Tag: chemistry

Questions Related to chemistry

What is an electrolyte?

chemistry electrolysis electrolytes and non-electrolytes introduction to electrolysis chemical reactions

  1. Electrolytes are substances that dissolve by separating into ions in solution.

  2. Electrolytes are substances that do not conduct electricity but dissolve in water.

  3. Electrolytes are substances that have covalent bonds.

  4. Electrolytes are substances that share electrons.

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Correct Option: A
Explanation:

Electrolyte is an substance that dissolve by separating into ions in solution . They even can conduct electricity. As their ions are free to carry current.

Two solutions of X and Y electrolytes are taken in two beakers and diluted by adding $500$ mL of water. $\Lambda _m$ of X increases by $1.5$ times while that of Y increases by $20$ times, what could be the electrolytes X and Y?

chemistry electrolysis electrolytes and non-electrolytes introduction to electrolysis chemical reactions

  1. $X\rightarrow NaCl, Y\rightarrow KCl$

  2. $X\rightarrow NaCl, Y\rightarrow CH _3COOH$

  3. $X\rightarrow KOH, Y\rightarrow NaOH$

  4. $X\rightarrow CH _3COOH, Y\rightarrow NaCl$

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Correct Option: B
Explanation:

On dilution, the molar conductivity of X increases by 1.5 times and Y by 20 times. Hence, X is a strong electrolyte and Y is a weak electrolyte.


Hence, option B is correct.

The substances whose aqueous solutions conduct electricity are called : 

chemistry electrolysis electrolytes and non-electrolytes introduction to electrolysis chemical reactions

  1. electrolytes

  2. non-electrolytes

  3. conductors

  4. metals

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Correct Option: A
Explanation:

The substances whose aqueous solutions conduct electricity are called electrolytes.

$Cr - C$ bond in the compound $[Cr(CO) _6]$ shows $\pi$ - character due to :

chemistry coordination chemistry bonding in metal carbonyls metal carbonyls coordination compounds

  1. covalent bonding

  2. coordinate bonding

  3. synergic bonding

  4. ionic bonding

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Correct Option: C
Explanation:
  1. Synergic bonding is the description of the bonding of $\pi$ - configuration ligands to the transition metal which involves donation of electrons through back bonding.
    2. Mainly carbonyl ligands in complex compounds involves in this type of bonding.

$\left[ {C{O _2}{{(CO)} _8}} \right]$ displays:

chemistry coordination chemistry bonding in metal carbonyls metal carbonyls coordination compounds

  1. One-Co Co bond, six terminal CO and two bridging CO

  2. One-Co Co bond, four terminal CO and four bridging CO

  3. No-Co Co bond, six terminal CO and two bridging CO

  4. No-Co Co bond, four terminal CO and four bridging CO

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Correct Option: C

Which of the following factors tends to increase the stability of metal ion complexes?

chemistry coordination chemistry bonding in metal carbonyls metal carbonyls coordination compounds

  1. Higher ionic radius of the metal ion

  2. Higher charge/size ratio of the metal ion

  3. Lower ionisation potential of the metal ion

  4. Lower basicity of the ligand

Show answer
Correct Option: B
Explanation:
For a given ligand, the stability of complexes of metallic ions having the same charge on them decreases with the increase of the size of the central metal ions. Again if the charge of central metal ion is more and the site is small, then the stability of the complex is more. Higher charge/size ratio of metal ion i.e highly charged cation and the smaller cation can form more stable complexes.
Answer will be B.

Consider the following complexes $[V(CO) _6]^-,[Cr(CO) _6]$ and $[Mn(CO) _6]^+$. Then incorrect statement(s) about metal carbonyls is /are

chemistry coordination chemistry bonding in metal carbonyls metal carbonyls coordination compounds

  1. 'C-O' bond is strongest in the cation and weakest in the anion

  2. 'C-O' bond order is less in the cation than in anion

  3. 'C-O' bond longer in the cation than in anion or neutral carbonyl

  4. 'M-C' bond order is higher in the carbon than in anionic or neutral carbonyl.

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Correct Option: A

If CO ligands are substituted by NO in respective neutral carbonyl compounds then which of the following will not be correct formula?

chemistry coordination chemistry bonding in metal carbonyls metal carbonyls coordination compounds

  1. $Cr(CO) _3(NO) _2$

  2. $Fe(CO) _2(NO) _2$

  3. $Cr(NO) _4$

  4. $Ni(CO) _2(NO) _2$

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Correct Option: A

The V-C distance in ${\text{V}}{\left( {{\text{CO}}} \right) _{\text{6}}}\;{\text{and}}\;\left[ {{\text{V}}{{\left( {{\text{CO}}} \right)} _{\text{6}}}} \right]$ are respectively (in pm) -

chemistry coordination chemistry bonding in metal carbonyls metal carbonyls coordination compounds

  1. 200, 200

  2. 193, 200

  3. 200, 193

  4. 193, 193

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Correct Option: C

Which of the following statement is correct regarding the compound ${\text{''}}\left[ {{{\left( {{\text{CO}}} \right)} _{\text{3}}}{\text{Fe}}{{\left( {{\text{CO}}} \right)} _{\text{3}}}{\text{Fe}}{{\left( {{\text{CO}}} \right)} _{\text{3}}}} \right]{\text{'}}$

chemistry coordination chemistry bonding in metal carbonyls metal carbonyls coordination compounds

  1. The ${{\text{d}} _{{\text{C - O}}}}$ (bridging) is greater than ${{\text{d}} _{{\text{C - O}}}}$ (terminal)

  2. The bond order of bridging C-O bond is greater than that of terminal C-O bond

  3. The E.A.N. value of each Fe-atom is 35

  4. the oxidation state of Fe in this complex is (-1)

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Correct Option: A