Question

Which of the following ore contains both calcium and magnesium? (a) Lime stone (b) Dolomite (c) Epsom salt (d) Carnallite

Short answer

(b) Dolomite contains both calcium and magnesium.

Step-by-step solution

Understand Mineral Composition

First, we need to identify the composition of the minerals listed. Limestone primarily contains calcium carbonate (CaCO₃). Dolomite is mainly composed of calcium magnesium carbonate (CaMg(CO₃)₂). Epsom salt is magnesium sulfate (MgSO₄) and contains no calcium. Carnallite is primarily a mixture of potassium and magnesium chlorides (KMgCl₃·6H₂O) and contains no calcium.

Identify Minerals with Both Calcium and Magnesium

Among the minerals listed in the options, Dolomite is the one that contains both calcium and magnesium. Its chemical formula, CaMg(CO₃)₂, clearly shows that it includes both elements in its structure, unlike the other options.

Conclude the Correct Answer

Given the compositions, Dolomite is the only option containing both calcium and magnesium. Therefore, Dolomite is the mineral that fits the criteria set by the problem.

Key concepts

Calcium Compounds

Calcium compounds are an essential group of inorganic compounds containing calcium, a soft gray alkaline earth metal. These compounds are ubiquitous in both the natural world and various industrial applications. The most common form of calcium encountered by many people is calcium carbonate

• A key component of limestone, marble, and chalk.
• Calcium carbonate is also widely used as a building material, and as a key ingredient in cement and concrete.
• Other calcium compounds include calcium oxide, also known as quicklime, and calcium hydroxide, or slaked lime.

Calcium is known for its role in biological systems. It is vital for bone health, enabling cells to grow, divide, and perform properly. Calcium compounds are often colorless or white as powder, and they exhibit specific reactions when in the presence of acids, resulting in the release of carbon dioxide gas. This property makes them useful in applications where gas evolution is needed.

Magnesium Compounds

Magnesium compounds encompass a wide range of substances distinguished by the presence of the element magnesium. Magnesium is a shiny gray metal, and when it forms compounds, it often contributes significant utility both in nature and industry.

• One of the most well-known magnesium compounds is magnesium sulfate, commonly known as Epsom salt.
• This compound is used for various purposes, including as a drying agent and in bath salts for a soothing effect on muscles.
• Another important magnesium compound is magnesium oxide, used extensively for its refractory properties in furnaces and kilns.

Magnesium plays a critical role in biology, being an essential ion in numerous biochemical reactions, including those involved in the production of cellular energy and protein synthesis. Similar to calcium compounds, magnesium compounds often appear white or colorless and can have a slightly bitter taste. They are crucial for industries requiring lightweight corrosion-resistant materials.

Chemical Composition Analysis

Chemical composition analysis is a fundamental process used in determining the elemental make-up of materials. This analysis allows us to understand what elements are present in a compound and their respective quantities. Various methods are employed to achieve this analysis, including:

• Spectroscopy techniques like X-ray fluorescence (XRF) and atomic absorption spectroscopy (AAS).
• These methods involve exciting atoms in a sample and measuring the energy or light they either absorb or emit.
• Another common approach is titration, which involves the incremental addition of a reagent to react with the sample until complete reaction is observed.

Through such analyses, it's possible to determine things like mineral composition and purity, which is invaluable in fields like geology, chemistry, and materials science. Understanding the chemical composition helps in quality control, research, and development of new materials. For students, mastering this skill supports the ability to discern specific characteristics of compounds such as dolomite, which contains both calcium and magnesium.