Description : What happens to the total mass of the reactants in a chemical reaction?
Last Answer : Need answer
Description : It is important to balance the chemical equations to satisfy the law of conservation of mass. Which of the following statements of the law is incorrect? (a) The total mass of the elements present in ... the reaction (d) Mass can neither be created nor can it be destroyed in a chemical Reaction.
Last Answer : Answer : (c) The chemical composition of the reactants is the same before and after the reaction
Description : After a chemical reaction, the total mass of reactants and products [MP PMT 1989] (A) Is always increased (B) Is always decreased (C) Is not changed (D) Is always less or more
Last Answer : (C) Is not changed
Description : "The rate at which a substance reacts is proportional to its active mass and the rate of a chemical reaction is proportional to the product of active masses of the reacting substances". This is the (A) Lewis- ... (B) Statement of Van't Hoff Equation (C) Le-Chatelier's principle (D) None of these
Last Answer : (D) None of these
Description : Two masses, one of the 10kg and the other unknown, are placed on a scale in a region where g = 9.67 m/sec2 . The combined weight of these two masses is 174.06 N. Find the unknown mass in kg. a. 20 kg b. 19 kg c. 18 kg d. 17 kg formula: m=Fg k / g
Last Answer : 18 kg
Description : The order of a chemical reaction is (A) An experimentally determined quantity (B) Always equal to the total stoichiometric number of reactants (C) Never fractional (D) None of these
Last Answer : (A) An experimentally determined quantity
Description : Pick out the wrong statement. (A) Wine, rum & Vodka are prepared by the formulation of fruit juice, sugar beet & rye respectively (B) Protein catalysts are called enzymes (C) The rate ... concentration of reactants at high concentration of enzymes (D) Total sugar content in molasses is about 10%
Last Answer : (D) Total sugar content in molasses is about 10%
Description : Pick out the wrong statement. (A) Exit age description function (E) and internal age distribution function (I) are related as, E = -(dI/dθ) (B) Chemisorption studies are useful in the ... energy (D) A catalyst increases the potential energy barrier over which the reactants must pass to form products
Last Answer : (D) A catalyst increases the potential energy barrier over which the reactants must pass to form products
Description : If the only reactants of a reaction were zn and hci what does the law of conservation of mass say about the products?
Description : According to the 'law of mass action', the rate of reaction is directlyproportional to the (A) Equilibrium constant (B) Volume of the reaction vessel (C) Nature of the reactants (D) Molar concentration of the reactants
Last Answer : (D) Molar concentration of the reactants
Description : Pick out the correct statement. (A) A catalyst does not change AH of the reaction (B) A catalyst changes the equilibrium point (C) Law of mass action was suggested by Le-Chatelier (D) The difference between the energy of reactants and that of the products is the activation energy
Last Answer : (A) A catalyst does not change AH of the reaction
Description : Are the reactants always completely used up in a chemical reaction?
Description : Rate constant for a first order reaction does not depend upon reaction time, extent of reaction and the initial concentration of reactants; but it is afunction of reaction temperature. In a chemical reaction, the time required to ... Then the order of this reaction is: (A) 0 (B) 1 (C) 2 (D) 3
Last Answer : (B) 1
Description : Reverse reaction in a chemical equilibrium is favoured by the (A) Removal of one of the products regularly (B) Increase in the concentration of one of the products (C) Increase in the concentration of one of the reactants (D) None of these
Last Answer : (B) Increase in the concentration of one of the products
Description : In a reversible chemical reaction having two reactants in equilibrium, if the concentration of the reactants are doubled, then the equilibrium constant will (A) Remain the same (B) Be halved (C) Also be doubled (D) Become one fourth
Last Answer : (A) Remain the same
Description : Which of the following will favour the reverse reaction in a chemical equilibrium reaction? (A) Increasing the concentration of one of the reactants (B) Increasing the concentration of one or more of the products (C) Removal of at least one of the products at regular interval (D) None of these
Last Answer : (B) Increasing the concentration of one or more of the products
Description : For a zero order chemical reaction, the (A) Half life period is directly proportion to the initial concentration of the reactants (B) Plot of products concentration with time is a straight line through the origin (C) Products concentration increases linearly with time (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : A catalyst (A) Initiates a reaction (B) Lowers the activation energy of reacting molecules (C) Is capable of reacting with any one of the reactants (D) Cannot be recovered chemically unchanged at the end of a chemical reaction
Last Answer : (C) Is capable of reacting with any one of the reactants
Description : In an exothermic chemical reaction, the reactants compared to the products have (A) Higher temperature (B) More energy (C) Less energy (D) Same energy
Last Answer : (B) More energy
Description : The rate constant of a chemical reaction decreases by decreasing the (A) Pressure (B) Concentration of reactants (C) Temperature (D) Duration of reaction
Last Answer : (C) Temperature
Description : Pick out the wrong statement. (A) Use of different catalysts in a reversible catalytic chemical reaction does not change the equilibrium composition (B) Alumina is added as a promoter to ... Arrhenius plot (D) Presence of inerts affects the equilibrium conversion of reactants in a chemical reaction
Last Answer : (C) Activation energy for a reaction is obtained from the intercept of the Arrhenius plot
Description : Rate of a chemical reaction is not influenced by the (A) Catalyst (B) Temperature (C) Reactants concentration (D) Number of molecules of reactants taking part in a reaction
Last Answer : (D) Number of molecules of reactants taking part in a reaction
Description : The excess energy of reactants in a chemical reaction required to dissociate into products is termed as the __________ energy. (A) Activation (B) Potential (C) Binding (D) Threshold
Last Answer : (A) Activation
Description : What is the order of a chemical reaction in which doubling the initial concentration of the reactants doubles the half life time of the reaction? (A) 0 (B) 1 (C) 2 (D) 3
Last Answer : (A) 0
Description : Velocity of a chemical reaction (A) Decreases with increase in temperature (B) Increases with increase of pressure of reactants for all reactions (C) Decreases with increase of reactant concentration (D) None of these
Description : Pick out the correct statement. (A) In catalytic reactions, the catalyst reacts with the reactants (B) A catalyst initiates a chemical reaction (C) A catalyst lowers the activation energy of ... molecules (D) A catalyst cannot be recovered chemically unchanged at the end of the chemical reaction
Last Answer : (C) A catalyst lowers the activation energy of the reacting molecules
Description : Pick out the wrong statement. (A) 'Hold back' is defined as the fraction of material that stays longer than the mean residence time (B) Study of non-ideal flow reactor is done experimentally ... final stages of reaction (D) A batch reactor cannot be used to study the kinetics of catalytic reaction
Last Answer : (D) A batch reactor cannot be used to study the kinetics of catalytic reaction
Description : If the rate of a chemical reaction becomes slower at a given temperature, then the (A) Initial concentration of the reactants remains constant (B) Free energy of activation is lower (C) Entropy changes (D) Free energy of activation is higher
Last Answer : (D) Free energy of activation is higher
Description : The equilibrium constant ‘K’ of a chemical reaction depends on (A) Temperature only (B) Pressure only (C) Temperature and pressure (D) Ratio of reactants
Last Answer : (A) Temperature only
Description : Rate of a chemical reaction is independent of the concentration of the reactants for a __________ reaction. (A) Zero order (B) Third order (C) Consecutive (D) None of these
Last Answer : (A) Zero order
Description : The rate constant of a chemical reaction increases by increasing the (A) Temperature (B) Pressure (C) Reactant's concentration (D) None of these
Last Answer : (A) Temperature
Description : Rate of a chemical reaction is not affected by the (A) Catalyst (B) Temperature (C) Reactant’s concentration (D) Number of molecules of reactants taking part in the reaction
Last Answer : (D) Number of molecules of reactants taking part in the reaction
Description : At very high concentration of enzymes, the rate of fermentation chemical reaction is __________ the concentration of reactants. (A) Independent of (B) Directly proportional to (C) Inversely proportional to (D) Proportional to the square of
Last Answer : (A) Independent of
Description : What is the name for a chemical reaction that builds up larger molecules? a. dehydration synthesis b. hydrolysis c. reactants d. products
Last Answer : a. dehydration synthesis
Description : If the molar heat capacities (Cp or Cv) of the reactants and products of a chemical reaction are identical, then, with the increase in temperature, the heat of reaction will (A) Increase (B) Decrease (C) Remain unaltered (D) Increase or decrease; depends on the particular reaction
Last Answer : (C) Remain unaltered
Description : In a reversible chemical reaction (where, Δx = number of moles of products-number of moles of reactants) (A) Addition of inert gas favours the forward reaction, when Δx is positive (B) Pressure has no effect on equilibrium, when Δn = ... any value of Δx (+ ve, - ve) or zero) (D) All 'a', 'b' & 'c'
Last Answer : D) All 'a', 'b' & 'c'
Description : What happens when a catalyst is added to a system at equilibrium? A The reaction follows an alternative pathway of lower activation energy. B The heat of reaction decreases. C The potential ... decreases. D The potential energy of the products decreases. E The rate of chemical reaction decreases.
Last Answer : A The reaction follows an alternative pathway of lower activation energy.
Description : The rate of a chemical reaction can be affected by: w) temperature x) concentration of products y) concentration of reactants z) all of the above
Last Answer : ANSWER: Z -- ALL OF THE ABOVE
Description : The atomic masses of three elements X, Y and Z having similar chemical properties are 7, 23 and 39 respectively. a) Calculate the average atomic mass of elements X and Z. b) How is the ... this example? d) Give another example of a set of elements which are classified according to this law.
Last Answer : a) The average atomic mass of X and Z = 7 39 2 46 2 23 b) The average atomic mass of X and Z is equal to the atomic mass of Y c) The law illustrated in this example is Dobereiner’s law of triads. d) Another example of Dobereiner’s law is Calcium, Strontium and Barium.
Description : In a chemical reaction, __________ are conserved. (A) Ions (B) Masses (C) Atoms (D) Both (B) & (C)
Last Answer : (D) Both (B) & (C)
Description : Which of the following reactants on reaction with conc. NaOH followed by acidification gives following lactone as the product?
Last Answer : Which of the following reactants on reaction with conc. NaOH followed by acidification gives following lactone as the product? A. B. C. D.
Description : If the reactants of a reaction are 2AgCIO3 and Na2CO3 which could be a product?
Last Answer : Ag2CO3 -apex
Description : A combination reaction occurs when two or more reactants form one product T or F?
Last Answer : T
Description : The reaction in which product mole- cules react and give back the original reactants is called?
Last Answer : Backward reaction
Description : 25. In a reaction, A + B Product, rate is doubled when the concentration of B is doubled, and rate increases by a factor of 8 when the concentrations of both the reactants (A and B) are doubled, rate law for the reaction can be ... Rate = k[A] [B]2 (3) Rate = k[A]2 [B]2 (4) Rate = k[A] [B]
Last Answer : Rate = k[A]2 [B] (
Description : According to Newton's law of universal gravitation, any two particles of finite mass attract one another with a force which is A. Inversely proportional to the product of their masses and ... the product of their masses and inversely proportional to the square of their distance apart
Last Answer : Directly proportional to the product of their masses and inversely proportional to the square of their distance apart
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 : (3) two light nuclei combine to form a heavy nucleus Explanation: Nuclear fusion is the process of making a single heavy nucleus (part of an atom) from two lighter nuclei. The difference in mass ... . Fusion is the process that powers active or "main sequence" stars, or other high magnitude stars.
Last Answer : Helium is added to the oxygen supply of deep sea divers because it is - (1) less poisonous than nitrogen (2) (2) Lighter than nitrogen (3) Readily miscible with oxygen (4) less soluble in blood than nitrogen at high pressure