Question

A certain metal is present in the soil, plants, bones, egg shells, sea shells and coral. It is also used to remove oxygen from molten steel and its hydroxide is used to detect \(\mathrm{CO}_{2}\). The metal is (1) \(\mathrm{Mg}\) (2) \(\Lambda 1\) (3) \(\mathrm{Ca}\) (4) \(\mathrm{Na}\)

Short answer

The metal is Calcium (\(\text{Ca}\)).

Step-by-step solution

Identify Clues from the Use Cases

List the various uses and occurrences of the metal mentioned: present in soil, plants, bones, egg shells, sea shells, coral, used to remove oxygen from molten steel, and its hydroxide detects \(\text{CO}_{2}\).

Consider Biological Presence

Metals commonly found in biological materials like bones and egg shells provide a clue. \(\text{Ca}\) (Calcium) is well-known for its role in bones, egg shells, and sea shells.

Review Function in Steel Manufacturing

Determine which metal is used to remove oxygen from molten steel. Calcium is known to serve this purpose in steel manufacturing.

Hydroxide to Detect \(\text{CO}_{2}\)

Check the use of the metal's hydroxide in chemistry. Calcium hydroxide (\(\text{Ca(OH)}_{2}\)) is used in limewater, which detects \(\text{CO}_{2}\) by forming calcium carbonate (\(\text{CaCO}_{3}\)).

Match All Conditions

Verify that \(\text{Ca}\) (Calcium) satisfies all given conditions: biological presence, steel manufacturing, and chemical detection of \(\text{CO}_{2}\). Therefore, the metal is Calcium (\(\text{Ca}\)).

Key concepts

Metal in Biological Materials

Calcium (Ca) is an essential metal in many biological materials. This means it is found in living organisms and plays critical roles in their functions and structures.

Calcium is present in bones, plant tissues, egg shells, sea shells, and coral, which are all biological materials.

Some key facts about calcium in biological systems:

• In bones, calcium is the primary component of hydroxyapatite, which gives bones their hardness and structure.
• Egg shells are predominantly made up of calcium carbonate (CaCO3), providing strength and protection to the developing embryo.
• Calcium ions (Ca^2^+) are crucial in plant metabolism and are involved in cell wall stabilization and signal transduction.
• In marine organisms like sea shells and coral, calcium is a major component, crucial for growth and development.

Understanding calcium's role in biology explains why it is ubiquitous in these materials and vital for life.

Oxygen Removal in Steel Manufacturing

Calcium also has industrial uses, particularly in steel manufacturing. It is used to remove oxygen impurities. Oxygen can cause brittleness and other undesirable properties in steel.

Here's how it works:

• Calcium acts as a deoxidizer when added to molten steel.
• It reacts with oxygen present in the molten steel to form calcium oxide (CaO).
• The calcium oxide then rises to the surface, where it can be removed, leaving behind purer steel.

This process improves the quality of the steel by making it more ductile and reducing the likelihood of defects. This use of calcium is crucial for producing high-strength, high-quality steel for construction, automotive, and other vital industries.

Calcium Hydroxide and CO2 Detection

Calcium hydroxide (Ca(OH)2), commonly known as slaked lime or limewater, has a unique property that makes it useful in detecting carbon dioxide (CO2).

When CO2 is passed through limewater, a chemical reaction occurs:

• The CO2 reacts with calcium hydroxide to form calcium carbonate (CaCO3) and water.
• This reaction produces a white precipitate of calcium carbonate, which clouds the limewater, indicating the presence of CO2.

The chemical equation for this reaction is:
Ca(OH)_{2(aq)} + CO_{2(g)} → CaCO_{3(s)} + H_{2}O_{(l)}

This reaction is used in laboratories and various industries to test for CO2.

Overall, Calcium hydroxide's ability to detect CO2 showcases its importance beyond biological and industrial uses, serving as a fundamental chemical in analytical techniques.