Description : Which of the following statements correctly describes the general reactivity of alkynes? (a) An alkyne is an electron-rich molecule and therefore reacts as a nucleophile. (b) The σ bonds ... fail to undergo electrophilic addition reactions. (d) Alkynes are generally more reactive than alkenes.
Last Answer : Alkynes are generally more reactive than alkenes.
Description : Highly reactive coke have lower (A) Porosity (B) Coke reactivity index (CRI) (C) Critical air blast (CAB) value (D) Both (B) and (C)
Last Answer : (C) Critical air blast (CAB) value
Description : Give reason: Iron displaces copper from copper sulphate solution.
Last Answer : Iron is more reactive than copper. Hence it displaces copper from copper sulphate solution.
Description : When a ship floats on water (a) It displaces no water (b) The mass of water displaced is more than the mass of the ship (c) The mass of water displaced is equal to the mass of the ship (d) The mass of water displaced is less than the mass of the ship
Last Answer : Ans:(c)
Description : In arc welding, Argon is used because of its - (1) Low reactivity with metal (2) Ability to lower the melting point of the metal (3) High flammability (4) High calorific value
Last Answer : (1) Low reactivity with metal Explanation: In arc welding, Argon is used as a shielding gas because it is chemically inert and forms no compounds. At the high temperatures that welding requires, the ... to brittle welds and instability in the welding arc. So,argon and other inert gases are sprayed.
Description : In arc welding, Argon is used because of its (1) Low reactivity with metal (2) Ability to lower the melting point of the metal (3) High flammability (4) High calorific value
Last Answer : Low reactivity with metal
Description : In a solution of silver nitrate, a copper plate was dipped. After some time, silver from the solution was deposited on the copper plate. Which metal is more reactive – copper or silver?
Last Answer : More reactive metal displaces a less reactive metal. Hence copper metal is more reactive.
Description : Two ores A1 and A2 of a metal M show the following reactivity: `A_(1)=CuCo_(3).Cu(OH)_(3),S=Cu` `P=Cu_(2)I_(2): G=SO_(2)` . Then `A_(2)` is
Last Answer : Two ores A1 and A2 of a metal M show the following reactivity: `A_(1)=CuCo_(3).Cu(OH)_(3),S=Cu` `P=Cu_(2) ... )` B. `CuO` C. `CuCO_(3)` D. `Cu_(2)S`
Description : The position of three elements A, B and C in the periodic table shown below: a) State whether A is a metal or non-metal. b) State whether C is more reactive or less reactive than A. c) Will C be larger or smaller in size than B?
Last Answer : a) Metals lie on the left side where as non-metals are B C placed on the right side of the periodic table. Group 17 is on the right side of the periodic table, thus element A is non-metal ... size decreases moving from left to right along a period. So atom C will be smaller in size than B.
Description : If the force applied on the body displaces it in the opposite direction of applied force, then the work done is : -Science
Last Answer : Work can be either positive or negative: if the force has a component in the same direction as the displacement of the object, the force is doing positive work. If the force has a component in the direction opposite to the displacement, the force does negative work.
Description : A metallic alloy in general as compared to their pure metal components is (A) More corrosion resistant (B) Having higher melting point (C) Having lower hardness, reactivity and fusibility (D) Having lower electrical conductivity
Last Answer : (A) More corrosion resistant
Description : Amongst the various ores of a metal (M) (sulphide, carbonates, oxides, hydrated or hydroxides) two ores [X] and [Y] show the following reactivity. (i)
Last Answer : Amongst the various ores of a metal (M) (sulphide, carbonates, oxides, hydrated or hydroxides) ... and hydroxide ores D. Carbonate and oxide ores
Description : Which metal is heavier, silver or gold?
Last Answer : Gold
Description : Among the elements of the 3rd period from Na to Ar, pick out the element: (L-2) (a). with highest first ionization enthalpy. (b). with largest atomic radius. (c). that is most reactive non-metal. (d). that is most reactive metal.
Last Answer : (a). Ar has highest first ionization enthalpy. (b). Na has large atomic radius (covalent radius). (c). Cl is more reactive non-metal in 3rd period. (d). Na is most reactive metal in third period.
Description : Statement-1: Zn displaces Ag from the complex `Na[Ag(CN)_(2)]` to give `Na_(2)[Zn(CN)_(4)]` Statement-2:Zn is more electro positive than silver
Last Answer : Statement-1: Zn displaces Ag from the complex `Na[Ag(CN)_(2)]` to give `Na_(2)[Zn(CN)_(4) ... false D. Statement-1 is false but Statement -2 is true
Description : Would you expect benzaldehyde to be more reactive or less reactive in nucleophlic addition reaction than propanal ? Explain.
Last Answer : C-atom of carbonyl group of benzaldehyde is less electrophilic than C-atom of carbonyl group in propanal. Polarity of carbonyl group is in benzaldehyde reduced due to resonance making it less ... group in it is more than in benzaldehyde. This makes propanal more reactive than benzaldehyde.
Description : Fats as compared to oils have (A) More unsaturated glycerides of fatty acids (B) Less unsaturated glycerides of fatty acids (C) Much higher reactivity to oxygen (D) Lower melting point
Last Answer : (B) Less unsaturated glycerides of fatty acids
Description : A force of 10 N displaces a body by a distance of 3 m at an angle 60° to its own direction. Find the amount of work done. -Physics 9th
Last Answer : F=10N,S=2m,θ=600 So, Work=F×Scosθ=10×2cos600 =10×2×21=10J
Description : A floating body always displaces liquid equal to its which thing? -Do You Know?
Last Answer : answer:
Description : A boat will submerge when it displaces water equal to its own: (1) volume (2) weight (3) surface area (4) density
Last Answer : (2) weight Explanation: A boat will float when the weight of the water it displaces equals the weight of the boat and anything will float if it is shaped to displace its own weight of water before ... a column of fluid, pressure increases with depth as a result of the weight of the overlying fluid.
Description : A floating body always displaces liquid equal to its which thing?
Last Answer : Weight
Description : The following drug displaces plasma protein bound phenytoin as well as decreases its metabolism: A. Carbamazepine B. Sodium valproate C. Cimetidine D. Chloramphenicol
Last Answer : B. Sodium valproate
Last Answer : weight
Description : why sodium is less reactive than potassium?
Last Answer : Ans. The ionization enthalpy of potassium is less than that of sodium and the electrode potential of Potassium (-2.95 V) is more negative than that of sodium (-2.71 V) and hence sodium is less reactive than potassium.
Description : (2) it is lighter than air Explanation: Helium is the second lightest element and is the second most abundant element in the observable universe, being present at about 24% of the total elemental mass ... elements combined. A well-known but minor use is as a lifting gas in balloons and airships
Last Answer : Ammonial is a mixture of – (1) aluminium powder and ammonium nitrate (2) aluminium powder and ammonium chloride (3) aluminium powder and ammonium sulphate (4) aluminium powder and potassium nitrate
Description : Variation of a force in a certain region is given by F = 6x^2 – 4x – 8. It displaces an object from x = 1 m to x = 2 m
Last Answer : Variation of a force in a certain region is given by F = 6x2 - 4x - 8. It displaces an ... m in this region. Calculate the amount of work done.
Description : While decreasing linearly from 5 N to 3 N, a force displaces an object from 3 m to 5 m.
Last Answer : While decreasing linearly from 5 N to 3 N, a force displaces an object from 3 m to 5 ... the work done by this force during this displacement.
Description : If a object weighing 50 n displaces a volume of water weighing 10 n what is the buoyant force on the object?
Last Answer : Need answer
Description : Phenylephrine (a) Mimics the transmitter at post-synaptic receptors (b) Displaces transmitter from axonal terminal (c) Inhibits synthesis of transmitter (d) None of the above
Last Answer : Ans: A
Description : When a piece of stone is immersed in water, it displaces water of equal – (1) Density (2) Specific gravity (3) Mass (4) Volume
Last Answer : (3) Mass Explanation: Archimedes' Principle states that upward buoyant force exerted on a body immersed in a fluid is equal to the weight of the fluid the body displaces.
Description : Sodium displaces hydrogen from dilute acids violently but copper does not displace hydrogen from dilute acids. Why?
Last Answer : Sodium is highly reactive than copper. Hence reaction with sodium reacts violently then that of copper.
Description : The lift of a balloon is (A) Increased, as it rises to a higher altitude (B) Due to the weight of the atmospheric air, that it displaces (C) Not dependent on the temperature of the atmosphere (D) None of these
Last Answer : (B) Due to the weight of the atmospheric air, that it displaces
Description : A soil mass coated with a thin layer of paraffin weighs 460 g. When immersed, it displaces 299 cc of water. The weight of paraffin is 10 g. If specific gravity of solids is 2.5 and that of paraffin 0.9, the void ratio of soil, is (A) 0.55 (B) 0.60 (C) 0.65 (D) 0.70
Last Answer : Answer: Option B
Description : When a piece of stone is immersed in water, it displaces water of equal (1) Density (2) Specific gravity (3) Mass (4) Volume
Last Answer : Mass
Description : Aryl halides are less reactive towards nucleophilic substitution as compared to alkyl halides due to (a) Inductive effect (b) Resonance stabilization (c) Tautomerism (d) Stereoisomerism
Last Answer : Resonance stabilization
Description : You are given a set of scales and 12 marbles. The scales are of the old balance variety. That is, a small dish hangs from each end of a rod that is balanced in the middle. The device enables ... than the others. You are asked to both identify it and determine whether it is heavy or light -Riddles
Last Answer : Most people seem to think that the thing to do is weight six coins against six coins, but if you think about it, this would yield you no information concerning the whereabouts of the only different coin. ... . The heavier one is the different coin. If they balance, then 2 is a different light coin.
Description : A parachute descends slowly whereas a stone dropped from the same height falls rapidly, because– (1) Stone is heavier than parachute (2) Special mechanisms are present in parachute (3) A parachute has a larger surface area and air resistance is more (4) None of these
Last Answer : (3) A parachute has a larger surface area and air resistance is more Explanation: Gravity is pulling the man down while friction with the air slows him down. With the parachute out it adds more ... his parachute can make his downward speed vary between about 110 mph and 225 mph-using air resistance.
Description : A parachute descends slowly whereas a stone dropped from the same height falls rapidly, because (1) stone is heavier than parachute (2) special mechanisms are present in parachute (3) a parachute has a larger surface area and air resistance is more (4) None of these
Last Answer : a parachute has a larger surface area and air resistance is more
Description : The high reactivity of fluorine is due to (1) small size of fluorine atom (2) its high electro negativity (3) availability of d-orbitals (4) strong F - F bond
Last Answer : (2) its high electro negativity Explanation: The high reactivity of fluorine is due to its high electro negativity.
Description : Why do American cars sound 'heavier' then European cars?
Last Answer : Because Americans love muscle cars. Didn’t you see the movie American Graffitti? :-)
Description : What is the unit for reactivity?
Last Answer : answer:http://en.wikipedia.org/wiki/Reactivity_series Do you mean the expression in an equation of the reactivity of an elemental metal? I think you can find it on this page in Wiki.
Description : Isotopes differ in - (1) No. of electrons (2) No. of protons (3) No. of neutrons (4) Chemical reactivity
Last Answer : (3) No. of neutrons Explanation: Isotopes have the same atomic number because they are the same element but have a different atomic mass because they contain a different number of neutrons.
Description : Arrange the following in order of decreasing reactivity towards alkanes. HCl, HBr, HI, HF
Last Answer : Ans. HI> HBr> HCl >HF
Description : The increasing order of reactivity among group 1 elements is Li
Last Answer : Ans. In group 1 elements (alkali metals) the reactivity of the metals is mainly due to the electron releasing tendency of their atoms, which is related to ionization enthalpy, Since ... electron gain enthalpy. Since both of them decrease down the group, the reactivity therefore decreases.
Description : Who do double bonds in rubber molecules influence there structure and reactivity.
Last Answer : Ans: Greater the number of double bound the rubber will be less reactive because of greater inter molecular forces of attraction among the monomers.
Description : How do double bonds in the rubber molecule influence their structure and reactivity ?
Last Answer : Due to presence of double bond the rubber molecule show cis-configuration because which the polymer chains can not come close to each other and get boiled but as they have their ... Waals intraction between the molecules consequently they get elastic property, solubility in organic solvents etc.
Description : Arrange the following carboxyl compounds in increasing order of their reactivity in nucleophilic addition reactions. Explain with proper reasoning : Benzaldehyde. p-tolualdeyde, p-nitrobenzaldehyde, Acetophenone.
Last Answer : Ans. Acetophenone is a ketone while all others are aldehydes, therefore it is least reactive. In p-tolualdehyde, there is methyl group (CH3 ) at para position w.r.t. to the ... overall order of increasing reactivity : acetophenone < p-tolualdehyde < benzaldehyde < p-nitrobenzaldehyde.
Description : The higher reactivity of an alkene or alkyne, as compared to an alkane, is due to (a) sigma bonds (b) pi bonds (c) hydrogen bonds (d) None of these
Last Answer : pi bonds
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 : Explain the reactivity of alkali metals towards water.
Last Answer : The alkali metals react with water to form hydroxide and dihydrogen. It may be noted that although lithium has most negative E0 value, its reaction with water is less vigorous than ... explosively with water. They also react with proton donors such as alcohol, gaseous ammonia and alkynes.