Home
Class 11
CHEMISTRY
A solution of 500mL of 2M KOH is added t...

A solution of `500mL` of `2M KOH` is added to `500mL` of `2M HCl` and the mixture is well shaken. The rise in temperature `T_(1)` is noted. The experiment is then repeated using `250mL` of each solution and rise in temperature `T_(2)` is againg noted. Assume all heat is taken up by the solution `:`

A

`T_(1)=T_(2)`

B

`T_(1)` is 2 times as larger as `T_(2)`

C

`T_(2)` is twice larger as `T_(1)`

D

`T_(1)` is 4 time as larger as `T_(2)`

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to analyze the heat of neutralization that occurs when KOH is mixed with HCl. ### Step-by-Step Solution: 1. **Identify the Reaction**: The neutralization reaction between KOH (potassium hydroxide) and HCl (hydrochloric acid) can be represented as: \[ \text{KOH} + \text{HCl} \rightarrow \text{KCl} + \text{H}_2\text{O} \] This reaction releases heat, which causes the temperature of the solution to rise. 2. **Calculate Moles of Reactants**: For the first scenario: - Volume of KOH = 500 mL = 0.5 L - Molarity of KOH = 2 M - Moles of KOH = Molarity × Volume = \(2 \, \text{mol/L} \times 0.5 \, \text{L} = 1 \, \text{mol}\) Similarly, for HCl: - Volume of HCl = 500 mL = 0.5 L - Molarity of HCl = 2 M - Moles of HCl = \(2 \, \text{mol/L} \times 0.5 \, \text{L} = 1 \, \text{mol}\) Thus, in the first scenario, we have 1 mole of KOH reacting with 1 mole of HCl. 3. **Heat of Neutralization**: The heat released during the neutralization is constant for strong acids and bases and can be denoted as \( \Delta H_{neut} \). For simplicity, we can assume it to be a constant value. 4. **Calculate the Temperature Rise (T1)**: The total heat released (\( q \)) can be expressed as: \[ q = n \cdot \Delta H_{neut} \] where \( n \) is the number of moles of the limiting reactant (which is 1 mole in this case). The heat absorbed by the solution will cause a rise in temperature \( T_1 \): \[ q = m \cdot c \cdot T_1 \] where: - \( m \) = mass of the solution (assuming density = 1 g/mL, for 1000 mL, mass = 1000 g) - \( c \) = specific heat capacity of water (approximately 4.18 J/g°C) Thus, we can equate the two expressions for heat: \[ n \cdot \Delta H_{neut} = m \cdot c \cdot T_1 \] 5. **Repeat with Half Volume**: In the second scenario, we have: - Volume of KOH = 250 mL = 0.25 L - Molarity of KOH = 2 M - Moles of KOH = \(2 \, \text{mol/L} \times 0.25 \, \text{L} = 0.5 \, \text{mol}\) Similarly for HCl: - Volume of HCl = 250 mL = 0.25 L - Molarity of HCl = 2 M - Moles of HCl = \(2 \, \text{mol/L} \times 0.25 \, \text{L} = 0.5 \, \text{mol}\) Again, we have 0.5 moles of KOH reacting with 0.5 moles of HCl. 6. **Calculate the Temperature Rise (T2)**: The heat released in this case will be: \[ q = 0.5 \cdot \Delta H_{neut} \] The mass of the solution will be 500 g (250 mL of solution, assuming density = 1 g/mL). The equation for heat absorbed becomes: \[ 0.5 \cdot \Delta H_{neut} = 500 \cdot c \cdot T_2 \] 7. **Relate T1 and T2**: From the equations derived: \[ 1 \cdot \Delta H_{neut} = 1000 \cdot c \cdot T_1 \] \[ 0.5 \cdot \Delta H_{neut} = 500 \cdot c \cdot T_2 \] Dividing the first equation by the second gives: \[ \frac{1 \cdot \Delta H_{neut}}{0.5 \cdot \Delta H_{neut}} = \frac{1000 \cdot c \cdot T_1}{500 \cdot c \cdot T_2} \] Simplifying this leads to: \[ 2 = 2 \cdot \frac{T_1}{T_2} \] Hence, we find that: \[ T_1 = T_2 \] ### Final Answer: The relationship between the temperature rises is: \[ T_1 = T_2 \]

To solve the problem, we need to analyze the heat of neutralization that occurs when KOH is mixed with HCl. ### Step-by-Step Solution: 1. **Identify the Reaction**: The neutralization reaction between KOH (potassium hydroxide) and HCl (hydrochloric acid) can be represented as: \[ \text{KOH} + \text{HCl} \rightarrow \text{KCl} + \text{H}_2\text{O} ...
Promotional Banner

Topper's Solved these Questions

  • THERMOCHEMISTRY

    P BAHADUR|Exercise Exercise 3B objective problems|18 Videos
  • THERMOCHEMISTRY

    P BAHADUR|Exercise Exercise 4 objective Problems|21 Videos
  • THERMOCHEMISTRY

    P BAHADUR|Exercise Exercise 27|1 Videos
  • REDOX REACTIONS

    P BAHADUR|Exercise Exercise(8) Statement:Explanation type problems|19 Videos
  • THERMODYNAMICS

    P BAHADUR|Exercise Exercise|232 Videos

Similar Questions

Explore conceptually related problems

A solution is 500 ml of 2M KOH is added to 500 ml of 2 M HCl and the mixture is well shaken. The rise in temperature T_(1) is noted. The experiment is then repeated using 250 ml of each solution and rise in temperature T_(2) is again noted. Assume all heat is taken by the solution

A solution of 200 mL of 1 M KOH is added to 200 mL of 1 M HCl and the mixture is well shaken. The rise in temperature T_(1) is noted. The experiment is repeated by using 100 mL of each solution and increase in temperature T_(2) is again noted. Which of the following is correct?

When 100 ml of 0.2 M HCl is mixed with 100 ml of 0.2 M NaOH , the rise in temperature is T_(1) . When the experiment is repeated using 200 ml each of the same solutions, the rise in temperature is T_(2) . Then

When 20 ml of 0.1 M HCl is mixed with 20 ml of 0.1 M NaOH , the rise in temperature is T_(1) . When the experiment is repeated using 20 ml of 0.2 M HCl and 0.2 M NaOH solutions, the rise in temperature is T_(2) . Then

P BAHADUR-THERMOCHEMISTRY-Exercise 3a objective problems
  1. A person requires 2870kcal of energy to lead normal daily life. If hea...

    Text Solution

    |

  2. If, combustion of 4g of CH(4) liberates 2.5kcal of heat, the heat of c...

    Text Solution

    |

  3. A solution of 500mL of 2M KOH is added to 500mL of 2M HCl and the mixt...

    Text Solution

    |

  4. Under the same conditions, how many mL of 1M KOH and 0.5M H(2)SO(4)sol...

    Text Solution

    |

  5. AB,A(2) and B(2) are diatomic molecules. If the bond enthalpies of A(2...

    Text Solution

    |

  6. DeltaC(p) for change ,N(2(g))+3H(2(g))=2NH(3(g)) is :

    Text Solution

    |

  7. Consider the reactions : C((s))+2H(2(g)) rarr CH(4(g)), DeltaH=-X kc...

    Text Solution

    |

  8. Which of the following is incorrect about the reaction : underset((D...

    Text Solution

    |

  9. For N(2)(g) + 3H(2)(g) rarr 2NH(3)(g) + 22kcal, E(a) for the reaction ...

    Text Solution

    |

  10. Bond energy of N-H,H-H and N-=N are a,b,c respectively. The DeltaH for...

    Text Solution

    |

  11. If heat of neutralisation is -13.7kcal at 25^(@)C and H(f(H(2)O))^(@)=...

    Text Solution

    |

  12. If (1)/(2)X(2)O((s)) rarr X((s))+(1)/(4)O(2(g)),DeltaH=90kJ then heat ...

    Text Solution

    |

  13. The data given below are for vapour phase reactions at constant pressu...

    Text Solution

    |

  14. The product of combustion of an aliphatic thiol (RSH) at 298K are :

    Text Solution

    |

  15. The bond energy of H(2) is 104.3 kcal mol^(-1) . If means that :

    Text Solution

    |

  16. Heat of neutralisation of NaOH and HCl is -57.46 kJ // equivalent. The...

    Text Solution

    |

  17. The lattice energy of solid NaCI is 180 kcal mol^(-1). The dissolution...

    Text Solution

    |

  18. Heat of neutralisation of HF is :

    Text Solution

    |

  19. The heat of atomisation of PH(3(g)) is 228kcal mol^(-1) and that of P(...

    Text Solution

    |

  20. Given that : 2CO((g))+O(2(g))rarr2CO(2(g)),DeltaH^(@)=-P kJ C((s))...

    Text Solution

    |