Description : How the change in pressure at equilibrium position effect the following reaction? PCl5 PCl3 + Cl2
Last Answer : According to Le–chatlier’s principle, by increasing pressure the reaction will move toward less number of moles. In the above reaction, by increasing pressure the reaction will move in backward direction.
Description : In the decomposition of PCl5 represented by, PCl5 ⇌ PCl3 + Cl2, decrease in the pressure of the system will __________ the degree of dissociation of PCl5. (A) Increase (B) Decrease (C) Not alter (D) None of these
Last Answer : (A) Increase
Description : Pick out the wrong statement pertaining to the decomposition of PCl5 represented by, PCl5 ⇌ PCl3 + Cl2.Degree of dissociation of PCl5 will (A) Decrease on addition of Cl2 (B) Increase on addition of ... at constant pressure (C) Decrease on increasing the pressure of the system (D) None of these
Last Answer : (D) None of thes
Description : Which of the following molecules exhibit resonance w) OF3 x) HNO3 y) C2H4 z) PCl3
Last Answer : ANSWER: X -- HNO3
Description : Which of the following compounds has the lowest boiling points? w) CH4 x) CCl4 y) PH3 z) PCl3
Last Answer : ANSWER: W -- CH4
Description : For which molecule can the bonding be described in terms of sp3 hybrid orbitals of the central atom? w) CH4 x) SF6 y) BF3 z) PCL5
Last Answer : ANSWER: B -- CH4
Description : Which of the following molecules has a permanent electric dipole moment? w) H2O x) Cl2 y) CH4 z) N2
Last Answer : ANSWER: W -- H2O
Description : Azo (pron: A-zo) Compounds characteristically are compounds containing the group: w) C2 x) N2 y) O2 z) Cl2
Last Answer : ANSWER: X -- N2 (N = N)
Description : If the volume of a gas changes by a factor of 3, with pressure remaining constant, the temperature in Kelvin will change by a factor of: w) 1/9 x) 1/3 y) 3 z) 9
Last Answer : ANSWER: Y -- 3
Description : Liquid "X" is at equilibrium with its vapor in a cylinder and piston apparatus. When the volume of the space above the liquid is 50 ml and the temperature 25!, the vapor pressure of "X" is 120 torr. What will the ... 25!C? Some liquid is always present. w) 30 torr x) 60 torr y) 120 torr z) 240 torr
Last Answer : ANSWER: Y -- 120 TORR
Description : "Under the same conditions of temperature and pressure, the volumes of reacting gases and of their gaseous products are expressed in ratios of small whole numbers." This law is attributed to: w) Dalton x) Gay-Lussac y) Ramsay z) Avogadro
Last Answer : ANSWER: X -- GAY-LUSSAC
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 catalyst in a first order chemical reaction changes the (A) Equilibrium constant (B) Activation energy (C) Heat of formation of the product (D) Heat of reaction
Last Answer : (B) Activation energy
Description : What purpose does FeCl3 serve in the electrophilic aromatic substitution reaction between chlorine and benzene? (a) It serves as a radical initiator to produce the chlorine radical needed to propagate the ... by reacting with the Cl2 and thereby activates it toward attack by benzene's π electrons.
Last Answer : It serves as a Lewis acid catalyst by reacting with the Cl2 and thereby activates it toward attack by benzene’s π electrons.
Description : The critical temperature is the temperature: w) above which a substance cannot be vaporized x) at which the density is a minimum y) at which solid, liquid, and vapor are in equilibrium z) above which the substance cannot be liquified.
Last Answer : ANSWER: Z -- ABOVE WHICH THE SUBSTANCE CANNOT BE LIQUIFIED.
Description : Brunauer, Emmet and Teller (BET) equation is used to determine the specific surface area of a porous particle but not the pore volume & the porosity of the catalyst bed. Which of the following postulates ... (except the first one) is involved in each of the evaporation process (D) None of these
Last Answer : (B) There is no dynamic equilibrium between successive layer
Description : For the equilibrium Cl2(g) + 2NO(g) ⇌ 2NOCl(g) the concentration of NOCl will increase if the equilibrium is disturbed by ………..
Last Answer : For the equilibrium Cl2(g) + 2NO(g) ⇌ 2NOCl(g) the concentration of NOCl will increase if the equilibrium ... NO c. adding NOCl d. removal of Cl2
Description : In the gaseous phase ammonia formation reaction (N2 + 3H2 ⇌ 2NH3 ), the value of the equilibrium constant depends on the (A) Total pressure of the system (B) Volume of the reactor (C) Temperature (D) Initial concentration of N2 and H2
Last Answer : (C) Temperature
Description : It is a common observation that naturally occurring processes have a particular direction associated with them. For instance, heat flows from a hot body to a colder body. The property of a system ... this natural direction of events is called w) energy x) entropy y) enthalpy z) equilibrium
Last Answer : ANSWER: X -- ENTROPY
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 : In which of the following gaseous phase reactions, the equilibrium of the reaction remains unaffected by pressure changes? (A) 2O3 ⇌ 3O2 (B) N2 + O2 ⇌ 2NO (C) 2NO2 ⇌ N2O4 (D) 2SO2 + O2 ⇌ 2SO3
Last Answer : (B) N2 + O2 ⇌ 2NO
Description : Enrichment of uranium by gaseous diffusion relies on the fact that uranium-235 diffuses through holes in the barriers more readily than uranium-238 does because uranium-235 is: w) a different chemical ... x) a different wavelength. y) resistant to magnetism. z) slightly lighter than uranium-238.
Last Answer : ANSWER: Z -- SLIGHTLY LIGHTER THAN URANIUM-238.
Description : Which of the following properties is lower for a solution than for the pure solvent? w) osmotic pressure x) vapor pressure y) temperature z) boiling point
Last Answer : ANSWER: X -- VAPOR PRESSURE
Description : Foods cooked in salt water compared to unsalted water will: w) cook faster x) boil at a lower temperature y) not be affected in any way z) will cook slower because of the action of the salt
Last Answer : ANSWER: W -- COOK FASTER
Description : The equilibrium constant for the gas phase reactio A + B = C + D is 10-3. The rate of the forward reaction is 10-11 cubic centimeters per molecule per second. What is the rate constant of ... second y) 10-10 cubic centimeters per molecule per second z) 10-14 cubic centimeters per molecule per second
Last Answer : ANSWER: Z -- 10-14 CUBIC CENTIMETERS PER MOLECULE PER SECOND
Description : Which of the following species has the smallest equilibrium separation for its ion-pair? w) KF x) LiF y) BaBr z) NaCl
Last Answer : ANSWER: B -- LiF
Description : In a photosynthesis reaction, chlorophyll is: w) a reactant w) a product y) a catalyst z) an intermediate
Last Answer : ANSWER: Y -- A CATALYST
Description : The man credited with the law relating the temperature and volume of a gas is: w) Thomson x) Boyle y) Charles z) Dalton
Last Answer : ANSWER: Y -- CHARLES
Description : Isobaric processes take place at constant: w) temperature x) volume y) pressure z) energy
Last Answer : ANSWER: Y -- PRESSURE
Description : If the pressure of a gas is increased by a factor of 4, and the temperature is kept constant, the volume of the gas will change by which of the following factors? w) 4 x) 2 y) 1/2 z) 1/4
Last Answer : ANSWER: Z -- 1/4
Description : The molar volume of which two elements is the same at standard temperature and pressure? w) fluorine and bromine x) fluorine and iodine y) fluorine and chlorine z) bromine and iodine
Last Answer : ANSWER: Y -- FLUORINE AND CHLORINE
Description : In the reaction, H2 +I2 ⇌ 2HI, addition of an inert gas will (A) Increase the partial pressure of H2 (B) Increase the partial pressure of I2 (C) Increase the total pressure and hence shift the equilibrium towards the right (D) Not affect the equilibrium conditions
Last Answer : (D) Not affect the equilibrium conditions Share
Description : For the reversible exothermic reaction, N2 + 3H2 ⇌ 2NH3, increase of pressure would (A) Shift the equilibrium towards right (B) Give higher yield of NH3 (C) Both (B) and (C) (D) Neither (A) nor (B)
Last Answer : (C) Both (B) and (C)
Description : Which one of the following statements regarding a catalyst is not correct? A An enzyme is a catalyst that only binds certain substrates. B An enzyme is a protein that is a highly ... increasing the activation energy. D Catalysts do not alter the equilibrium constant for a chemical reaction.
Last Answer : C Catalysts increase the rate of a reaction by altering the mechanism, thereby increasing the activation energy.
Description : A catalyst is a substance which (a) Changes the equilibrium of a reaction so that the concentration of the product increases (b) Increases the rate of reaction and increases the equilibrium concentration of products (c) Hastens the attainment of equilibrium (d) Increases the activation energy
Last Answer : Ans:(c)
Description : A Catalyst (A) Increases the equilibrium concentration of the product (B) Changes the equilibrium constant of the reaction (C) Shortens the time to reach the equilibrium (D) None of these
Last Answer : (C) Shortens the time to reach the equilibrium
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 : Pick out the correct statement. (A) A catalyst speeds up the forward reaction but slows shown the reverse reaction (B) Addition of catalyst changes the equilibrium constant (C) Pressure changes do not change the equilibrium concentrations (D) The composition of equilibrium is changed by catalyst
Last Answer : (C) Pressure changes do not change the equilibrium concentrations
Description : 45. When Cl2 gas reacts with hot and concentrated sodium hydroxide solution, the oxidation number of chlorine changes from (1) Zero to + 1 and zero to –3 (2) Zero to +1 and zero to –5 (3) Zero to –1 and zero to + 5 (4) Zero –1 and zero to + 3
Last Answer : Zero to –1 and zero to + 5
Description : If a piece of metal at -20 degrees Celsius is added to an ice and water mixture in equilibrium at 0 degrees Celsius, the amount of ice will: w) Increase x) Remain the same y) Decrease
Last Answer : ANSWER: W -- INCREASE
Description : When you push down on the piston of a bicycle pump, the air is compressed into a smaller volume, which causes its temperature to: w) decrease x) increase y) stay the same
Last Answer : ANSWER: X -- INCREASE
Description : The Doppler Effect predicts that the spectrum of light from a visible body moving AWAY from the Earth will experience a shift in frequency when viewed from Earth. This particular shift is known as the: w) Blue shift x) Neutral shift y) Red shift z) Dirac shift
Last Answer : ANSWER: Y -- RED SHIFT
Description : Can anyone help me with this? Chlorine and carbon monoxide gases are mixed in a 1.00L container and the following equilibrium is established: CO(g) + Cl2(g) COCl2(g).. Initially 1.5 mol of ... monoxide. At equilibrium, 0.8 mol of COCl2(g) was found. How do you calculate the percent reaction?
Last Answer : For a start, your equation isn't balanced; it should be Cl2 (Cl2, not 2Cl, because of HONClBrIF). Given this, if we assume the reaction goes to completion, 1.5 mol Cl2 will produce 1.5 mol ... .3% Incidentally, is that supposed to be CO or Co? It has no effect on the calculation, just curious.
Description : A negative heat of solution indicates that: w) an endothermic dissolving process occurs x) solute solubility increases with rising solution temperature y) solute solubility decreases with rising solution temperature z) super-saturation conditions exist
Last Answer : ANSWER: Y -- SOLUTE SOLUBILITY DECREASES WITH RISING SOLUTION TEMPERATURE
Description : Pick out the correct statement. (A) A lower temperature favours the reaction of lower activation energy (B) The dispersion number for a reactor/vessel is uL/D (C) The rate controlling step in ... step (D) Pore volume and porosity of a catalyst is measured by BrunauerEmmett-Teller (BET) technique
Last Answer : (A) A lower temperature favours the reaction of lower activation energy
Description : To increase the solubility of a gas in a liquid as much as possible, we would use: w) low temperature and high pressure. x) high temperature and high pressure. y) high temperature and low pressure. z) low temperature and low pressure.
Last Answer : ANSWER: W -- LOW TEMPERATURE AND HIGH PRESSURE.
Description : A family of organic compounds whose molecules will add water under an acid catalysis and change into alcohols are the: w) alkenes x) alkanes y) aromatic hydrocarbons z) cycloalkanes
Last Answer : ANSWER: W -- ALKENES
Description : In a monopoly market, an upward shift in the market demand results in a new equilibrium with A.A higher quantity and a lower price B.A higher quantity and the same price C.A higher quantity and higher price D.All of the above
Last Answer : C.A higher quantity and higher price
Description : Buffer solutions show which one of the following traits: w) absorb acid and base with only small changes in pH x) indefinite stability y) high elasticity z) abnormal density
Last Answer : ANSWER: W -- ABSORB ACID AND BASE WITH ONLY SMALL CHANGES IN pH
Description : A cobalt chloride solution soaked into a piece of cotton can be used as an indicator for changes in humidity levels. Pink indicates a high-humidity environment and blue a low-humidity environment. What ... the cobalt's waters of hydration. z) This is an illustration of the Schrodinger principle.
Last Answer : ANSWER: Y -- THE LOSS AND READSORPTION OF THE COBALT'S WATERS OF HYDRATION.