Home
Class 11
CHEMISTRY
statement-1: If water is heated of 50^(@...

statement-1: If water is heated of `50^(@)C` then pH will increase.
STATEMENT-2: `K_(w)` increases with increase in temperature.

A

If both the statements are TRUE and STATEMENT-2 is the correct explanation of STATEMENT-1

B

If both the statements are TRUE AND STATEMENT-2 is NOT the correct explanation of STATEMENT-1

C

If STATEMENT-1 is TRUE and STATEMETN-2 is FALSE

D

If STATEMENT-1 is FALSE and STATEMENT-2 is TRUE

Text Solution

AI Generated Solution

The correct Answer is:
To solve the given question, we will analyze both statements step by step. ### Step 1: Analyze Statement 1 **Statement 1:** If water is heated to 50°C, then pH will increase. - At room temperature (25°C), water dissociates into hydrogen ions (H⁺) and hydroxide ions (OH⁻). The equilibrium can be represented as: \[ H_2O \rightleftharpoons H^+ + OH^- \] - The pH of pure water at 25°C is 7, which corresponds to a concentration of \( [H^+] = 1 \times 10^{-7} \, \text{mol/L} \). - When the temperature increases, the dissociation of water also increases, leading to a higher concentration of both H⁺ and OH⁻ ions. ### Step 2: Effect of Temperature on pH - As the temperature increases, the dissociation constant \( K_w \) (the ionic product of water) increases. This means that the concentration of H⁺ ions increases. - Since pH is defined as: \[ \text{pH} = -\log[H^+] \] - If the concentration of H⁺ ions increases, the pH value will actually decrease, not increase. **Conclusion for Statement 1:** Therefore, Statement 1 is **false**. ### Step 3: Analyze Statement 2 **Statement 2:** \( K_w \) increases with an increase in temperature. - The dissociation of water is an endothermic process, which means that as the temperature increases, the equilibrium shifts to favor the formation of more H⁺ and OH⁻ ions. - Thus, the value of \( K_w \), which is defined as: \[ K_w = [H^+][OH^-] \] - will increase with temperature. **Conclusion for Statement 2:** Therefore, Statement 2 is **true**. ### Final Conclusion - Statement 1 is false, and Statement 2 is true. Hence, the correct answer is that Statement 1 is incorrect and Statement 2 is correct. ### Summary of Results - **Statement 1:** False - **Statement 2:** True
Promotional Banner

Similar Questions

Explore conceptually related problems

Resistance increases with increases in temperature for

pH of water ………… with increase in temperature.

STATEMENT-1: pH of water decreases with increase in temperature. STATEMENT-2 : K_(w) of water decreases with increase in temperature.

The solubility of NaCl in water decreases with increases in temperature.

With increases in temperature pH of pure water

STATEMENT-1 : As temperature of a conducting wire increases, the slope of V-I graph ( V on y - axis and I on x-axis ) increases. and STATEMENT-2 : For a conductor, the resistance increases with increase in temperature.

Assertion (A): pH of water increases with an increase in temperature. Reason (R) : K_(w) or water increases with increase in temperature.

STATEMENT-1 : The drift velocity of electrons in a metallic wire will decrease, if the temperature of the wire is increased. and STATEMENT-2 : On increasing the temperature of the wire , conductivity of metallic wire decreases.

The solubility of most substances in water increases with increase in temperature. True or false?

STATEMENT-1 : Resistance of a conductor increases on increasing temperature. STATEMENT-2 : Drift speed decreasees on increasing temperature. STATEMENT-3 : Relaxation time decreases on increasing temperature.