Description : The equation, Cp- Cv = R, is true for __________ gas. (A) No (B) Any real (C) Only ideal (D) Both (B) and (C)
Last Answer : (C) Only ideal
Description : PVγ = Constant (where, γ = Cp/Cv) is valid for a/an __________ process. (A) Isothermal (B) Isentropic (C) Isobaric (D) Adiabatic
Last Answer : (D) Adiabatic
Description : y = specific heat ratio of an ideal gas is equal to (A) Cp/Cv (B) Cp/(CP-R) (C) 1 + (R/CV) (D) All (A), (B) and (C)
Last Answer : D) All (A), (B) and (C)
Description : Equal volumes of two monoatomic gases, A and B, at same temperature and pressure are mixed. The ratio of specific heats (Cp /Cv ) of the mixture will be (1) 1.67 (2) 0.83 (3) 1.50 (4) 3.3
Last Answer : (1) 1.67
Description : The two specific heats of gases are related by : (1) Cp + Cv = RJ (2) Cp –Cv = R/J (3) Cp – Cv = RJ (4) Cp /Cv = R
Last Answer : Cp –Cv = R/J
Description : Air enters an adiabatic compressor at 300K. The exit temperature for a compression ratio of 3, assuming air to be an ideal gas (Y = Cp/Cv = 7/5) and the process to be reversible, is (A) 300 × (32/7) (B) 300 × (33/5) (C) 300 × (333/7) (D) 300 × (35/7)
Last Answer : A) 300 × (32/7)
Description : The heat supplied to the gaS at constant volume is (where m = Mass of gas, cv = Specific heat at constant volume, cp = Specific heat at constant pressure, T2 – T1 = Rise in temperature, and R = Gas constant) A. mR(T2 – T1) B. mcv(T2 – T1) C. mcp(T2 – T1) D. mcp(T2 + T1)
Last Answer : Answer: B
Description : The value of Cp & Cv respectively for monatomic gases in Kcal/kg Mole.°K are (A) 5 & 3 (B) 3.987 & 1.987 (C) 1.987 & 0.66 (D) 0.66 & 1.987
Last Answer : A) 5 & 3
Description : The value of y = cp/cv. at < 500°C for air & most common gases can be safely assumed to be (A) 0.8 (B) 1 (C) 1.4 (D) 1.8
Last Answer : Option C
Description : In a P-V diagram (for an ideal gas), an isothermal curve will coincide within adiabatic curve (through a point), when (A) Cp < Cv (B) Cp = Cv (C) Cp > Cv (D) C ≥ Cv
Last Answer : (B) Cp = Cv
Description : On a P-V diagram of an ideal gas, suppose a reversible adiabatic line intersects a reversible isothermal line at point A. Then at a point A, the slope of the reversible adiabatic line (∂P/∂V)s and the slope of the reversible isothermal line ... Y (C) (∂P/∂V)S = y(∂P/∂V)T (D) (∂P/∂V)S = 1/y(∂P/∂V)T
Last Answer : (C) (∂P/∂V)S = y(∂P/∂V)T
Description : For perfect gas a. cp – cv = R b. cp + cv = R c. cp / cv = R d. cp X cv = R Where cp & cv are specific heats at constant pressure and volume.
Last Answer : ANSWER a. CP – CV = R
Description : Velocity of a gas in sound is not proportional to (where, T = Absolute temperature of the gas. P = Absolute pressure of the gas. y = Ratio of specific heats (Cp/Cv) ρ = specific weight of the gas) (A) √T (B) 1/√P (C) √y (D) 1/√ρ
Last Answer : (B) 1/√P
Description : The expression for entropy change, ΔS = n Cp. ln (T2/T1), is valid for the __________ of a substance. (A) Simultaneous pressure & temperature change (B) Heating (C) Cooling (D) Both (B) and (C)
Last Answer : (D) Both (B) and (C)
Description : The value of specific heat at constant pressure (cp) is __________ that of at constant volume (cv). A. less than B. equal to C. more than
Last Answer : Answer: C
Description : One kg of gas occupying 0.1m^3 at pressure of 14 bar is expanded at constant pressure to 0.2m^3. Determine an initial and final temperature of gas. Take Cp=1.008KJ/KgK, Cv =0.72KJ/KgK.
Last Answer : V1=0.1m^3 V2=0.2 m^3 P1=P2=14 bar Cp=1.008 KJ/KgK Cv=0.72 KJ/KgK R=Cp-Cv R=1.008-0.72 R=0.288KJ/KgK Characteristic gas equation, P1V1=mRT1 14*10^5*0.1=1*288*T1 T1=486.11K For constant pressure process, V1/T1=V2/T2 0.1/486.11=0.2/T2 T2=972.22K
Description : In the equation, PVn = constant, if the value of n is in between 1 and y (i.e. Cp/Cv), then it represents a reversible __________ process. (A) Isometric (B) Polytropic (C) Isentropic (D) Isobaric
Last Answer : (B) Polytropic
Description : In the equation PVn = constant, if the value of n = y = Cp/Cv, then it represents a reversible __________ process. (A) Isothermal (B) Adiabatic (C) Isentropic (D) Polytropic
Last Answer : (C) Isentropic
Description : (1/V) (∂V/∂T)Pis the mathematical expression (A) Joule-Thomson co-efficient (B) Specific heat at constant pressure (Cp) (C) co-efficient of thermal expansion (D) Specific heat at constant volume (CV)
Last Answer : (C) co-efficient of thermal expansion
Description : For a constant pressure reversible process, the enthalpy change (ΔH) of the system is (A) Cv.dT (B) Cp.dT (C) ∫ Cp.dT (D) ∫ Cv.dT
Last Answer : (C) ∫ Cp.dT
Description : (∂T/∂P)H is the mathematical expression for (A) Specific heat at constant pressure (Cp) (B) Specific heat at constant volume (Cv) (C) Joule-Thompson co-efficient (D) None of these
Last Answer : (C) Joule-Thompson co-efficient
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 : The ratio of specific heat at constant pressure (Cp) and specific heat at constant volume (cv) is A. equal to one B. less than one C. greater than one D. none of these
Description : Calculate the recoverable waste heat (Q, in kCal/hour) from flue gases using the followingparameters: V (flow rate of the substance) 2000 m3/hr r (density of the flue gas): 0.9 kg/m3 Cp (specific heat ... (temperature difference): 120 oC h (recovery factor): 50% a. 21600 b. 43200 c. 25600 d. 34000
Last Answer : 21600
Description : Cp /Cv is termed as (A) Adiabatic constant (B) Mach number (C) Weber number (D) Prandtl number
Last Answer : (A) Adiabatic constan
Description : In case of compression of one kg of air, the work done will be the least, when the value of polytropic index 'n' is (A) 1 (B) 1.4 (C) 1.5 (D) Y = Cp/Cv
Last Answer : A) 1
Description : For an ideal gas, Cp- Cvis (A) R (B) -R (C) 0 (D) (3/2) R
Last Answer : (A) R
Description : Fugacity and pressure are numerically not equal for the gases (A) At low temperature and high pressure (B) At standard state (C) Both (A) and (B) (D) In ideal state
Last Answer : (C) Both (A) and (B)
Description : . The entropy change in a reversible isothermal process, when an ideal gas expands to four times its initial volume is (A) R loge 4 (B) R log10 4 (C) Cv log10 4 (D) Cv loge 4
Last Answer : (A) R loge 4
Description : Give relation between Cp and Cv.
Last Answer : Ans. Cp – Cv = R
Description : The gas constant is equal to a. Cp – Cv b. Cp + Cv c. Cp – Cv + k d. None of the above
Last Answer : Cp – Cv
Description : Characteristic gas constant of a gas is equal to (a) C/Cv (b) Cv/Cp (c) Cp – Cv (d) Cp + Cv (e) Cp x Cv
Last Answer : Answer : c
Description : General gas equation is (a) PV=nRT (b) PV=mRT (d) PV = C (c) PV=KiRT (e) Cp-Cv = Wj
Last Answer : Answer : b
Description : Pick out the wrong statement. (A) Cp of monatomic gases such as metallic vapor is about 5 kcal/kg.atom (B) The heat capacity of solid inorganic substance is exactly equal to the ... isolated system (D) At absolute zero temperature, the heat capacity for many pure crystalline substances is zero
Last Answer : (C) There is an increase in entropy, when a spontaneous change occurs in an isolated system
Description : Heat transfer co-efficient (h) for a fluid flowing inside a clean pipe is given by h = 0.023 (K/D) (DVρ/µ) 0.8 (CP .µ/k) 0.4 . This is valid for the value of NRe equal to (A) < 2100 (B) 2100-4000 (C) > 4000 (D) > 10000
Last Answer : (D) > 10000
Description : Under which of the following conditions does the behavior of a real gas resemble that of an ideal gas? Is it: w) under all conditions of temperature and pressure x) only at very high pressure ... when the gas is near condensation z) only at low densities when the molecules are relatively far apart
Last Answer : ANSWER: Z -- ONLY AT LOW DENSITIES WHEN THE MOLECULES ARE RELATIVELY FAR APART
Description : Pick out the wrong statement. (A) The mole fraction of solute is directly proportional to the molality of a 'dilute' solution (B) For a non-reacting binary mixture of ideal gases, the partial ... at all temperature (D) The relative volatility of a binary mixture at the Azeotropic composition is 1
Last Answer : (C) Azeotropes obey Raoult's law at all temperature
Description : Compressibility factor (i.e., the ratio of actual volume of gas to the volume predicted by ideal gas law) for all gases are (A) Always greater than one (B) Same at the same reduced temperature (C) Same at the same reduced pressure (D) Both (B) & (C)
Last Answer : (D) Both (B) & (C)
Description : A certain gas, with cp = 0.529Btu/ lb. °Rand R = 96.2ft.lb/lb. °R, expands from 5 cu ft and 80°F to 15 cu ft while the pressure remains constant at 15.5psia. Compute for T2. a.1520°R b. 1620°R c. 1720°R d. 1820°R formula: T2= T1V2/V1
Last Answer : 1620°R
Description : A perfect gas has a value of R= 319.2 J/ kf.K and k= 1.26. If 120 kJ are added to 2.27 kf\g of this gas at constant pressure when the initial temp is 32.2°C? Find T2. a. 339.4 K b. 449.4 K c. 559.4K d. 669.4K formula: cp = kR/ k-1 Q= mcp(T2-T1)
Last Answer : 339.4 K
Description : A certain gas with cp = 0.529Btu/lb°R and R = 96.2ft/lbºR expands from 5 ft and 80ºF to 15 ft while the pressure remains constant at 15.5 psia. a. T2=1.620ºR, ∫H = 122.83 Btu b. T2 = 2°R, ∫H = 122.83 Btu c. ... , ∫H = 122.83 Btu d. T2 = 1°R, ∫H = 122.83 Btu T2= V2(t2)/V1 and ∫H = mcp (T2-T1)
Last Answer : T2=1.620ºR, ∫H = 122.83 Btu
Description : A certain gas, with cp = 0.529Btu/lb.°R and R = 96.2 ft.lb/lb.°R, expands from 5 cu ft and 80°F to 15 cu ft while the pressure remains constant at 15.5 psia. Compute for T2. (Formula: T2= T1V2/V1) a. 460°R b. 270°R c. 1620 °R d. None of the above
Last Answer : 1620 °R
Description : Cp of a gas at its critical temperature and pressure (A) Becomes zero (B) Becomes infinity (C) Equals 1 kcal/kmol °K (D) Equals 0.24 kcal/kmol °K
Last Answer : (B) Becomes infinity
Description : Mercury is an ideal barometric fluid mainly due to its (A) High density (B) Low compressibility (C) Low capillary action (D) Very low vapor pressure
Last Answer : (D) Very low vapor pressure
Description : Pick out the wrong statement. (A) A particular chemical reaction is more temperature sensitive at low temperatures (B) A very high value of equilibrium constant, K (K >> 1) indicates that the ... ) Non-ideal flow takes place in reactors due to recycling, channeling or by creation of stagnant regions
Last Answer : (C) The intercept of the Arrhenius plot is called the 'activation energy
Description : The internal energy of a gas obeying P (V - b) RT (where, b is a positive constant and has a constant Cv ), depends upon its (A) Pressure (B) Volume (C) Temperature (D) All (A), (B) & (C)
Last Answer : (C) Temperature
Description : Pick out the wrong statement. (A) A slight haze at the top of chimney indicates good combustion in the furnace (B) A bag filter incurs very small pressure drop and is very efficient for ... dust collection equipment for removal of submicronic dust particles present in flue gas (D) None of these
Last Answer : (B) A bag filter incurs very small pressure drop and is very efficient for removal of submicronic dust particles from flue gases at very high temperature
Description : Two ideal gases under same pressure and temperature are allowed to mix in an isolated system. What will be the sign of entropy change?
Last Answer : Ans. Entropy change (∆S) is positive. It is because disorder or degree of freedom increases on mixing.
Description : According to Avogadro's law A. the product of the gas constant and the molecular mass of an ideal gas is constant B. the sum of partial pressure of the mixture of two gases is sum of the ... all gases, at the same temperature and pressure, contain equal number of molecules D. all of the above