Answer:
Cu + 4HNO3 ---> Cu(NO3)2 + 2NO2 + 2H2O.
Explanation:
Balancing:
Cu + 4HNO3 ---> Cu(NO3)2 + 2 NO2 + 2H2O.
Answer: ΔH for the reaction is -277.4 kJ
Explanation:
The balanced chemical reaction is,
The expression for enthalpy change is,
![\Delta H=\sum [n\times \Delta H(products)]-\sum [n\times \Delta H(reactant)]](https://tex.z-dn.net/?f=%5CDelta%20H%3D%5Csum%20%5Bn%5Ctimes%20%5CDelta%20H%28products%29%5D-%5Csum%20%5Bn%5Ctimes%20%5CDelta%20H%28reactant%29%5D)
![\Delta H=[(n_{CCl_4}\times \Delta H_{CCl_4})+(n_{HCl}\times B.E_{HCl}) ]-[(n_{CH_4}\times \Delta H_{CH_4})+n_{Cl_2}\times \Delta H_{Cl_2}]](https://tex.z-dn.net/?f=%5CDelta%20H%3D%5B%28n_%7BCCl_4%7D%5Ctimes%20%5CDelta%20H_%7BCCl_4%7D%29%2B%28n_%7BHCl%7D%5Ctimes%20B.E_%7BHCl%7D%29%20%5D-%5B%28n_%7BCH_4%7D%5Ctimes%20%5CDelta%20H_%7BCH_4%7D%29%2Bn_%7BCl_2%7D%5Ctimes%20%5CDelta%20H_%7BCl_2%7D%5D)
where,
n = number of moles
Now put all the given values in this expression, we get
![\Delta H=[(1\times -139)+(1\times -92.31) ]-[(1\times -74.87)+(1\times 121.0]](https://tex.z-dn.net/?f=%5CDelta%20H%3D%5B%281%5Ctimes%20-139%29%2B%281%5Ctimes%20-92.31%29%20%5D-%5B%281%5Ctimes%20-74.87%29%2B%281%5Ctimes%20121.0%5D)
Therefore, the enthalpy change for this reaction is, -277.4 kJ
Explanation:
A process in which water vapor changes into liquid state is known as condensation. As we know that when energy is released in a reaction then it is known as exothermic reaction and when energy is absorbed in a reaction then it is known as endothermic reaction.
As vapors have high energy so, when they change into liquid state then heat energy is released by them. Therefore, condensation is an exothermic reaction.
As per Le Chatelier's principle, any disturbance caused in an equilibrium reaction will tend to shift the equilibrium in a direction away from the disturbance.
So, when there will occur a decrease in temperature then molecules of a gas will come closer to each other. Hence, there will also occur a decrease in vapor pressure of the gas.
Question:
The options are;
a. Temperature
b. Thermal Energy
c. Hotness
d. Fire Energy
Answer:
The correct option is;
b. Thermal energy
Explanation:
A burner on a stove produces thermal energy which is used to raise the temperature of the metal container (kettle, pot or pans) in which items are placed for heating.
Thermal energy is the internal energy of the system given off as heat which when transferred from one body to another causes the temperature of the receiving body to rise. Thermal energy in a burner is given off when the gaseous fuel reacts or burns in the presence of or with oxygen to produce carbon dioxide and water vapor in an exothermic reaction.
4C + 5H₂ + 13/2O₂ (-125 kJ) → C₄H₁₀ + O₂ → CO₂ + H₂O (-2877 kJ).
Answer:
A Walk in the City
Make a list of the number of cars, jeeps, tricycle, and even trucks you've seen on your way to school. On a Decision Making Chart, answer the question, "Does the volume of traffic affect the air quality in my local community?" Write your reasons for saying YES on the Reasons for column, and the reasons for saying NO on the Reasons Against column. At the bottom of a chart, make a position by writing your decision on the same question.
Decision Making Chart
[question]
[reason for]
[reason against]
[my decision]
