Free MCQs & Online Quiz Practice for Exams

Q: 18-carat gold contains approximately: (2015 ETEA)

A) 70–75% Au and 15–20% Cu

B) 70–75% Au and 20–25% Cu

C) 75–80% Au and 20–30% Cu

D) 100% Au with no Cu

Q: Which of the following is a noble metal? (2015 ETEA)

A) Ar

B) Sn

C) Gold

D) Ro (typo)

Q: In the equilibrium CrO₄²⁻ + 2H⁺ ⇌ Cr₂O₇²⁻ + H₂O (orange ⇄ yellow), if acid is added, the colour changes from orange to yellow because: (2016 ETEA)

A) CrO₂ acts as a base

B) An addition of base changes the colour to yellow

C) Addition of acid changes oxidation state of Cr from +6 to +4

D) Both A and B

Q: When a small amount of ammonia is added to CuSO₄ solution a blue ppt of [Cu(H₂O)₂(OH)₂] is formed; on addition of excess ammonia the product formed is: (2016 ETEA)

A) [Cu(H₂O)₂(NH₃)₄(OH)₂]

B) [Cu(NH₃)₂(OH)₂]

C) [Cu(NH₃)(H₂O)₂]

D) [Cu(NH₃)₆(H₂O)₃]⁺

Q: Which hydrated cations of transition series impart a blue color: (2016 ETEA)

A) Cr³⁺

B) Co²⁺

C) Cu²⁺

D) Mixture

Q: The colours of MnO₄⁻ and Mn²⁺ solutions in water are respectively: (2016 ETEA)

A) Intense dark purple and colourless

B) Light purple and colourless

C) Intense dark purple and brown

D) Light purple and brown

Q: Chromium compounds in which oxidation state of chromium is +2 behave as a: (2016 ETEA)

A) Strong oxidizing agent

B) Strong reducing agent

C) Very weak oxidizing agent

D) Very weak reducing agent

Q: What is the formula of dichloro-bis-ethylenediamine cobalt(II)? (2016 ETEA)

A) [Co(en)₂Cl₂]

B) [Co(en)₂Cl₂]⁺

C) [Co(en)₂Cl₂]⁻

D) [Co(en)₂Cl₂] (stereo)

Q: Complementary colour of orange is: (2016 ETEA)

A) Red

B) Green

C) Green-blue

D) Yellow

Q: Complexes exist in various coordination numbers; which coordination number is less common? (2017 ETEA)

A) 2

B) 4

C) 5

D) 6

Q: Choose the mineral which is not a chromium ore: (2017 ETEA)

A) Chromite (chrome ironstone)

B) Chrome ochre

C) Cord

D) Chalcocite

Q: Vanadium compounds exist in oxidation states +5,+4,+3,+2; compounds in +3 and +2 states behave as: (2017 ETEA)

A) Good oxidizing agents

B) Good reducing agents

C) Weak oxidizing agents

D) Weak reducing agents

Q: Coordination-number-6 complexes having d²sp³ hybridization exist in: (2017 ETEA)

A) Tetrahedral shape

B) Square planar shape

C) Trigonal bipyramidal shape

D) Octahedral shape

Q: Most solutions containing ferric ions are usually yellow or yellowish brown; this is due to formation of: (2017 ETEA)

A) [Fe(H₂O)₆]³⁺

B) [Fe(H₂O)₅(OH)]²⁺

C) [Fe(H₂O)₄(OH)₂]

D) other

Q: Arrange chromium oxides in increasing acidic character: (2017 ETEA)

A) CrO > Cr₂O₃ > CrO₂

B) CrO₂ > Cr₂O₃ > CrO

C) Cr₂O₃ > CrO > CrO₂

D) CrO₂ > CrO > Cr₂O₃

Q: Many hexaaqua complex ions undergo reaction with water to give [M(H₂O)₅(OH)]⁺ + H⁺; the reaction is classed as: (2017 ETEA)

A) Redox

B) Acid-base

C) Decomposition

D) Substitution

Q: In movies, an artificial blood red solution is used; which complex ion is used for this solution? (2017 ETEA)

A) [Fe(H₂O)₆]²⁺

B) [Cu(NH₃)₄(H₂O)₂]²⁺

C) [Fe(SCN)(H₂O)₅]²⁺

D) [Fe(H₂O)₆]³⁺

Q: Choose the correct name of the complex K[PtCl₅]: (2017 ETEA)

A) Potassium hexachloroplatinum(V)

B) Potassium hexachloroplatinate(VI)

C) Potassium hexachloroplatinate(IV)

D) Potassium chloroplatinate

Q: In the chromate–dichromate equilibrium, if NaOH is added, the correct statement is: (2017 ETEA)

A) Equilibrium shifts to the right

B) Cr₂O₇²⁻ is decomposed to CrO₄²⁻

C) Equilibrium unaffected

D) Equilibrium shifts to the left

Q: The reaction between persulfate ions and iodide ions S₂O₈²⁻ + 2I⁻ → 2SO₄²⁻ + I₂ is best catalyzed by: (2017 ETEA)

A) Ni²⁺

B) Fe²⁺ & Fe³⁺

C) Fe³⁺ alone

D) Fe²⁺ alone