HARD
JEE Main
IMPORTANT
Earn 100

A mixture of pure K2Cr2O7 and pure KMnO4 weighing 0.561 g was treated with excess of KI in acid medium. Iodine liberated required 100 mL of 0.15 N hypo solution for exact oxidation. What is the percentage of each in the mixture? The reactions involved are:

2KMnO4+8H2SO4+10KI6K2SO4+2MnSO4+8H2O+5I2

K2Cr2O7+6KI+7H2SO44K2SO4+Cr2SO43+7H2O+3I2

I2+2Na2S2O32NaI+Na2S4O6

Important Questions on Miscellaneous Problems for Revision

MEDIUM
JEE Main
IMPORTANT
If PCl5 is heated to 250°C and allowed to reach equilibrium, 50% of PCl5 is dissociated. Calculate how many moles of Cl2 must be mixed with one mole of PCl5 to reduce the dissociation to 40%, with the volume remaining constant.
HARD
JEE Main
IMPORTANT
Given that, Kc=13.7 at 546 K for PCl5 gPCl3 g+Cl2 g. Calculate what pressure will develop in a 10 L box at equilibrium at 546 K when 1 mol of PCl5 is introduced into the empty box.
MEDIUM
JEE Main
IMPORTANT

Under what pressure must an equimolar mixture of Cl2 and PCl3 be placed at 250°C in order to obtain 80% conversion of PCl3 into PCl5? Kp for PCl3(g)+Cl2(g)PCl5(g) is 1.78.

Round off your answer up to two places of decimal.

HARD
JEE Main
IMPORTANT
If the degree of dissociation of PCl5 at a certain temperature and at 1 atm is 0.2. The pressure at which the substance will be half-dissociated at the same temperature is x × 10-4. Calculate the value of x.
HARD
JEE Main
IMPORTANT
In the dissociation of HI, it is found that 20% of the acid is dissociated when the equilibrium is reached. Calculate the pressure equilibrium constant.
HARD
JEE Main
IMPORTANT

0.45 g of an organic compound (A), on ignition, gives 0.905 g CO2 and 0.185 g H2O. 0.35 g (A) on boiling with HNO3 and adding AgNO3 solution gives 0.574 g of AgCl. The vapour density of (A) is 87.5 . (A) on hydrolysis with Ca (OH)2 yields (B), which on mild reduction gives an optically active compound (C). On heating (C) with I2 and NaOH, iodoform is produced along with (D). With HCl, (D) gives a solid, which is markedly more soluble in hot water than in cold. Identify (A), (B), (C) and (D).

Question Image

HARD
JEE Main
IMPORTANT

Two organic compounds containing C=62.1%, H=10.34%, O=27.6%, with KCN and H2SO4, gave compounds, which on hydrolysis gave two isomeric monobasic acids with molecular mass 104. Name the compounds and also the third isomer.

Question Image

HARD
JEE Main
IMPORTANT

The compound (X), with molecular formula C5H8O, does not react appreciably with Lucas reagent at room temperature, but gives a precipitate with ammonium silver nitrate. With an excess of MeMg Br, 0.42 g of (X) gives 224 mL of CH4 at STP. The treatment of (X) with H2 in the presence of Pt catalyst, followed by boiling with an excess HI, gives n-pentane. Suggest the structure for (X).