Tag: some important compounds of magnesium and calcium

Questions Related to some important compounds of magnesium and calcium

Reaction of magnesium with air is:

some important compounds of magnesium and calcium the s-block elements chemistry

  1. endothermic reaction

  2. reversible reaction

  3. exothermic reaction

  4. substitution reaction

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Correct Option: C
Explanation:

Option $(C)$ is correct.

The reaction of magnesium with air is an exothermic reaction as magnesium burns with dazzling brilliance in the air forming white shiny magnesium oxide with the evolution of a lot of heat.
$2Mg + O _2 \rightarrow 2MgO + heat$

If magnesium is gently heated, it forms:

some important compounds of magnesium and calcium the s-block elements chemistry

  1. magnesium oxide

  2. magnesium sulfide

  3. magnesium nitrite

  4. magnesium carbonate

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Correct Option: A
Explanation:

Option $(A)$ is correct.

If magnesium is gently heated, it forms magnesium oxide with the release of a large amount of heat.
$2Mg + O _2 \rightarrow 2MgO + heat$

Oxide used to treat indigestion and relieve pain is:

some important compounds of magnesium and calcium the s-block elements chemistry

  1. magnesium oxide

  2. magnesium hydroxide

  3. potassium oxide

  4. both $A$ and $B$

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Correct Option: D
Explanation:

Option $(D)$ is correct.

Oxide used to treat indigestion and relieve pain are magnesium oxide and magnesium hydroxide.
They act as an antacid to relieve indigestion, sour stomach, and heartburn.

Color of solid magnesium is:

some important compounds of magnesium and calcium the s-block elements chemistry

  1. dark grey

  2. silvery grey

  3. black

  4. whitish silver

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Correct Option: B
Explanation:

Option $(B)$ is correct.

The colour of solid magnesium is silvery grey. It has a shiny lustre, also known as a glow. When it burns, magnesium creates a white light. 

Which of the following statement is correct?

some important compounds of magnesium and calcium the s-block elements chemistry

  1. Magnesium oxide is highly soluble in water

  2. Magnesium oxide is slightly solution in water

  3. Magnesium oxide is insoluble in water

  4. All alkaline earth metal oxides are insoluble in water

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Correct Option: B
Explanation:

Option $(B)$ is correct.

Magnesium oxide is slightly soluble in water.It is due to an intramolecular force of the magnesium oxide compound. In fact, magnesium oxide is very small, and the attraction forces are very strong to be broke apart when reacted with water.

Color of magnesium oxide is:

some important compounds of magnesium and calcium the s-block elements chemistry

  1. white

  2. blue

  3. grey

  4. pink

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Correct Option: A
Explanation:

Option $(A)$ is correct.

Color of magnesium oxide is white. It is hygroscopic solid mineral that occurs naturally as periclase and is a source of magnesium.

Calcining at different temperatures produces magnesium oxide of different reactivity.

some important compounds of magnesium and calcium the s-block elements chemistry

  1. True

  2. False

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Correct Option: A
Explanation:

Calcining at different temperatures produces magnesium oxide of different reactivity.

High temperatures (1500 – 2000 °C) diminish the available surface area and produces dead-burned (often called dead burnt) magnesia, an unreactive form used as a refractory.
Calcining temperatures (1000 – 1500 °C) produces hard-burned magnesia, which has limited reactivity and calcining at lower temperature, (700 – 1000 °C) produces light-burned magnesia, a reactive form, also known as caustic calcined magnesia.
Although some decomposition of the carbonate to oxide occurs at temperatures below 700 °C, the resulting material appears to reabsorb carbon dioxide from the air.

Which of the following alkali earth metal(s) form ionic oxide?

some important compounds of magnesium and calcium the s-block elements chemistry

  1. $BeO$

  2. $MgO$

  3. $CaO$

  4. $SrO$

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Correct Option: B,C,D
Explanation:

$BeO$ forms amphoteric oxide because it acts as both acidic oxide as well as basic oxide. $MgO,CaO,SrO$ are ionic oxide.

Which of the following is not a method of production of magnesium oxide?

some important compounds of magnesium and calcium the s-block elements chemistry

  1. $ Mg+O _2 \rightarrow MgO $

  2. $MgCO _3\xrightarrow{\Delta}MgO+CO _2$

  3. $Mg(OH) _2\xrightarrow{\Delta}MgO+H _2O$

  4. None of the above

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Correct Option: D
Explanation:

All of the above methods are used for the production of magnesium oxide.when magnesium is burnt in air magnesium oxide is produced. When magnesium carbonate is calcined magnesium oxide and carbon dioxide is produced. When magnesium hydroxide is calcined magnesium oxide and water is produced.

Magnesium oxide is not used in:

some important compounds of magnesium and calcium the s-block elements chemistry

  1. refractive industry

  2. medicine

  3. construction

  4. none of these

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Correct Option: D
Explanation:
Option $(D)$ is correct.
Magnesium oxide is a mineral supplement used to treat or prevent low levels of magnesium in the blood. Magnesium is important for many systems in the body, but it is especially vital for healthy muscles and bones. Some people use it as an antacid to relieve heartburn, sour stomach, or acid indigestion. It also may be used as a laxative for short-term, rapid emptying of the bowel. It  is available without a prescription.