Reasons for Replacing Mercury with Water in Manometers

Why is Mercury often replaced by water in a Manometer (Select all that apply). Select all that apply.

A. Water is much less expensive that Mercury B. Water is much lighter than mercury C. Water is much more accurate that Mercury D. Water is safer than Mercury

The correct options for why Mercury is often replaced by water in a manometer are:

A. Water is much less expensive than Mercury
D. Water is safer than Mercury

Explanation:

• A. Water is much less expensive than Mercury: Water is readily available and inexpensive compared to mercury, which is a toxic heavy metal.
• D. Water is safer than Mercury: Mercury is hazardous to health and the environment, while water is non-toxic and safe to handle.

Note on the other options:

• B. Water is much lighter than mercury: This is not a reason for replacement; in fact, mercury is denser than water, which is why it is often used in manometers for measuring pressure.
• C. Water is much more accurate than Mercury: This is not accurate; mercury's high density allows for more precise measurements in certain applications, although water can be used in less precise applications.