|1 Crore+ students have signed up on EduRev. Have you?|
What amount of solid sodium acetate be added into 1 litre of the 0.1 M CH3COOH solution so that the resulting solution has pH almost equal to pKa (CH3COOH) = 4.74
Liquid ammonia ionizes to a slight extent. At –50°C, its ion product is How many amide ions, NH-2are present per mm3 of pure liquid ammonia?
For preparing a buffer solution of pH 6 by mixing sodium acetate and acetic acid, the ratio of concentration of salt and acid (Ka = 10–5) should be:
The number of degrees of freedom in the homogenous liquid region of a two component system with a eutectic point, at one atmosphere pressure is:
The maximum number of triple point(s) occuring in one component sulfur system are:
Consider the following equilibrium in a closed vessel . At a fixed temperature if the volume of the reaction vessel is halved, which of the following statements holds true regarding the equilibrium constant (Kp) and the degree of dissociation (α) of N2O4?
Under conditions of constant temperature and pressure when a system is in equilibrium which of the following quantities is at a minimum:
C is correct.
For a system with controlled constant temperature and pressure, G is minimum at thermodynamic equilibrium.
Based upon the following hypothetical equilibrium at 273 K
Which is the most effective dehydrating agent at 273 K (Aqueous tension at 273 K = 6.0 × 10–3atm)
An equilibrium system for the reaction between hydrogen and iodine to give hydrogen iodine at 765 K in a 5 liter volume contains 0.4 mole of hydrogen, 0.4 mole of iodine and 2.4 moles of hydrogen iodide. The equilibrium constant for the reaction is:
To a 50 ml of 0.1 M HCl solution, 10 ml of 0.1 M NaOH is added and the resulting solution is diluted to 100 ml. What is change in pH of the HCl solution?
To a 100 ml solution of 0.1 M CH3COONa and 0.1 M CH3COOH, 0.4 gm of solid NaOH was added. Assuming volume remains constant, calculate the change in pH value? Given that pKa(CH3COOH) = 4.74.
When equal volumes of the following solution are mixed, precipitation of AgCl (Ksp = 1.8 × 10–10) will occur only with:
How many gram of CaC2O4 will dissolve in one litre of saturated solution? Ksp of CaC2O4 is 2.5 × 10–9mol–2 and its molecular weight is 128:
Let the solubilities of AgCl in H2O, 0.01 M CaCl2; 0.01 M NaCl and 0.05 M AgNO3 be S1, S2, S3, S4 respectively. What is the correct relationship between these quantities?
Calculate the minimum mole % of CO2 in air at 1 bar which is sufficient to prevent any loss in weight of Ag2CO3 by decomposition at the same temperature:
At temperature T, a compound AB2(g) dissociates according to the reaction with degree of dissociation α, which is small compared with unity. The expression for Kp, in terms of α and the total pressure, PT is:
A reaction mixture containing H2, N2 and NH3 has partial pressures 2 atm, 1 atm and 3 atm respectively at 725 K. If the value of Kp for the reaction. is4.28 × 10–5atm–2 at 725 K, in which direction the net reaction will go:
pH of an aqueous solution of Al+3 is likely to be:
The molar solubility (in mol L–1) of a sparingly soluble salt MX4 is ‘s’. The corresponding solubility product is Ksp. s is given in terms of Ksp by the relation:
The phase diagram of a pure substance is sketched below:
The number of degrees of freedom at points P1, P2 and P3, respectively, are:
Consider a phase diagram of two component simple eutectic system. If XA = 0.8 and XB = 0.2, which of the following composition will never be observed:
The number of phases, components and degrees of freedom, when Ar is added to an equilibrium mixture of NO, O2 and NO2 in gas phase are, respectively:
A pure substance exists in several different phases A, B, C. Its partial phase diagram is shown below:
Which of the following statements is correct about the above diagram?
The lowest pressure at which the liquid phase of a pure substance can exist is known as:
The solid-liquid phase diagram for the Mg-Zn system is shown in the figure below where the vertical line at X(Mg) = 0.33 represents the formation of a congruent melting compound MgZn2.The figure is divided into seven regions depending upon the physical state of the system. The composition of the region #6 represents.
Which of the following does not represent a phase diagram?
For the reaction the degree of dissociation (α) of HI(g) is related to equilibrium constant Kp by the expression:
pH of the following solution is not affected by dilution:
When HCl(g) is passed through a saturated solution of common salt, pure NaCl is precipitated because:
Formation of Y from X is through the graph. It can be concluded:
The expression for the equilibrium constant for an ideal-gas reaction mixture is given by:
With a certain radiation (exciting) of a particular frequency, to which hydrogen atoms are exposed, the maximum number of spectral lines is obtainable in the emission is 15. The uppermost energy level to which the is excited is n =
Benzene and naphthalene form an ideal solution at room temperature. For this process, the true statement(s) is/are:
Which of the following statements are incorrect:
When baking soda is heated in a sealed tube, following equilibrium exists:
If the equilibrium pressure is 1.04 atm at 398 K, calculate the equilibrium constant for the reaction at 398 K [up to two decimal places]:
16 moles of H2 and 4 moles of N2 are sealed in a one litre vessel. The vessel is heated at a constant temperature until the equilibrium is established, it is found that the pressure in the vessel has fallen to 9/10 of its original value. Calculate KC for the reaction. [In the multiple of 10–4 up to two decimal places]:
How many milli-moles of Ca(OH)2 must be dissolved to produce 250 mL of an aqueous solution of pH 10.65, assuming complete dissociation? [up to two decimal places]
For a pure substance, lnP(solid) = –20/T + 10 and lnP(liquid) = –15/T + 2. Calculate enthalpy of fusion. [In the multiple of R]
Among CO2, Sulfur, Water, Antimony, Bismuth how many have (dp/dT)fusion is negative?
At 0°C, ∆Hfusion(ice) = 1092 Kcal/mol. The molar entropy change for melting of ice at 0°C is? (in kcal/Kmol, up to two decimal places)
Find out amount (in gram, up to first decimal place) of NH4Cl dissolved in 500 mL to have pH = 4.5. Kb for NH4OH is 1.8 × 10–5.
Calcium lactate is a salt of weak organic acid and strong base, represented as Ca(Lac)2. A saturated solution of Ca(Lac)2 contains 0.13 mole of this salt in 0.50 L solution. The pOH of this solution is 5.60. Assuming a complete dissociation of the salt, calculate Ka of lactic acid. [In the multiple of 10–4, up to first decimal place]
The self-ionization constant for pure formic acid, K = [HCOOH2+] [HCOO–] has been estimated as 10–6 at room temperature. What percentage of formic acid molecules in pure formic acid are converted to formate ion? The density of formic acid is 1.22 g/cm3. [rounded up to four decimal places]
Calculate the pH of solution obtained by mixing 10 mL of 0.1 M HCl and 40 of 0.2 M H2SO4? [up to two decimal places]
A sample of HI was found to be 22% dissociated when equilibrium was reached. What will be the degree of dissociated if hydrogen is added in the proportion of 1 mole for every mole of HI originally present, the temperature and volume of the system being kept constant: [up to two decimal places]
The pH of pure water at 25°C and 35°C are 7 and 6 respectively. Calculate the heat of formation (cal/mol, up to first decimal place) of water from H+ and OH–?
Calculate pH change when 0.01 mol CH3COONa solution is added to one litre of 0.01 CH3COOH solution. [up to two decimal places]
Ka (CH3COOH) = 1.8 × 10–5, pKa = 4.74
50 mL of 0.1 M NaOH is added to 75 mL of 0.1 M NH4Cl to make a basic buffer. If pKa of NH4+ is 9.26, Calculate pH (up to two decimal places)?
Kc for the equilibrium reaction N2O4 dissociating into 2NO2 in chloroform at 291K is 1.14. Calculate free energy change of reaction (Latm) when concentration of two gases are 0.5 mol/L each at same temp. (R = 0.082 LatmK–1mol–1, up to two decimal places)
The degree of dissociation at a certain temp of PCl5 at 2 atm is found to be 0.4. At what pressure, the degree of dissociation of PCl5 will be 0.6 at same temp: [up to two decimal places]
The vapor density of a mixture containing NO2 and N2O4 is 38.3 at 26.70C. Calculate no of moles of NO2 in 100g mixture: [up to three decimal places]
An aqueous system containing K+, Na+, Cl– what are number of components if salts are present in equal amount?
3 phases are in equilibrium for which T and P can be independently changed at constant composition. Calculate components (C):
For a pure substance, lnP(solid) = –20/T + 10 and lnP(liquid) = –15/T + 2. Calculate ratio of slope at triple point [up to two decimal places]: