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 –
Last Answer : Transition Metals
Description : Catalytic Converters are Generally Made from
Description : Catalytic converters are fitted in to automobiles for reducing emission of poisonous gases, having expensive metals namely.
Last Answer : Catalytic converters are fitted in to automobiles for reducing emission of poisonous gases, having ... Lead and Cadmium D. copper and cadmium
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 : Wutomobile catalytic converters cause the carbon monoxide and hydrocarbons which result from incomplete combustion to be converted into what two substances?
Last Answer : ANSWER: CARBON DIOXIDE (CO2) AND WATER (H2O)
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
Description : Sulphur dioxide level in the atmosphere can be reduced by using - (1) more efficient car engines (2) catalytic converters in industry (3) static electricity to attract it in factory chimneys (4) low - sulphur fuels
Last Answer : (4) low - sulphur fuels Explanation: The main source of sulphur dioxide into the atmosphere is from the burning of fossil fuels. Sulphur dioxide can damage plants and reduce crop yields.
Description : Sulphur dioxide level in the atmosphere can be reduced by using (1) more efficient car engines (2) catalytic converters in industry (3) static electricity to attract it in factory chimneys (4) low - sulphur fuels
Last Answer : low - sulphur fuels
Description : 10. Catalytic converters are fitted into automobiles to reduce emission of harmful gases. Catalytic converters change un burnt hydrocarbons into (a) carbon dioxide and water (b) carbon mono oxide (c) methane (d) carbon dioxide and methane.
Last Answer : (a) carbon dioxide and water
Description : Why are transition metals and there compounds generally coloured ?
Last Answer : Ans It is due to present of unpaired electrons in transition metals and their ions , that is why they absorbed light from visible region and undergoes d-d transition and radiate complementary colour .
Description : Electrometallurgical methods of metal extraction is normally used for those metals (A) Whose oxide/ore is not reduced by carbon (B) Which fall in the category of alkali & alkaline earth metals (C) Which stands higher in the electrochemical series of the metal (D) All (A), (B) & (C)
Last Answer : (D) All (A), (B) & (C)
Description : An organic compound ("X") is a disubstituted benzene containing 77.8% carbon and 7.4 % hydrogen. Heating an alkaline solution of "X" with chloroform g
Last Answer : An organic compound ("X") is a disubstituted benzene containing 77.8% carbon and 7.4 % hydrogen. Heating an alkaline ... "Z". "Z" is A. B. C. D.
Description : This noncombustible liquid in its dry form is noncorrosive to common metals except aluminum. About 90% of all of this material which is manufactured goes into the production of chlorofluorocarbons. ... substance: w) carbon tetrachloride x) methylene chloride y) hydrogen chloride z) methyl fluoride
Last Answer : ANSWER: W -- CARBON TETRACHLORIDE
Description : When talking about the periodic table, what are the trends of precipitates as you move down the column of alkaline earth metals?
Last Answer : Homework, eh? :)
Description : How does the of Hydration Enthalpy of alkaline earth metals vary & compare it with alkali metals
Last Answer : Ans The hydration enthalpies of alkaline earth metal ions decrease with increase in ionic size down the group. Be2+> Mg2+ > Ca2+ > Sr2+ > Ba2+ The hydration enthalpies of alkaline earth metal ions ... MgCl2 and CaCl2 exist as MgCl2.6H2O and CaCl2· 6H2O while NaCl and KCl do not form such hydrates.
Description : How does the of Ionization Enthalpy of alkaline earth metals vary in comparison to alkali metals
Last Answer : Ans The alkaline earth metals have low ionization enthalpies due to fairly large size of the atoms. Since the atomic size increases down the group, their ionization enthalpy decreases The first ... enthalpies of the alkaline earth metals are smaller than those of the corresponding alkali metals.
Description : How does the atomic and Ionic Radii of alkaline earth metals vary in comparison to alkali metals
Last Answer : Ans The atomic and ionic radii of the alkaline earth metals are smaller than those of the corresponding alkali metals in the same periods. This is due to the increased nuclear charge in these elements. Within the group, the atomic and ionic radii increase with increase in atomic number.
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.
Description : State as to why: (a) A solution of Na2CO3 is alkaline? (b)alkali metals are prepared by electrolysis of their fused chlorides ? (c)sodium is found to be more useful than potassium ?
Last Answer : Ans. (a) It undergoes hydrolysis to produce a strong base NaOH . (b) When the aq. Solution of any alkali metal is subjected to electrolysis ,H2 instead of the alkali metal is produced at the ... of sugars and amino acids into the cells. Thus, sodium is found to be more useful than potassium.
Description : What are the uses of alkaline earth metals ?
Last Answer : Beryllium is used in the manufacture of alloys. Copper-beryllium alloys are used in the preparation of high strength springs. Metallic beryllium is used for making windows of X-ray tubes. Magnesium ... vacuum tubes. Radium salts are used in radiotherapy, for example, in the treatment of cancer.
Last Answer : The hydration enthalpies of alkaline earth metal ions decrease with increase in ionic size down the group. Be2+> Mg2+ > Ca2+ > Sr2+ > Ba2+ The hydration enthalpies of alkaline earth metal ... and CaCl2 exist as MgCl2.6H2O and CaCl2· 6H2O while NaCl and KCl do not form such hydrates.
Last Answer : The alkaline earth metals have low ionization enthalpies due to fairly large size of the atoms. Since the atomic size increases down the group, their ionization enthalpy decreases The first ionisation ... of the alkaline earth metals are smaller than those of the corresponding alkali metals.
Last Answer : The atomic and ionic radii of the alkaline earth metals are smaller than those of the corresponding alkali metals in the same periods. This is due to the increased nuclear charge in these elements. Within the group, the atomic and ionic radii increase with increase in atomic number.
Last Answer : This is due to increased nuclear charge and smaller size.
Description : Why II group elements are called alkaline earth metals ?
Last Answer : These are called so because their oxides and hydroxides are alkaline in nature and these metal oxides are found in the earth’s crust.
Description : The elements in group 1A of the periodic table are called: w) halogens x) alkaline earths y) alkali metals z) rare earths
Last Answer : ANSWER: Y -- ALKALI METALS
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 : 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 .
Last Answer : Tendency to gain electrons
Description : 10. The metals used in catalytic converter are a.Iron, Copper b. Platinum , Palladium ,and Rhodium c. Gold , Silver , Nichrome d. Mercury ,Lead, Iron
Last Answer : Ans- b. Platinum , Palladium ,and Rhodium
Description : Bayer’s reagent is (1) Alkaline potassium permanganate (2) Acidified potassium permanganate (3) Hydrogen peroxide (4) Bromine water
Last Answer : Alkaline potassium permanganate
Description : Acid Reacts with metals and released............gas. (a) Carbon di oxide (b) Water (c) Hydrogen (d) None
Last Answer : (c) Hydrogen
Description : Generally __________ are subjected to galvanising (i.e., zinc coating). (A) Non-ferrous metals (B) Non-metals (C) Low carbon steels (D) Stainless steel
Last Answer : (C) Low carbon steels
Description : Galvanising is generally done on (A) Non-ferrous metals (B) Low carbon steel (C) Stainless steel (D) Cast iron
Last Answer : (B) Low carbon steel
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 : Alkaline earth metals have low values of electronegativity; which decrease down the group.
Last Answer : Explain : Alkaline earth metals have low values of electronegativity; which decrease down the group.
Description : Are alkaline metals reactive?
Last Answer : Alkaline metals are the most reactive metals.
Description : What is the most active group of nonmetals noble gases alkaline earth halogens alkali metals?
Last Answer : The most active metals are alkali metals.The most active nonmetals are halogens.
Description : Who has the most active group of nonmetals noble gases alkaline earth halogens alkali metals?
Last Answer : Kevin
Description : Alkaline metals when dissolved in ammonium (NH3) act as better conductor and better reducing agent what is the reason behind it ?
Last Answer : Due to formation of solvated or Ammoniated electrons
Description : Which group of elements is called alkaline earth metals ?
Last Answer : 1st A group because the oxides and hydrides are alkaline in nature Among 1A group elements why the element lithium is the most powerful, reducing agent in equivalent state Due to its low sublimation and hydration energy
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.