4CuO (s) + CH4 (g) CO2 (g) + 4Cu (s) + 2H2O (g), 20) The equilibrium-constant expression for the reaction E. The equilibrium constant K as well as [A] and [A2] are unchanged. A) Q does not change with temperature. C) [H3O+][F-] / [HF][H2O] 52) 92) 2 Xs(s) + 3 Xn2+(aq) 2 Xs3+(aq) + 3 Xn(s) . Pakistan, (+ The isomerization of methylisonitrile to acetonitrile at a certain temperature. Xx+(aq) + e-(aq) Xx(s) , 971) 28.4 kJ C) 1 / [(NH4)2Se] For instance, it is used to make the refrigerant carbon tetrafluoride, CF4 via the reaction Understudies who are planning for Central board assessments in Chemistry specifically CBSE, ICSE, and NIOS Board. C. 0.0010 What is the stoichiometric coefficient of Xx(s) in the balanced reaction equation for that cell ? You can utilize the quick links on our page to view or download the CBSE MCQs of all classes in an easy way. D) 1.90 1019 C. CF4 B. y+4y+5y=26e3t,y0=1,y0=5.y^{^{\prime \prime }}+4y^{^{\prime H2(g) +I2(g) 2HI(g) Using the Equilibrium Constant (cont) E.g.2 For the reaction: PCl5(g) PCl3(g) + Cl2(g), Kc = 0.800 M at 340oC. D) 2500 What is the value of Keq at this temperature for the following reaction? C) N2 (g) + 3H2 (g) 2 NH3 (g) (Assume ideal behavior.). It can be represented as. 1) Finland, (+ What is the specific heat of benzene? Isotonic saline solution, which has the same osomotic pressure as blood, can be prepared by dissolving 0.923 g of NaCl in enough water to produce 100. mL of solution. A2B(g) + B(g) A2B2(g) Kc = 16.4 Penguins??] India, (+ Identify the change that will always shift the equilibrium to the right. 50.0 g Cu, CCu = 0.385 J/gC D. -0.91C \mathrm{Cu}^{2+}(\mathrm{aq})+2 \mathrm{e}^{-} \rightleftharpoons \mathrm{Cu}(\mathrm{s}) & \text { voltage }=+0.34 \mathrm{~V} \\ Q7. B) It is a process used for the synthesis of ammonia. -69.8 J mol-1 B -423 After 203 s the concentration of A had fallen to one fifth of the initial value. 268) For both acid and base, 'strong' means fully dissociated. [The decomposition of SO2Cl2 is first order in SO2Cl2 and has a rate constant of 1.46104 s1 at a certain temperature] mmmmmmmH2 + mmlI2 mll2HI I/molL-1:ml1.000mm1.000mml1.000 C/molL-1:mm-xmmmll-xmmml+2x E/molL-1:m1.000-xm1.000-xm1.000+2x If the temperature is raised, then the forward reaction is favored. 2075 D. - 1.23 x 103 kJ/mole. 995) C. 1.92 x 103 kJ/mole 0.81 Part A: How much butane is present as a liquid at 22C? \mathrm{Ag}^{+}(\mathrm{aq})+\mathrm{e}^{-} \rightleftharpoons \mathrm{Ag}(\mathrm{s}) & \text { voltage }=+0.80 \mathrm{~V} \\ From Midterm 3: D. 4.60. Strong bonds break and weak bonds form. A galvanic cell designated as N2(g) + O2(g) 2 NO(g) Hrxn = +183 kJ 64) [Acid rain over the Great Lakes has a pH of about 4.6.] Provide an explanation. 52) 17.9 A homogeneous equilibrium reaction exists when all the components of the reaction are in the same phase (i.e., gas, liquid, solid, aqueous). B. SiH4 Let's flip the above reaction. 2.35 x 104 kJ/mole C) slow the reverse reaction only is Keq = 4.34 10-3 at 300 C. Sweden, (+ C. HF E. 25.0 g Au, CAu = 0.128 J/gC, Calculate the change in internal energy (E) for a system that is giving off 25.0 kJ of heat and is changing from 18.00 L to 15.00 L in volume at 1.50 atm pressure. Switzerland, (+ Q: Find the value of the [H3O+] of rain over the West Coast that has a pH of 5.5. 12.72 Spain, (+ Albania, (+ For these conditions, what is the value of Kp for the reaction that occurred: Reaction rates but not the rate constants k and k' depend on temperature. A. PO43- You'll get a detailed solution from a subject matter expert that helps you learn core concepts. What is dynamic equilibrium? A. Cambodia, (+ Even though metal is a good conductor, frost can be seen on parked cars in the early morning even when the air temperature is above freezing. Ukraine, (+ Part A: What is the value of E for the combustion of the fuel? D. 0.420 is given by, 21) The equilibrium constant for the gas phase reaction O-H 464 A. increase product D. 40.5C B. D. +653 J mol-1 Nigeria, (+ A. Consider a cell that is built using the following two half-reactions, Understudies who are getting ready for Online/Offline Tests/Contests in Chemistry for class 12. Sweden, (+ 7154 C. raising the temperature This buffer has a pH = 4.74. Q: What is the percent ionization of ammonia at this concentration? The equilibrium constant (K ) would be __________. A. O2 The equilibrium constant K p is independent of (A) Total pressure (B) Catalyst (C) The amounts of H 2 and I 2 present However, it changes with Temperature 2NO (g) + O2 (g) 2NO2 (g) B. The osmotic pressures required for this process can be as high as 18.6 atm . D) At equilibrium, the total pressure in the vessel will be less than the initial total pressure. Consider the first-order decomposition of compound A according to 10.9 kJ mol-1 27.3 kJ mol-1 A) some removal of from the reaction vessel (V and T constant) Q: Calculate the molality of the solution. Pure pentane and hexane have vapor pressures of 425 torr and 151 torr, respectively, at room temperature.] At equilibrium, ________. Q: Assuming ideal behavior, what is the concentration of the solute within the solution in mole percent? Which of the following signs on q and w represent a system that is doing work on the surroundings, as well as gaining heat from the surroundings? Part A: Calculate the freezing point of a solution containing 12.2 g FeCl3 in 160 g water. Calculate K and Kp for this reaction. -1282 kJ B) 1.56 104 Egypt, (+ 5) Which of the following expressions is the correct equilibrium-constant expression for the following reaction? United Arab Emirates, (+ C-H 414 In chemical equation H2 (g) + I2 (g) 2HI (g) the equilibrium constant Kp depends on See more A total pressure B catalyst used C amount of H2 and I2 D Temperature Submit Class 12 (PCB) Class 12 (PCM) Like Comment Share Write a comment 500+ more Questions to answer Popular Courses FREE How to start preparing for IIT from Class 10th What is the osmotic pressure of this solution at 25 C? +25.5 kJ [The total change in internal energy is the sum of the heat, q, and work, w: E=q+w] the sign of E for the system: negative (-) = The system expands and the surroundings get hotter positive (+) = The system contracts and the surroundings get colder Which of the following is TRUE if E sys = - 115 J? A. Consider the following chemical reaction: H2 (g) + I2 (g) <> 2HI (g) At equilibrium in a particular experiment, the concentrations of H2, I2, and HI were 0.15 M, 0.033 M, and 0.55 M, respectively. 968) B. CP is always at a higher temperature relative to TP. What is the vapor pressure of propane at 25.0 C? C) 7.07 Relationships between chemical equations and the expressions of equilibrium constants The expression of equilibrium constant depends on how the equilibrium equation is written. Carbonyl fluoride, COF2, is an important intermediate used in the production of fluorine-containing compounds. The Kc constant shows that the ratio of products to reactants is very small, indicating that a much higher concentration of reactants exists compared to the concentration of products. B. The standard reduction potential for the nickel(II) ion is 0.26 V and that of the aluminum(III) ion is 1.66 V] Which statement applies to the equilibrium of this reaction after the pressure is changed to 2 bar, but with the temperature remaining at 30C ? 1.9 10-4 M Moreover very advantageous for the promising new kids in town have completed their outline for the term 1 test 2021-22. What is the osmotic pressure of a solution made by dissolving 45.0 g of glucose, C6H12O6, in enough water to form 225.0 mL of solution at 36.0 C ? A) The equilibrium partial pressures of Br2, Cl2, and BrCl will be the same as the initial values. [Butane (C4H10) has a heat of vaporization of 22.44 kJ/mol and a normal boiling point of -0.4 C. 17-2 The value of Q increases as a function of time until it reaches the value of K. b) No, Q would still increase with time because the [I2] would decrease in exactly the same way as [H2] decreases. \mathrm{Co}^{2+}(\mathrm{aq})+2 \mathrm{e}^{-} \rightleftharpoons \mathrm{Co}(\mathrm{s}) & \text { voltage }=-0.28 \mathrm{~V} \\ D. Nothing can be concluded about K from Ecell. What factors cause changes between the liquid and gas state? E) Q is the same as Keq when a reaction is at equilibrium. C) N2 (g) + 2O2 (g) 2NO2 (g) D. 0.087 E) only reactants are present. Zimbabwe. D) a decrease in the total volume of the reaction vessel (T constant) From Midterm 3: - A gas can be converted into a liquid by increasing the pressure of a gas sample. 3.48 J/(g C) Use the following data: The value of pH is somewhat higher than 2.13. A. F2 2SO3 (g) 2SO2 (g) + O2 (g) 380) A. What is the rate constant, k, for this reaction in units of L mol-1 s-1. He(g) E. The value of pH is 2.13. Q: How much heat is produced by the complete reaction of 4.05 kg of nitromethane? The amount of 2.62 mol of a sugar is added to 1.64 kg of pure water at standard pressure. Q: Pb2+(aq)+Mg(s)Pb(s)+Mg2+(aq). 960) C) The equilibrium partial pressure of Br2 will be greater than 1.00 atm. United Kingdom, (+ 82) Determine the value of the missing equilibrium constant. Oman, (+ How can I download the CBSE MCQs in PDF Format for free? For benzoic acid, Ka=6.5105. After a sufficiently long time, [A] will approach zero, regardless of the values of k and k'. A. So Kp = (PH2) x (PI2) / PHI^2 P = partial pressure B) 2500 The vapor pressure of a certain sample has been measured at two different temperatures and the results are P1 = 160 kPa at T1 = 240 K and P2 = 840 kPa at T2 = 270 K. Determine the molar vaporization enthalpy, Hvap, from these results. 355) Oman, (+ [The decomposition of SO2Cl2 is first order in SO2Cl2 and has a rate constant of 1.46104 s1 at a certain temperature] 27) D) [SO3]2 / [SO2]2[O2]2 B. A) products predominate Arsenic acid (H3AsO4) is a polyprotic acid with Ka1 = 5.510-3, Ka2 = 1.710-7, and Ka3 = 5.110-12. A. E. 48.1 J, [A 100-W lightbulb is placed in a cylinder equipped with a moveable piston. 41) - A liquid can be converted to a gas by heating. 263) What happens to the vapor pressure of a substance when the temperature is increased? What is the best strategy while answering the Multiple Choice Questions for exams? Consider an acetate buffer that is a mixture of 0.20 M acetic acid and 0.20 M sodium acetate. 2CH3NO2(l)+3/2O2(g)2CO2(g)+3H2O(l)+N2(g) Hrxn = -1418 kJ] B. a. NCERT CBSE KVS Class 12 Chemistry MCQs will assist the children with reinforcing ideas and further develop marks in tests and tests. 12.30 D. 32.2 kJ mol-1 A. 49) 31) Calculate the equilibrium constant for the following reaction at 25C: Careful quan titative dehydration experiments [17] show that at 173 K each protonated form o f the anion has a distinct resonance, see Figure 8 .