Tag: distinguish between black copper oxide and black manganese dioxide

Questions Related to distinguish between black copper oxide and black manganese dioxide

Copper oxide is a:

distinguish between black copper oxide and black manganese dioxide practical work chemistry

  1. weak acid

  2. weak base

  3. strong acid

  4. strong base

Show answer
Correct Option: B
Explanation:

Copper oxide acts as weak base because when dissolved in water it produce mild basic hydroxide$Cu(OH) _2$

The gases evolved on the reaction of manganese dioxide with $HCl$ is/are:

distinguish between black copper oxide and black manganese dioxide practical work chemistry

  1. $H _2$

  2. $Cl _2$

  3. both A and B

  4. none of these

Show answer
Correct Option: B
Explanation:

${ MnO } _{ 2 }+4HCl\rightleftharpoons { MnCl } _{ 2 }+2{ H } _{ 2 }O+{ Cl } _{ \left( g \right)  }\uparrow $

Which one is the correct option for the solubility of $CuCl _2$ in water?

distinguish between black copper oxide and black manganese dioxide practical work chemistry

  1. Sparingly soluble

  2. Completely soluble

  3. Insoluble

  4. Soluble at higher temperature

Show answer
Correct Option: B
Explanation:

$CuCl _2$ completely ionises in water hence it is completely soluble in water.

Number of moles of $HCl$ requied to test one mole of copper oxide is:

distinguish between black copper oxide and black manganese dioxide practical work chemistry

  1. $1$

  2. $2$

  3. $3$

  4. $4$

Show answer
Correct Option: B
Explanation:

$CUO+2HCl\rightarrow { CuCl } _{ 2 }+{ H } _{ 2 }O$

2 $HCl$ moles for one mole $CUO$.

Number of moles of $HCl$ requied to test one mole of manganese dioxide is:

distinguish between black copper oxide and black manganese dioxide practical work chemistry

  1. $2$

  2. $3$

  3. $4$

  4. $1$

Show answer
Correct Option: C
Explanation:

${ MnO } _{ 2 }+4HCl\rightleftharpoons { MnCl } _{ 2 }+{ Cl } _{ 2 }+2{ H } _{ 2 }O$

Clearly from equation, ${ MnO } _{ 2 }$ need $4HCl$

Number of gaseous products that manganese dioxide forms on reaction with $HCl$ is:

distinguish between black copper oxide and black manganese dioxide practical work chemistry

  1. $0$

  2. $1$

  3. $2$

  4. $3$

Show answer
Correct Option: B
Explanation:

Manganisedioxide forms one gaseous products i.e. chlorine when react with hydrochloric acid as:

$MnO _2 + 4HCl \rightarrow MnCl _2 + Cl _2 + 2H _2O$

Which of the following will produce a gas with bleaching property on reaction with hydrochloric acid?

distinguish between black copper oxide and black manganese dioxide practical work chemistry

  1. $CuO$

  2. $MnO _2$

  3. Both A and B

  4. None of these

Show answer
Correct Option: B
Explanation:

$4HCl(aq)+MnO _2(S)\longrightarrow MnCl _2+2H _2O+Cl _2$

$MnO _2$ on reaction with $HCl$ gets reduced to $MnCl _2$ and $HCl$ gets oxidised to $Cl _2$

The gases evolved on the reaction of copper oxide with $HCl$ is/are:

distinguish between black copper oxide and black manganese dioxide practical work chemistry

  1. $H _2$

  2. $Cl _2$

  3. both A and B

  4. none of these

Show answer
Correct Option: D
Explanation:

${ CUO } _{ \left( S \right)  }+{ HCl } _{ \left( aq \right)  }\rightleftharpoons { CuCl } _{ 2\left( S \right)  }+{ H } _{ 2 }O\left( l \right) $

zero gaseous products.

The reaction between copper oxide and hydrochloric acid is a:

distinguish between black copper oxide and black manganese dioxide practical work chemistry

  1. acid base reaction

  2. replacement reaction

  3. combustion reaction

  4. both $A$ and $B$

Show answer
Correct Option: D
Explanation:

The reaction copper oxide and hydrochloric acid is an acid-base reaction due to the hydrogen and oxygen found in the reactants, then forming water ($H _2O$). This is also a replacement reaction because the copper ($Cu$) is "swapping out" with the hydrogen ($H$) creating two different molecules.

A manganese dioxide battery is treated with conc. HCl, what are the products?

distinguish between black copper oxide and black manganese dioxide practical work chemistry

  1. $MnCl _2$

  2. $H _2O$

  3. $Cl _2$

  4. All of above

Show answer
Correct Option: D
Explanation:

$MnO _2 + 4 HCl \rightarrow MnCl _2 + Cl _2 + 2 H _2O$