Chemistry forum
- Topic: Computing percentage concentration of H2SO4
- Replies: 3
- Views: 1623
Re: Computing percentage concentration of H2SO4
How to compute specific gravity of 5.3 % w/w \(H_2SO_4 ? \) I know specific gravity =\(\frac{density_{substance}}{density_{water}}\)
Density of water=1.
Density of \(H_2SO_4=1.8302/cm^3\)
How to use specific gravity of 5.3% w/w \(H_2SO_4\) for computing volume of the solution?
Density of water=1.
Density of \(H_2SO_4=1.8302/cm^3\)
How to use specific gravity of 5.3% w/w \(H_2SO_4\) for computing volume of the solution?
- Thu Jan 28, 2021 8:07 am
- Forum: Chemistry forum
- Topic: Computing percentage concentration of H2SO4
- Replies: 3
- Views: 1623
Computing percentage concentration of H2SO4
175.0 g pure H_2O was placed in a beaker and thereafter 9.80 g pure H_2SO_4 was added and stirred. What is the total volume of the solution and what is the percentage concentration of H_2SO_4 in the solution? My answer: 1.0 ml= 1.0 g H_2O Hence 175.0 g pure H_2O =175.0 ml H_2O 9.80 g H_2SO_4 =5.36 m...
- Wed Jan 27, 2021 9:43 am
- Forum: Chemistry forum
- Topic: Determining calorimeter constant
- Replies: 1
- Views: 1098
Determining calorimeter constant
https://www.chemteam.info/Thermochem/Video-calorimeter-constant-02.mp4 My answer to the problem in the above video: If the constant were zero, the final temperature of the water would be 45.0 °C. So the amount of heat used by the calorimeter to heat from 21.3 to 43.3 is: (50.0) (4.184) (1.7) = 355.6...