Question

Water is an extremely weak electrolyte and therefore cannot conduct electricity. Why are we often cautioned not to operate electrical appliances when our hands are wet?

Short answer

Water seen in our daily lives is not pure and contains ions that can dramatically increase its conductivity. Wet hands operating electrical appliances can therefore create a path for the electrical current, which can lead to electric shocks.

Step-by-step solution

- Understanding Electrolytes

Electrolytes are substances which, when in a solution, conduct electricity. On its own, pure water is a weak electrolyte because it ionizes very poorly, meaning that it has very few ions available to conduct electricity.

- Water as a Conductor

Although water on its own does not conduct electricity very well, if any ions are present, they can dramatically improve its conductivity. Tap and natural water are not pure; they contain various dissolved minerals and salts, which means that it has ions available to conduct electricity.

- Dangers of Water and Electricity

When hands are wet, they can provide a conduit for electrical current if they come into contact with an electrical source. This can result in electric shock due to the ability of the water (containing ions) on the hands to conduct electricity. Therefore, it's important not to operate electrical appliances when hands are wet, as not only can the water on the hands conduct the electricity, but it can also aid in creating a path for the electricity to the ground.

- Conclusion

The primary reason why the caution to not operate electrical appliances when hands are wet is widely suggested, is because water from our daily lives (i.e., tap water, or even water on wet skin) contains ions which can conduct electricity and can thus pose a risk of electrical shock if in contact with electrical appliances.