Question

The temperature of \(5 \mathrm{~mL}\) of a strong acid increases by \(5^{\circ} \mathrm{C}\) when \(5 \mathrm{~mL}\) of a strong base is added to it. If \(10 \mathrm{~mL}\) of cach are mixed, temperature should increase by (1) \(5^{\circ} \mathrm{C}\) (2) \(10^{\circ} \mathrm{C}\) (3) \(15^{\circ} \mathrm{C}\) (4) cannot be known

Short answer

The temperature increase would be 10°C.

Step-by-step solution

- Understand the initial condition

When 5 mL of a strong acid is mixed with 5 mL of a strong base, the temperature increases by 5°C.

- Determine the energy change

The temperature rise is due to the exothermic neutralization reaction. Mixing 5 mL of acid and 5 mL of base releases a certain amount of energy, which increases the temperature by 5°C.

- Analyze the effect of increasing volume

If the volumes are doubled to 10 mL of acid and 10 mL of base, the amount of substance involved in the reaction is also doubled. This means twice as much energy will be released.

- Calculate the new temperature increase

Since twice the amount of energy results in twice the temperature increase, the temperature rise will be 10°C when 10 mL of acid is mixed with 10 mL of base.

- Conclusion

The temperature would increase by 10°C.

Key concepts

Exothermic Reaction

An exothermic reaction is a type of chemical reaction that releases energy in the form of heat. When a strong acid and a strong base mix, they undergo a neutralization reaction. This specific type of reaction is exothermic. This means that as the acid and base combine to form water and a salt, they release heat into the surroundings.
This release of energy is the reason why we observe a temperature change during the reaction.

• The neutralization process forms water (H₂O) and a salt.
• The reaction produces heat, making the solution warmer.
• This phenomenon is common in many neutralization reactions.

Understanding exothermic reactions is crucial for predicting temperature changes in chemical processes.

Energy Release

Energy release is a key aspect of exothermic reactions. In the scenario described, mixing 5 mL of a strong acid with 5 mL of a strong base results in a measurable energy release that raises the temperature by 5°C. This energy is from the chemical bonds that are formed and broken during the reaction.
Here are some important points about energy release in such reactions:

• Energy is released when new bonds form in the water and salt.
• The amount of energy released is proportional to the quantity of reactants.
• Doubling the volume of acid and base will approximately double the energy released because more molecules are participating in the reaction.

By recognizing this pattern, you can predict changes in temperature based on the quantities of reactants.

Temperature Change

Temperature change is a direct indicator of energy release in exothermic reactions. When you initially mix 5 mL of acid with 5 mL of base, the temperature increases by 5°C. This tells you that a specific amount of energy has been released to cause this temperature rise.
If you double the volumes of both the acid and the base to 10 mL each, the energy released is also doubled. This will lead to a temperature increase twice as large as the initial change. In simple terms:

• Mixing equal volumes of strong acid and base leads to a higher temperature if the volumes are increased.
• The energy released in the reaction is spread over the combined volume of the acid and base.
• If 5 mL + 5 mL gives a 5°C increase, then 10 mL + 10 mL will result in a 10°C increase.

Therefore, understanding the relationship between reactant volume and temperature change is critical for accurately predicting outcomes in exothermic reactions.