the correct order of bond lengths for c–c bonds in benzene, ethyne, ethene and ethane is
One sigma and one pi bond are found in alkene bonds. One sigma and one pi bond are also found... View Article
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one mole of hydrogen gas at temperature t is mixed with one mole of helium gas at temperature 2t in an isolated vessel. the equilibrium temperature of the gas mixture is
△Q = nCp△T (Cp)m = [1 x (5R/2) + (1x7R/2)]/2 = 12R/4 = 3R △Q = 2 x 3R x... View Article
a gaseous mixture of equal mass of ch4 and o2 is stored over water. if total pressure is 0.5 atm then partial pressure of dry ch4 gas is (aqueous tension = 0.2 atm)
Molecular Mass of CH4=16 Moles of CH4 = x/16 Molecular Mass of O2=32 Moles of O2 = x/32 Total moles... View Article
which among the following pairs has bleaching action due to theIRR reducing and oxidising property respectively?
SO2 and Cl2 pairs has bleaching action. Sulfur dioxide and chlorine are both effective bleaching agents. Chlorine’s bleaching action is... View Article
number of isomeric alcohol(s) with molecular formula c5h12o which will give positive iodoform test is
There are 8 alcohol possible for c5h12o molecule. They are 1-pentanol 2-pentanol 3-pentanol 2-methylbutan-1-ol 2-methylbutan-2-ol 3-methylbutan-2-ol 3-methylbutan-1-ol 2,2-dimethylpropanol A haloform... View Article
time+required+for+75%+radioactive+disintegration
1st half- Life → 50% decay 2nd half- Life → 75% decay The half-life period of the radioactive element, if... View Article
at equilibrium the rate of dissolution of a solid solute in a volatile liquid solvent is
We can say that at equilibrium, the rate of dissolution is the forward reaction and the rate of crystallisation is... View Article
if 2.8 g of a metal oxide contains 0.8 g oxygen, then the equivalent mass of the metal is
According to the law of definite proportion, a given compound always has the same proportion of constituents by weight. Case... View Article
solubility of cu(oh)2 in 0.1 m aqueous naoh solution is (ksp of cu(oh)2 = 2.2 × 10–20)
For Cu(OH)2, the expression of solubility product is: Ksp = [Cu2+][OH-]2 = (s)(2s)2 = 4s3 Substitute Ksp = 1.6 ×... View Article
the correct set of carbonate ores is (i) dolomite (ii) anglesite (iii) cuprite (iv) malachite (v) argentite (vi) siderite
Magnesite − MgCO3 Siderite − FeCO3 are the correct set of carbonate ore.
100 ml of 0.2 m alcl3 is required just to cause coagulation of 700 ml of as2s3 sol. what is the flocculation value of alcl3?
Flocculation, also known as coagulation is the process of precipitation of a colloidal solution by the addition of the excess... View Article
reema took 5 ml of lead nitrate solution in a beaker and added approximately 4 ml of potassium iodide solution to it. what would she observe?
The relation between lead nitrate and potassium iodide is an example of precipitation reaction. Pb(No3)2 + 2KI ⟶ PbI2 +... View Article
a radioactive substance has activity 2a0 at t = 0. after 3 second it has activity a0. the decay constant of the sample is
t=0 activity is N0 then after time t the activity is given as 100=1600×(1/2)^n so n=4 n=4 and t=8s we... View Article
one mole of n2o4 in a 1l flask decomposes to attain the equilibrium n2o4(g) ⇌ 2no2(g). at the equilibrium the mole fraction of n2o4 is 1 2 . then kc will be
Mole fraction of NO2=2x/(1−x+2x)=2x/(x+1)=1/2 solving, we get 4x=x+1 3x=1 x=1/3 =(4/9)/(2/3)=4X3/9X2=2/3 Therefore, 2/3 is the answer.
1 mol of ideal gas expands reversibly and isothermally from 1 l to 100 l at 300 k. the heat exchange during the process is nearly
W = −1×8.314×300×ln 20/10 W = −2494.2×(ln2−ln1) = −1728.8J = −1.73 kJ From first law of thermodynamics, ΔU=ΔH+W Since temperature... View Article
the gold number of four protective colloids a, b, c and d are 0.1, 0.25, 5 and 15 respectively. the maximum protecting power is of
Smaller the gold number, greater is the protective power. 0.25>0.1>5>15
a gas mixture consists of 2 moles of nitrogen and 4 moles of xenon at temperature t. neglecting all vibrational modes, the total internal energy of the system is
For Oxygen , no of moles n1=2 , no. Of degree of freedom per molecule, f1=5 For Argon, no.of moles... View Article
consider the ellingham diagram for zn, mg and carbon converting into theIRR corresponding oxides. at 1100ºc, which one of the following reactions is spontaneous to a maximum extent?
Any metal will reduce the oxide of other metals above it on the Ellingham diagram because the free energy difference... View Article
amount of heat evolved when 500 cm3 of 0.2 m h2so4 is mixed with 200 cm3 of 0.5 m naoh solution is
In neutralisation of 1 mole of NaOH by 1 mole HCl, heat evolved =57.3kJ To neutralise 0.04 mole of NaOH... View Article
reaction follows following rate law rate = . starting with initial conc. of one mole of a and b each, what is the time taken (in sec) for amount of a to become 0.25 mole. given ,
If the sum of all powers elevated to the concentration is zero, a reaction is said to be zero order,... View Article
