Tag: water

Quizzes (60) Questions (60)

Questions Related to water

Multiple choice chemistry water drying and dehydrating agents hydrolysis of salts and the ph of their solutions chemical equilibrium and acids-bases

Chloride which is insoluble in water is :

  1. sodium chloride

  2. potassium chloride

  3. mercurous chloride

  4. calcium chloride
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Chloride salts include sodium chloride (common salt), potassium chloride, calcium chloride, and ammonium chloride. Most chloride salts are readily soluble in water, but mercurous chloride (calomel) and silver chloride are insoluble, and lead chloride is only slightly soluble.

Multiple choice chemistry water drying and dehydrating agents hydrolysis of salts and the ph of their solutions chemical equilibrium and acids-bases

Does $Mg(OH) _2$ react with sodium hydroxide?

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A universal indicator is a pH indicator composed of a solution of several compounds that exhibits smooth colour changes over a pH value range from 1-14 to indicate the acidity or alkalinity of solutions. Two basic hydroxides do not react with each other as these are bases but not alkali.

Multiple choice chemistry water drying and dehydrating agents hydrolysis of salts and the ph of their solutions chemical equilibrium and acids-bases

$NaCl + H _2SO _4\overset{\Delta}{\longrightarrow}HCl \ +$

  1. $NaHSO _4$
  2. $Na _2SO4$
  3. $Na _2SO _3$

  4. none of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Reacting sodium chloride and sulphuric acid at elevated temperature leads to production of sodium bisulphate and hydrogen chloride. Little amount of sodium sulphate is also formed which reacts with the sulphuric acid to yield sodium bisulphate or sodium hydrogen sulphate.
$NaCl\left( s \right) +{ H } _{ 2 }{ SO } _{ 4 }\rightarrow { NaHSO } _{ 4 }\left( s \right) +HCl$

Multiple choice chemistry water drying and dehydrating agents hydrolysis of salts and the ph of their solutions chemical equilibrium and acids-bases

Identify the correct representation of reaction occurring during chloro-alkali process. 

  1. $2NaCl(l)+ 2H _2O(l) \rightarrow 2NaOH(l) + Cl _2(g) + H _2(g)$
  2. $2NaCl(s)+ 2H _2O(aq) \rightarrow 2NaOH(aq) + Cl _2(g) + H _2(g)$
  3. $2NaCl(aq)+ 2H _2O(l) \rightarrow 2NaOH(aq) + Cl _2(aq) + H _2(aq)$
  4. $2NaCl(aq)+ 2H _2O(l) \rightarrow 2NaOH(aq) + Cl _2(g) + H _2(g)$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Chloro-alkali process is an industrial process for the electrolysis of sodium chloride. It is used to produce chlorine and sodium hydroxide. Aqueous sodium chloride or brine ina membrane cell.


At cathode: ${ 2H } _{ 2 }O+2{ e }^{ - }\rightarrow { H } _{ 2 }+{ 2OH }^{ - }$ 

At anode: $2{ Cl }^{ - }\rightarrow { Cl } _{ 2 }+2{ e }^{ - }$ 


$2NaCl(aq)+2{ H } _{ 2 }O\rightarrow { Cl } _{ 2 }(g)+{ H } _{ 2 }(g)+2NaOH(aq)$


Option $(D)$ suggests the correct reaction.

Multiple choice chemistry water drying and dehydrating agents hydrolysis of salts and the ph of their solutions chemical equilibrium and acids-bases

Addition of large quantity of Iron salt will coagulate blood.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Addition of large quantity of Iron salt will coagulate blood. A trivalent iron (ferric ions) generates hydroxyl radicals, which subsequently form soluble plasma fibrinogen (FBG) into an insoluble fibrin clot.
Multiple choice chemistry water drying and dehydrating agents hydrolysis of salts and the ph of their solutions chemical equilibrium and acids-bases

Which of the following salts when dissolved in water would give acidic solution(s)?

  1. $Na _2SO _4$
  2. $(NH _4) _2SO _4$
  3. $CH _3COONa$
  4. $KCI$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Ammonium sulfate reacts with water to form sulfuric acid which is highly acidic in nature as it completely dissociates to give hydrogen ions.

Multiple choice chemistry water drying and dehydrating agents hydrolysis of salts and the ph of their solutions chemical equilibrium and acids-bases

What are the products formed when an aqueous solution of magnesium bicarbonate is boiled?

  1. $MgCO _3,\, H _2O,\, CO _2$
  2. $Mg(HCO _3) _2,\, H _2O$
  3. $Mg(OH) _2,\, H _2O$
  4. $Mg,\, CO _2,\, H _2O$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

When magnesium bicarbonate is boiled $MgCO _3, H _2O$ and $CO _2$ are formed. A small amount of $Mg(OH) _2$ is also formed.

Reaction: $Mg(HCO _ 3) _2\xrightarrow[\Delta]{} MgCO _ 3+H _ 2O+CO _ 2+Mg(OH) _ 2$

Multiple choice chemistry water drying and dehydrating agents hydrolysis of salts and the ph of their solutions chemical equilibrium and acids-bases

Which of the following salts on heating gives a mixture of two gases?

  1. $Ba(NO _3) _2$
  2. $NaNO _3$
  3. $KNO _3$
  4. $RbNO _3$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

$(A)$  $Ba(NO _3) _2$


$Reason$ :  The elements in the group 2 includes beryllium($Be$), magnesium($Mg$), calcium($Ca$), strontium($Sr$), barium($Ba$) and radium($Ra$).
The group 2 nitrates, on heating, gives metal oxide, nitrogen dioxide and oxygen gas.
For example - $2Ba(NO _3) _2(s)$ $\rightarrow$ $2BaO(s)$ + $4NO _2(g)$ + $O _2(g)$
Group 2 nitrates also become more thermally stable down the group. 

Multiple choice chemistry water drying and dehydrating agents hydrolysis of salts and the ph of their solutions chemical equilibrium and acids-bases

When hydrated $MgCl _2.\, 6H _2O$ is strongly heated:

  1. $MgO$ is formed
  2. $Mg(OH) _2$ is formed
  3. $Mg(OH)Cl$ is formed
  4. Ahydrous $MgCl _2$ is formed
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Magnesium hydrochloride is hygroscopic in nature and it loses its water molecules with the formation of magnesium oxide. When mixed with hydrated magnesium oxide, magnesium chloride forms a hard material called Sorel cement.