Description : Nitrogen shows anomalous behaviour in the group. Why?
Last Answer : Ans: i) Small size ii) High electro negativity iii) Absence of vacant d-orbital.
Description : Why Nitrogen is a gas whereas Phosphorous is a solid?
Last Answer : Ans: Nitrogen molecules have less Vander Waal’s forces of attraction whereas molecular phosphorous has more Vander Waal’s forces of attraction.
Description : Which aerosol deplete ozone layer ?
Last Answer : Ans C.F.C
Description : Write the formula of tear gas .
Last Answer : Ans : CCl3 NO2
Description : Why is helium used in diving apparatus ?
Last Answer : Ans: Because heliun is very low solubility in blood
Description : Why H3 PO3 is dibasic and H3PO4 is tribasic ?
Last Answer : Ans In H3PO3 only two replacable hydrogen but inH3PO4 , three hydrogens are replacable .
Description : Are all the five bonds in PCl5 molecule equivalent ?
Last Answer : Ans – PCl5 has a trigonal bipyramidal structure and the three equatorial p-cl bonds are equivalent . while trhe two axial bonds are different and longer than equatorial bonds.
Description : How is the presence of SO2 detected ?
Last Answer : Ans : 1. It has pungent characteristic smell . 2. It decolourises KMn O4 solution 3. It turns acidified K2 Cr2 O7 green
Description : Why is fluorine stronger Oxidising agent ?
Last Answer : Ans: Due to (a) Low enthalpy of dissociation (b) high enthalpy of Hydration of F-
Description : Halogens have maximum negative electron gain enthalpy in the respective periods in the P. T Why ?
Last Answer : Ans Due to smallest size and high effective nuclear charge , readily accept one electron to acquire noble gas electronic configuration
Description : Which forms of Sulphur show paramagnetic behaviour ?
Last Answer : Ans : In Vapour State sulphurPartly exists as S2 molecule which has two unpaired electrons in the * Orbitals hence exhibit paramagnetic
Description : Give reasons i) H2O is a liquid but H2S a gas. ii) Ammonia has higher boiling point than phosphine ii) Krypton & xenon make compounds.
Last Answer : Ans: i) Hydrogen bond is found in H2O but not in H2S. ii) Hydrogen bond is found in NH3 but not in PH3. iii) Because they have low ionization energy.
Description : Find hybridization and shape i) XeF2 ii) XeO3 iii) XeF4
Last Answer : Ans: i) sp3d, Linear ii) sp3, Pyramidal iii) sp3d2 , Square planar
Description : How is ammonia prepared? Write chemical reaction involved in the Haber’s process.
Last Answer : i) Ammonia is prepared by the combination of hydrogen and nitrogen in the ratio of 3:1. ii) The used catalyst is iron oxide. The promotors are potassium and aluminium oxides. iii) The required conditions are high pressure and moderate temperature. N2 + 3H2 → 2NH3
Description : Give reasons: a) Phosphorous pentachloride is unstable. b) Phosphorous trichloride fumes in moisture.
Last Answer : Ans: a) Because of two longer axial bonds. b) Because it reacts with water and forms hydrochloric acid.
Description : Ortho phosphoric acid is triprotic but phosphoric acid is diprotic. Why?
Last Answer : Ans: Because of their structures ortho phosphoric acid and phosphoric acid have three and two ionisable hydrogen.
Description : Write shape of following molecules: a) Ammonia b) Phosphorous Pentachloride
Last Answer : Ans: a) Pyramidal b) Trigonal bipyramidal
Description : Ammonia is water soluble. Why?
Last Answer : Ans: It forms hydrogen bond with water.
Description : Why is Ammonia a good complexing agent?
Last Answer : Ans: Because of lone pair of electrons on N.
Description : Why is phosphine weaker base than Ammonia?
Last Answer : Ans: P is bigger than N, therefore lone pair of electrons are less available on P than N.
Description : Why Carbon Compounds are relatively inert?
Last Answer : Ans. Because of complete octet of Carbon in its compound.
Description : Assertion: (A) Ethers are relatively inert when compared to `C_(2)H_(5)OH` Reason (R): The hybridization of C and O in `CH_(3)-O-CH_(3) is SP^(3)`
Last Answer : Assertion: (A) Ethers are relatively inert when compared to `C_(2)H_(5)OH` Reason (R): The hybridization of ... R is false D. A is false but R is true
Description : The inert gas which is substituted for nitrogen in the air used by deep sea divers for Breathing is: (1) Neon (2) Argon (3) Krypton (4) Helium
Last Answer : (4) Helium Explanation: Helium is used since it has very low (almost non-existent) narcotic properties. The nitrogen in air is highly narcotic at depth and adding helium allows one to dive without the effects of narcosis (where one's mind is impaired).
Description : The inert gas which is substituted for nitrogen in the air used by deep sea divers for breathing is – (1) Neon (2) Krypton (3) Argon (4) Helium
Last Answer : (4) Helium Explanation: Helium is used by deep sea divers because it reduces the narcosis of nitrogen and it remains below the oxygen toxicity limits. In fact, they use tri mix of Oxygen, helium and a little bit of nitrogen.
Description : Which of the following is an Inert Gas? (1) Hydrogen (2) Nitrogen (3) Oxygen (4) Argon
Last Answer : (4) Argon Explanation: Argon is an inert gas (noble gas) that is placed in Group 18 of the periodic table. It is the most abundant noble gas in Earth's crust, comprising 20.00015% of the crust. Helium ... (Ar), Krypton (Kr), Xenon (Xe), and Radon (Rn) are other noble gases that occur naturally.
Description : The inert gas which is substituted for nitrogen in the air used by deep sea divers for breathing, is - (1) Xenon (2) Krypton (3) Argon (4) Helium
Last Answer : (4) Helium Explanation: Trimix is a breathing gas, consisting of oxygen, helium and nitrogen, and is often used in deep commercial diving. The helium is included as a substitute for some ... possible to create mixes suitable for different depths or purposes by adjusting the proportions of each gas.
Description : The inert gas which is substituted for nitrogen in the air used by deep sea divers for breathing, is (1) Xenon (2) Krypton (3) Argon (4) Helium
Last Answer : Helium
Description : When an inert atmosphere is required in metallurgical operation nitrogen is commonly used. However in the extraction of titanium from `TiCl_(4)` using
Last Answer : When an inert atmosphere is required in metallurgical operation nitrogen is commonly used. ... form nitrogne chloride which inhibits the reaction
Description : Why inert gases are one atom ?
Last Answer : Inert gases are very stable. The last energy level of any atom of these gases is filled by electrons. Electrons do not exchange or share with any of its other elements, not even among themselves. As a result, no bonds are formed, so inert gases are one atom.
Description : What is inert gas ?
Last Answer : An element that does not participate in a chemical reaction is called inert gas. 6 inert gases: Helium ( He), Neon ( Ne) , Argon ( Ar), Krypton ( Kr), Xenon ( Xe), Radon ( Rn)
Description : How many atoms are in the molecule of inert gas ?
Last Answer : Inert gas has 1 atom in its molecule .
Description : The inert gas abundantly found in widely distributed is - (1) Xe (2) Kr (3) He (4) Ar
Last Answer : (4) Ar Explanation: Argon (Ar) is the most prevalent of the noble gases in Earth's crust with the element composing 0.00015% of this crust.
Description : Inert gases are - (1) Miscible with water (2) Not stable (3) Chemically uncreative (4) Chemically very active
Last Answer : (3) Chemically uncreative Explanation: An inert gas is a gas which does not undergo chemical reactions since their valence shells are filled, meaning they don't normally form chemical bonds with other ... inert gases, also called noble gases, are argon, helium, neon, krypton, xenon and radon.
Description : Which of the inert gases can form compounds? (1) Helium (2) Xenon (3) Krypton (4) Argon
Last Answer : (2) Xenon Explanation: Xenon compounds are the most numerous of the noble gas compounds that have been formed. Most of them have the xenon atom in the oxidation state of +2, +4, +6, or ... such as fluorine or oxygen. Some of these compounds have found use in chemical synthesis as oxidizing agents.
Description : The inert gas used as beacon light is - (1) Kr (2) Ar (3) He (4) Ne
Last Answer : (4) Ne Explanation: Neon is used in neon discharge lamps and advertising signs because the neon lights are visible from long distances. Since the light of neon signs has a better penetrating power through ... , the neon signs are also used in beacon lights for the safety of air and sea navigation.
Description : An inert gas mixed with oxygen given to patients suffering from restricted breathing is – (1) Helium (2) Krypton (3) Radon (4) Argon
Last Answer : (1) Helium Explanation: Heliox is a breathing has composed of a mixture of helium (He) and oxygen (O2). Heliox has been used medically since the 1930s, and although the medical community adopted ... its range of medical uses has since expanded greatly, mostly because of the low density of the gas
Description : The number of electrons in the outer shell of the most stable or inert atoms is (1) 1 (2) 5 (3) 3 (4) 8
Last Answer : (4) 8 Explanation: The innermost shell has a maximum of two electrons, but the next two electron shells can each have a maximum of eight electrons.
Description : Why are Be & Mg inert to O2& H2O?
Last Answer : Ans Beryllium and magnesium are chemically inert to oxygen and water because of the formation of an oxide film on their surface. However, powdered beryllium burns brilliantly on ignition in air to ... and nitride. They also react with water with increasing vigour even in cold to form hydroxides.
Description : Why Hydrogen is inert at room temperature?
Last Answer : Ans. Because of high bond dissociation energy of H-H bond.
Description : What will be the effect on equilibrium if (i) a catalyst is added to it (ii) An inert gas is added at constant volume
Last Answer : Ans. (i) The state of equilibrium is not disturbed on adding catalyst rather it is attained quickly. (ii) No effect on state of equilibrium
Description : Give Reason (i)N2 is inert at room temperature. (ii) Overlapping of S orbital with any other orbital forms sigma bonds.
Last Answer : Ans .Due to high bond order (3) , it has high bond dissociation energy ,which is not possible at room temperature (ii)Because s orbital has same electron distribution in all axis/ directions
Last Answer : Beryllium and magnesium are kinetically inert to oxygen and water because of the formation of an oxide film on their surface. However, powdered beryllium burns brilliantly on ignition in air to give BeO ... nitride. They also react with water with increasing vigour even in cold to form hydroxides.
Description : What is the common name of the substance which is inert to nearly all chemicals and is a polymer of tetrafluoroethylene?
Last Answer : ANSWER: TEFLON
Description : Which of the following inert gas atoms is the heaviest? w) xenon x) neon y) radon z) krypton
Last Answer : ANSWER: Y -- RADON
Description : Inert gases are (1) Miscible with water (2) Not stable (3) Chemically unreactive (4) Chemically very active
Last Answer : Chemically unreactive
Description : The inert gas used as beacon light is (1) Kr (2) Ar (3) He (4) Ne
Last Answer : Ne
Last Answer : Xenon
Description : An inert gas mixed with oxygen given to patients suffering from restricted breathing is (1) Helium (2) Krypton (3) Radon (4) Argon