Zinc: Essential Trace Metal Quiz

Questions and Answers

What is the primary use of zinc in industry?

As a dietary supplement for health improvement

As a primary material for electrical wiring

In the manufacturing of pharmaceuticals

Coating on iron and steel to prevent corrosion (correct)

Which statement accurately describes the role of zinc in human health?

It has no significant role in the immune system

It decreases appetite and promotes cell growth

It is primarily responsible for the absorption of carbohydrates

It boosts the immune system and aids in wound healing (correct)

What is the permissible level of zinc in water set by the WHO?

1 mg/L

10 mg/L

3 mg/L (correct)

5 mg/L

What type of titration method is used to determine zinc content quantitatively?

Complexometric direct titration with EDTA Signup and view all the answers

At what pH range does the Zn-indicator complex formation occur?

pH 7 to 11 Signup and view all the answers

What color does Eriochrome black T indicator change to when it is free?

Blue Signup and view all the answers

Why is zinc important for electric vehicles?

It can store energy more efficiently than other battery systems Signup and view all the answers

What occurs near the endpoint of a complexometric titration involving zinc?

The Zn-indicator complex breaks down, releasing free indicator Signup and view all the answers

Study Notes

General Facts about Zinc

Zinc is the second most common trace metal in the human body, after iron.
It is found naturally in the earth, air, and foods consumed.
Comprises approximately 0.004% of the Earth's crust.
Essential for health: boosts immune system, aids cell growth, regulates appetite, and promotes wound healing.

Biological Significance

Vital for the growth and development of nearly all forms of life.
An average healthy adult contains between 1.4 to 2.3 grams of zinc.
Plays a critical role in maintaining various physiological functions in the body.

Industrial Uses

Primarily used as a protective coating for iron and steel to prevent corrosion.
Zinc batteries can store twelve times more energy per kilogram than other battery systems, enhancing electric vehicle performance.
Zinc-air batteries have achieved speeds of up to 120 mph in cars.

Water Quality Standards

The World Health Organization (WHO) sets a permissible zinc level in drinking water at 3 mg/L.

Analytical Techniques

Zinc content can be quantitatively analyzed using complexometric direct titration with EDTA at pH 10.
Complexometric titration involves the formation of coordination complexes between metal ions and chelating agents.

Chelating Agents and Indicators

Most chelating agents are polyaminocarboxylic acids, with EDTA being a common example.
Eriochrome black T is used as an indicator in zinc titrations: it appears blue when free and wine-red when complexed with zinc.
At pH 7-11, zinc ions create a Zn-indicator complex that shows a wine color.
At the endpoint of the titration, EDTA displaces the indicator, resulting in a blue color indicating the completion of the reaction.

Description

Test your knowledge about zinc, an essential trace metal found in the earth, air, and food. This quiz covers its health benefits, prevalence in the human body, and importance for growth and development. Discover how zinc plays a critical role in your overall health.