Description : Explain the following , giving reason . (a) Transition metal and many of their compounds show paramagnetic behavior (b) The enthalpy of atomisation of the transition metal is high . (c) The Transition metal generally form coloured compounds .
Last Answer : Ans(a) It is due to unpaired electrons . (b) It is due to strong metallic bond and additional Covalent bonds due to presence of unpaired electron in d- orbitals (c) It is due to presence of unpaired electrons ,they undergo d-d transition .
Description : Why are Ti+2 and other transition metals and their ions paramagnetic ?
Last Answer : Ans: These ions have unpaired electrons in d- subshell.
Description : Why do transition metals have higher I.E than s –block elements ?
Last Answer : Ans: It is due to smaller atomic size than s-block elements , effective nuclear charge is more , terefore I.E is high.
Description : Why do transition metals have high enthalpy of atomization ?
Last Answer : Ans : it is due to strong metallic bonds and additional covalent bonds
Description : Why are Zn , Cd , Hg are not regarded as transition metals ?
Last Answer : Ans: It is because neither they nor their ions have incompletely filled d- orbitals .
Description : Why are transition metal fluorides are ionic in nature where as chlorides and bromides are covalent in nature .
Last Answer : Ans - It is because of fluorine is most electronegative where as Cl and Br are less electro negative . Greater the difference in electro negativity more will be ionic character .
Description : Why is K2Cr2O7 generally preferred over Na2Cr2O7 in a volumetric analysis .Give reason .
Last Answer : Ans : It is because Na2Cr2O7 is hygroscopic in nature that is why it absorbs moisture from atmosphere , therefore its standard solution can not be prepared .
Description : Why are lanthanoid colored and paramagnetic L
Last Answer : Ans It is due to presence of unpaired electrons, they are paramagnetic and they absorb light From visible region and undergoes f-f transition and radiate complementary colour .
Description : Why Mn+2 is more stable than Mn+3 but Fe +3 is more stable than Fe+2 ?
Last Answer : Ans Mn+2 has half filled d- orbital ,therefore it is more stable than Mn+3 Fe+3 has half filled d- orbital, therefore it is more stable than Fe +2 .
Description : Why is Cu+1 diamagnetic and Cu +2 paramagnetic ?
Last Answer : It is because Cu+ does not have unpaired electrons where as Cu+2 has unpaired electrons in d-sub cell .
Description : Why do Zr and Hf show similar properties ?
Last Answer : Ans It is due to similar ionic size which due to lanthanide contraction .
Description : Why are Cr+ , Ag+ & Sc+3 Colour less ?
Last Answer : Ans It is because they do not have unpaired electrons ,therefore can not under goes d-d transition .
Description : Why does V2O5 acts as catalyst ?
Last Answer : Ans : It is because V shows variable O.S .
Description : What is an lanthanoid contraction ? What is its cause ? Give its consequences .
Last Answer : Ans The decrease in atomic and ionic size with increase in atomic no. in lanthanoid series is called lanthanoid contraction . The cause of lanthanoid contraction is poor shielding effect of d and f ... is close resemblance between elements of 4 d and 5 d transition series . due to similar ionic
Description : Why Ce+3 Can be easily Oxidised to Ce+4 ?
Last Answer : Ans : It is because Ce+4 has stable electronic configuration .
Description : What is the highest oxidation state shown by Cr. (24) , Mn(25) ?
Last Answer : Ans: Cr. Shows (+6) and Mn Shows (+7) Oxidation state .
Description : What are d Block Elements ?
Last Answer : Ans: Those elements in which d-orbital are progressively filled up are known as d-orbital.
Description : Application of d- & f- block elements
Last Answer : Application of d- & f- block elements:- 1. Iron and steel used in construction,as catalyst in Haber's process 2. CrO2 is used in magnetic tapes 3. Ni is in hydrogenation 4. W ( ... in contact process 9. Titanium is in nuclear reactions. 10. PdCl2 is in Wacker's process.
Description : The catalytic activity of transition metals and their compounds is ascribed mainly to (1) their chemical reactivity (2) their magnetic behaviour (3) their unfilled d-orbitals (4) their ability to adopt variable oxidation states
Last Answer : (4) their ability to adopt variable oxidation states
Description : Catalytic converters are generally made from (1) Alkaline metals (2) Hydrogen (3) Transition metals (4) Carbon
Last Answer : (3) Transition metals Explanation: Transition metals are used directly as catalysts in the anti-pollution catalytic converters in car exhausts. For example, expensive transition metals such as ... nitrogen monoxide, which are converted to the non-polluting gases nitrogen and carbon dioxide.
Description : Catalytic converters are generally made from : (1) Alkaline metals (2) Hydrogen (3) Transition metals (4) Carbon
Last Answer : Transition metals
Description : What kind of elements generally form coloured compounds?
Description : Explain the following : (i) Low spin octahedral complexes of nickel are not known. (ii) The π-complexes are known for transition elements only. (iii) CO is a stronger ligand than NTL, for many metals. -Chemistry
Last Answer : (i) The electronic configuration of Ni is [Ar] 3d8 4s2 which shows that it can only form two types of complexes i.e. square planar (dsp2) in presence of strong ligand and tetrahedral (sp3) in ... more splitting of d-orbitals and moreover it is also able to form π bond due to back bonding.
Description : What are transition elements? (1) Elements whose two outermost shells are incomplete (2) Elements which possess properties of both, metals and non-metals (3) They have eight electrons in the outermost shell (4) Elements whose three outermost shells are incomplete
Last Answer : (1) Elements whose two outermost shells are incomplete
Description : Which among the following is not a characteristic of transition metals? (1) Tendency to gain electrons (2) Low electronegativity (3) Low ionization energy (4) Malleability
Last Answer : (1) Tendency to gain electrons Explanation: The transition metals have a tendency to lose electrons. Since the electrons in the highest energy level are actually on a lower principal enemy number than the ... ions, the 4s electrons are always lost first; so, they form only cations (positive ions).
Description : The elements that have an outer electron configuration ns2 (read: n - s - 2) are called: w) halogens x) transition metals y) alkaline earths z) noble gases
Last Answer : ANSWER: Y -- ALKALINE EARTHS
Last Answer : Tendency to gain electrons
Description : Give scientific reason of the following : a) Colour blindness is more common in men than in women b) Light coloured clothes are generally worn in summer c) A person is hurt more when he falls ... ground than on soft d) Deforestation causes more floods e) The man-hole covers are generally round
Last Answer : a) Colour blindness is more common in men than in women Women have the sex chromosomes XX, while men have the chromosomes XY. The gene for normal colour vision is found on the X- ... of flowing water. When these trees are cut the natural barriers ultimately vanish and more floods are caused
Description : Copper is the most noble of first row transition metals and occurs in small deposits in serveral countries. Ores of copper include chalcanthite `(CuSO
Last Answer : Copper is the most noble of first row transition metals and occurs in small deposits in serveral ... -reduction. Iron is removed from chalcopyrite as.
Last Answer : Copper is the most noble of first row transition metals and occurs in small deposits in ... self-reduction. Partial roasting of chalcopyrite produces
Description : What is Characteristics of transition metals?
Last Answer : They are malleable.
Description : Why can transition metals form cations with a variety of charges?
Last Answer : Transition metals often form ions without complete octets that'swhy all the stable ions are all cations. You can also tell thatthey form cations because some of the transition metals formcolored compounds and give off light. Light is only given off bycations, not anions.
Description : f-block elements are also called (a) Alkali metals (b) Inner transition elements (c) Transition elements (d) Transuranic elements
Last Answer : Ans:(b)
Description : Which among the following is not a characteristic of transition metals? (1) Tendency to gain electrons (2) Low electro negativity (3) Low ionization energy (4) Malleability
Last Answer : (1) Tendency to gain electrons Explanation: The transition metals have a tendency to lose electrons. Since the electrons in the highest energy level are actually on a lower principal energy number than the ... makes it relatively easy to lose some or all of their electrons to land in stable state.
Description : Pick out the wrong statement. (A) Copper is the metal having the highest electronic conductivity (B) Hardenability & Weldability of metals are inversely related (C) Covalent bonding formed by ... all semiconductor materials (D) Glass transition temperature applies to 'polymers' but not to 'glasses'
Last Answer : Option A
Description : Why do metals conduct electricity but crystals of ionic compounds do not conduct electricity ?
Last Answer : Metals have free electrons. These electrons, created to gain the electromagnetic positivity and octal structure of the metal, flow from the negative side of the electric source to the positive edge ... electrons does not occur in it. Therefore crystals of ionic compounds do not conduct electricity.
Description : Give reason .the compounds of alkaline earth metals are less ionic than alkali metals
Last Answer : Ans This is due to increased nuclear charge and smaller size.
Last Answer : This is due to increased nuclear charge and smaller size.
Description : Which one of the following statements concerning elements in the Periodic Table is correct? A Elements of the same group all have the same number of electrons in the outermost occupied electron shell. B ... (Group 17) are all gases at room temperature. E The Group 13 elements are all metals.
Last Answer : D) Are compounds that exhibit both metallic & non-metallic properties to some extent and are exemplified by elements like germanium, silicon & boron
Description : In which of the following compounds, the oxidation number of the started transition metal is zero.
Last Answer : In which of the following compounds, the oxidation number of the started transition metal is zero. A. `[Ni(CO)_(4)]` ... . `[Fe(H_(2)O)_(3)](OH)_(2)`
Description : The correct statement (s) regarding the binary transition metal carbonyl compounds is (are) (Atomic numbers: Fe = 26, Ni = 28)
Last Answer : The correct statement (s) regarding the binary transition metal carbonyl compounds is (are) (Atomic ... the oxidation state of the metal is increased
Description : Why the transition metal ions or compounds exhibit color ?
Last Answer : Due to incomplete partially filled d- orbitals
Description : (3) reflection of light due to the presence of free electrons Explanation: Lustre (or luster) is the way light interacts with the surface of a crystal, rock, or mineral. The word ... conductivity, and high density. Typically they are malleable and ductile, deforming -under stress without cleaving.
Last Answer : Cloud is a colloidal dispersion of – (1) Air in a dispersion medium of water (2) Fog in a dispersion medium of water (3) Mist in a dispersion medium of air (4) Water drops in a dispersion medium of air
Description : Which metals are generally extracted by electrolyte process? Which positions these metals generally occupy in the periodic table?
Last Answer : Ans. : Electrolytic process is used for the extraction of active metals like Na, Ca, Mg, K, Al etc. where all other methods fail. Except Al and few other metals, these metals belongs to S-block elements of periodic table.
Description : When the pipe Reynold's number is 6000, the flow is generally (A) Viscous (B) Laminar (C) Turbulent (D) Transition
Last Answer : (C) Turbulent
Description : The type of transition curves generally provided on hill roads, is (A) Circular (B) Cubic parabola (C) Lemniscate (D) Spiral
Last Answer : Answer: Option D
Description : The type of curves generally provided on highways, is (A) Critical curve (B) Transition curve (C) Vertical curve (D) All the above
Description : (a) Show on a diagram the transfer of electrons between the atoms in the formation of MgO. Write symbols of cation and anion present in MgO. (b) Name the solvent in which ionic compounds are generally soluble. (c) Why are aqueous solutions of ionic compounds able to conduct electricity? -Chemistry
Last Answer : (b) Ionic compounds are soluble in water. (c) It is because aqueous solutions consist of ions which can move freely in them and carry current.