Question

Carbon electrodes are immersed in water and electric current is passed through it. Which of the following statements is correct?

• A. Oxygen bubbles will be formed at the electrode which is connected to the negative terminal of the battery.
• B. Hydrogen gas will be formed at the electrode which is connected to the positive terminal of the battery.
• C. No gas is formed at any electrode.
• D. Hydrogen gas will be formed at the electrode which is connected to the negative terminal of the battery.

Answer 1

The correct option is D Hydrogen gas will be formed at the electrode which is connected to the negative terminal of the battery.

When the carbon electrodes are immersed in water, and current is passed, bubbles of oxygen and hydrogen are produced. Oxygen bubbles are formed on the electrode connected to the positive terminal of the battery and hydrogen bubbles are formed on the electrode connected to the negative terminal of the battery.
$H^{+}$ ions move towards the electrode which is connected to the negative terminal of the battery, gain electrons and are released as $H_2$ gas.
$2H^{+}+2e^{-}\to H_2$