Home
Class 12
CHEMISTRY
A solution of 200 mL of 1 M KOH is added...

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?

A

`T_1 = T_2`

B

`T_2` twice as large as `T_1`

C

`T_1` is twice as large as `T_2`

D

`T_1` is four times as large as `T_2`

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to analyze the heat evolved during the neutralization reaction of KOH and HCl and how it affects the temperature rise in both scenarios. ### Step-by-Step Solution: 1. **Understanding the Reaction**: - KOH (potassium hydroxide) is a strong base, and HCl (hydrochloric acid) is a strong acid. When they react, they produce water and potassium chloride (KCl). - The reaction is: \[ \text{KOH} + \text{HCl} \rightarrow \text{KCl} + \text{H}_2\text{O} \] 2. **Heat Evolved in Neutralization**: - The heat evolved during the neutralization of 1 equivalent of a strong acid with a strong base is approximately 13.7 kcal (or 57.1 kJ). - Since both KOH and HCl are monobasic, 1 mole of KOH will neutralize 1 mole of HCl. 3. **Calculating Heat for 200 mL of 1 M Solutions**: - In the first case, we have 200 mL of 1 M KOH and 200 mL of 1 M HCl. - The total volume is 400 mL, and since both solutions are 1 M, we have 0.2 moles of KOH and 0.2 moles of HCl. - The heat evolved (q1) can be calculated as: \[ q_1 = 13.7 \text{ kcal} \times \frac{0.2 \text{ moles}}{1 \text{ mole}} = 13.7 \times 0.2 = 2.74 \text{ kcal} \] 4. **Calculating Heat for 100 mL of 1 M Solutions**: - In the second case, we have 100 mL of 1 M KOH and 100 mL of 1 M HCl. - The total volume is 200 mL, and we have 0.1 moles of KOH and 0.1 moles of HCl. - The heat evolved (q2) can be calculated as: \[ q_2 = 13.7 \text{ kcal} \times \frac{0.1 \text{ moles}}{1 \text{ mole}} = 13.7 \times 0.1 = 1.37 \text{ kcal} \] 5. **Relating Heat to Temperature Rise**: - The temperature rise (T) can be calculated using the formula: \[ q = m \cdot s \cdot \Delta T \] - Where: - \( q \) = heat evolved - \( m \) = mass of the solution (assuming density of water, 1 g/mL, for simplicity) - \( s \) = specific heat capacity (approximately 1 cal/g°C for water) - \( \Delta T \) = temperature rise 6. **Calculating Temperature Rise for Each Case**: - For the first case (200 mL + 200 mL): \[ 2.74 \text{ kcal} = 400 \text{ g} \cdot 1 \text{ cal/g°C} \cdot T_1 \] \[ T_1 = \frac{2.74 \times 1000 \text{ cal}}{400 \text{ g}} = 6.85 \text{ °C} \] - For the second case (100 mL + 100 mL): \[ 1.37 \text{ kcal} = 200 \text{ g} \cdot 1 \text{ cal/g°C} \cdot T_2 \] \[ T_2 = \frac{1.37 \times 1000 \text{ cal}}{200 \text{ g}} = 6.85 \text{ °C} \] 7. **Conclusion**: - Since both temperature rises \( T_1 \) and \( T_2 \) are equal, we conclude that: \[ T_1 = T_2 \] ### Final Answer: The correct conclusion is that \( T_1 = T_2 \).
Promotional Banner

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

100 ml of 1M NaOH is mixed with 50ml of 1N KOH solution. Normality of mixture is

100 mL of 0.15 M HCl is mixed with 100 mL of 0.005M HCl , what is the pH of the following solution approxmately

100ml of 0.2 M H_(2)SO_(4) is added to 100 ml of 0.2 M NaOH . The resulting solution will be

What is the pH of solution in which 25.0 mL of 0.1 M NaOH is added to 25 mL of 0.08 M HCl and final solution is diluted to 500 mL?

200 ml of water is added of 500 ml of 0.2 M solution. What is the molarity of this diluted solution?

10mL of 2(M) NaOH solution is added to 200mL of 0.5 (M) of NaOH solution. What is the final concentration?

1 mL of 0.1 N HCl is added to 999 mL solution of NaCl. The pH of the resulting solution will be :

If 100 mL of 1 N H_(2)SO_(4) is mixed with 100 mL of 1 M NaOH solution. The resulting solution will be

100 ml of 0.1 M HCl and 100 ml of 0.1 M HOCN are mixed then (K_a= 1.2 xx 10^(-6))