Tag: some important compounds of magnesium and calcium

Questions Related to some important compounds of magnesium and calcium

Super phosphate consist(s) of:

  1. calcium sulphate

  2. calcium hydrogen phosphate

  3. calcium carbonate

  4. both $A$ and $B$


Correct Option: D
Explanation:

Single superphosphate (SSP) was the first commercial mineral fertilizer, and it led to the development of the modern plant nutrient industry. This material was once the most commonly used fertilizer, but other phosphorus (P) fertilizers have largely replaced SSP because of its relatively low P content.

The general chemical reaction involved in the production of SSP is

${ Ca } _{ 3 }{ \left( P{ O } _{ 4 } \right)  } _{ 2 }+2{ H } _{ 2 }S{ O } _{ 4 }\longrightarrow Ca{ ({ H } _{ 2 }P{ O } _{ 4 }) } _{ 2 }+2CaS{ O } _{ 4 }$

Total how many hydrogen atoms are present in one molecule of triple superphosphate?

  1. 6

  2. 8

  3. 9

  4. 12


Correct Option: A
Explanation:

Monocalcium phosphate is an inorganic compound with the chemical formula $Ca{ ({ H } _{ 2 }P{ O } _{ 4 }) } _{ 2 }$. It is commonly found as the monohydrate $Ca{ ({ H } _{ 2 }P{ O } _{ 4 }) } _{ 2 }.{ H } _{ 2 }O$ Both salts are colourless solids. They are used mainly as superphosphate fertilizers.

So a total of 6 hydrogen atoms are present.

Reactants of superphosphate are mixed in a ____________ chamber with a mechanical stirrer and two valves at the bottom. 

  1. cast iron

  2. stainless steel

  3. mild stainless steel

  4. copper


Correct Option: A
Explanation:

A well powdered phosphate rock or bone ash mixed known quantity of concentrate sulphuric acid is introduced into a cast iron chamber provided with mechanical stirrer and two valves at bottom. Each valve opens in a big chamber called den. The mixture is stirred for 2 to 5 minutes and then  dumped mechanically into one of the dens through the valve. The mass is kept in the den for about 24 hours.

Valves of an iron chamber used in the manufacturing of superphosphate opens in a big chamber called _________.

  1. reactor

  2. vessel

  3. den

  4. control room


Correct Option: C
Explanation:

A well powdered phosphate rock or bone ash mixed known quantity of concentrate sulphuric acid is introduced into a cast iron chamber provided with mechanical stirrer and two valves at bottom. Each valve opens in a big chamber called den. The mixture is stirred for 2 to 5 minutes and then  dumped mechanically into one of the dens through the valve. The mass is kept in the den for about 24 hours.

Reactant of the superphosphate production are stirred for ___________ minutes and then into one of the dens through the valve.

  1. 5-10 mins

  2. 10-15 mins

  3. 2-5 mins

  4. 20-30 mins


Correct Option: C
Explanation:

A well powdered phosphate rock or bone ash mixed known quantity of concentrate sulphuric acid is introduced into a cast iron chamber provided with mechanical stirrer and two valves at bottom. Each valve opens in a big chamber called den. The mixture is stirred for 2 to 5 minutes and then  dumped mechanically into one of the dens through the valve. The mass is kept in the den for about 24 hours.

A mixture of single superphosphate and triple superphosphate is called:

  1. mean phosphate

  2. average phosphate

  3. double phosphate

  4. none of the above


Correct Option: C
Explanation:

A mixture of single superphosphate and triple superphosphate is called double superphosphate. More than 90% of a typical superphosphate fertilizer is water-soluble.

Hence option C is correct.

The balanced chemical reaction for the manufacturing of superphosphate is:

  1. $Ca _3(PO _4) _2 +\ 2H _2SO _4 +\ 4H _2O \ \longrightarrow Ca(H _2PO _4) _2 \ + \ 2CaSO _4.2H _2O $

  2. $Ca _3(PO _4) _2 +\ H _2SO _4 +\ 4H _2O \ \longrightarrow Ca(H _2PO _4) _2 \ + \ CaSO _4.2H _2O $

  3. $Ca _3(PO _4) _2 +\ 2H _2SO _4 +\ 2H _2O \ \longrightarrow 2Ca(H _2PO _4) _2 \ + \ CaSO _4.2H _2O $

  4. $Ca _3(PO _4) _2 +\ 4H _2SO _4 +\ 2H _2O \ \longrightarrow Ca(H _2PO _4) _2 \ + \ 2CaSO _4.2H _2O $


Correct Option: A
Explanation:

A well powdered phosphate rock or bone ash mixed known quantity of concentrate sulphuric acid is introduced into a cast iron chamber provided with mechanical stirrer and two valves at bottom. Each valve opens in a big chamber called den. The mixture is stirred for 2 to 5 minutes and then dumped mechanically into one of the dens through the valve. The mass is kept in the den for about 24 hours.

${ Ca } _{ 3 }{ \left( P{ O } _{ 4 } \right)  } _{ 2 }+2{ H } _{ 2 }S{ O } _{ 4 }+4{ H } _{ 2 }O\longrightarrow Ca{ ({ H } _{ 2 }P{ O } _{ 4 }) } _{ 2 }+2CaS{ O } _{ 4 }.2{ H } _{ 2 }O+Heat$

A mixture of calcium sulphate and calcium dihydrogen phosphate is obtained .This mixture is called superphosphate.

What is the chemical formula of triple superphosphate?

  1. $Ca(H _2PO _4).2H _2O$

  2. $Ca{(H _2PO _4)} _2.H _2O$

  3. $Ca(H _2PO _4).3H _2O$

  4. $CaSO _4.3H _2O$


Correct Option: B
Explanation:

Triple Superphosphate is manufactured in a two stage process. First, sulphuric acid is reacted with phosphate rock, to produce phosphoric acid. Gypsum is a by-product of the stage and is removed. Secondly, the phosphoric acid is reacted with phosphate rock resulting in triple superphosphate.
Calcium superphosphate is an inorganic compound with the chemical formula $Ca{ ({ H } _{ 2 }P{ O } _{ 4 }) } _{ 2 }$. It is commonly found as the monohydrate $Ca{ ({ H } _{ 2 }P{ O } _{ 4 }) } _{ 2 }.{ H } _{ 2 }O$ . Both salts are colourless solids. They are used mainly as superphosphate fertilizers.

What is the other name for calcium dihydrogen phosphate?

  1. Superphosphate

  2. Calcium phosphorite

  3. Monocalcium phosphate

  4. none of the above


Correct Option: C
Explanation:

Monocalcium phosphate is an inorganic compound with the chemical formula $Ca{ ({ H } _{ 2 }P{ O } _{ 4 }) } _{ 2 }$. It is commonly found as the monohydrate $Ca{ ({ H } _{ 2 }P{ O } _{ 4 }) } _{ 2 }.{ H } _{ 2 }O$ Both salts are colourless solids. They are used mainly as superphosphate fertilizers.

Calcium phosphate used in the manufacturing of superphosphate is available in which form?

  1. Powdered phosphate rock

  2. Bone ash

  3. Both $A$ and $B$

  4. Liquid


Correct Option: C
Explanation:

As a mineral resource, “phosphate rock” is defined as unprocessed ore and processed concentrates that contain some form of apatite, a group of calcium phosphate minerals that is the primary source for phosphorus in phosphate fertilizers, which are vital to agriculture.

Bone ash is a white material produced by the calcination of bones. Typical bone ash consists of about 55.82% calcium oxide, 42.39% phosphorus pentoxide, and 1.79% water. The exact composition of these compounds varies upon the type of bones being used, but generally the formula for bone ash is: ${ Ca } _{ 5 }(OH){ (P{ O } _{ 4 }) } _{ 3 }$.