HARD
Earn 100

The density of mercury at 0 °C is 13.596 g/cm3. Its density at 100 °C will be

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Important Questions on Some Basic Concepts of Chemistry

MEDIUM

The ammonia is prepared by treating ammonium sulphate with calcium hydroxide is completely used by NiCl2·6H2O to form a stable coordination compound. Assume that, both the reactions are 100% completed. If 1584 g of ammonium sulphate and 952 g of NiCl2·6H2O are used in the preparation, the combined weight (in grams) of gypsum and the nickel ammonia coordination compound produced is ____.

Atomic weights in g mol-1:

H=1; N=14 O=16; S=32 Cl=35.5; Ca=40 Ni=59

HARD
A mixture of 100 m mol of Ca(OH)2 and 2 g of sodium sulphate was dissolved in water and the volume was made up to 100 mL. What is the mass of calcium sulphate formed and the concentration of OH- in resulting solution, respectively? (Molar mass of CaOH2, Na2SO4 and CaSO4 are 74, 143  and 136 gmol-1, respectively; Ksp of CaOH2 is5.5×10-6)
HARD

Galena (an ore) is partially oxidized by passing air through it at high temperature. After some time, the passage of air is stopped, but the heating is continued in a closed furnace such that the contents undergo self-reduction. The weight (in kg) of Pb produced per kg of O2 consumed is ____. (Atomic weights in g mol-1: O=16, S=32, Pb=207)

Give the answer to the nearest integer value.

MEDIUM

In the following reaction:

A+2B+3CAB2C3
6.0 g of A, 6.0×1023  atoms of B and 0.036 mol of C reacted and formed 4.8 g of compound AB2C3. If the atomic mass of A  and C are 60 and 80 amu, respectively. What is the atomic mass of B in amu? (Avogadro number=6×1023)

EASY
What is the mass of the precipitate formed when 50 mL of 16.9% solution of AgNO3 is mixed with 50 mL of 5.8% NaCl solution?

(Ag = 107.8, N = 14, O = 16, Na = 23, Cl = 35.5)
EASY
For the following reaction, the mass of water produced from 445 g  of C57H110O6 is: 2 C57H110O6s+163O2g114 CO2g+110H2Ol
HARD
At 300 K and 1 atm, 15 mL of a gaseous hydrocarbon requires 375 mL air containing 20% O2 by volume, for complete combustion. After combustion, the gases occupy 345 mL. Assuming that the water formed is in liquid form and the volumes were measured at the same temperature and pressure, the formula of the hydrocarbon is:
(Assume complete combustion of reactant)
MEDIUM
What is the density of water vapour at boiling point of water?
HARD
A hot air balloon with a payload rises in the air. Assume that the balloon is spherical in shape with diameter of 11.7 m and the mass of the ballon and the payload (without the hot air inside) is 210 kg Temperature and pressure of outside air are 27°C and 1 atm =105 N/m2, respectively. Molar mass of dry air is 30 g. The temperature of the hot air inside is close to [The gas constant, R=831JK-1 mol-1 ]
 
EASY
1 gram of a carbonate M2CO3 on treatment with excess HCl produces 0.01186 moles of CO2 . The molar mass of M2CO3 in  gmol-1 is:
EASY

The temperature of an object is 60°C. Its value in Fahrenheit scale is

EASY
What is the quantity of hydrogen gas liberated when 46 g sodium reacts with excess ethanol? (Given Atomic mass of Na = 23 g)
MEDIUM
20.0 g of a magnesium carbonate sample decomposes on heating to give carbon dioxide and 8.0 g magnesium oxide. What will be the percentage purity of magnesium carbonate in the sample?

(Atomic weight: Mg = 24)
MEDIUM
Excess of NaOH (aq) was added to 100 mL of FeCl3 aq resulting into 2.14 g of FeOH3. The molarity of FeCl3aq is:

(Given the molar mass of Fe=56 g mol-1 and molar mass of Cl=35.5 g mol-1)
MEDIUM
5 L of an alkane requires 25 L of oxygen for its complete combustion. If all volumes are measured at constant temperature and pressure, the alkane is
MEDIUM
The amount of arsenic pentasulphide that can be obtained when 35.5 g arsenic acid is treated with excess H2S in the presence of conc. HCl (assuming 100% conversion) is
MEDIUM
The molecular formula of a commercial resin used for exchanging ions in water softening is C8H7SO3Na molecular weight=206. What would be the maximum uptake of Ca2+ ions by the resin if expressed in mol per gm?
HARD
0.27 g of a long chain fatty acid was dissolved in 100 cm3 of hexane. 10 mL  of this solution was added dropwise to the surface of water in a round watch glass. Hexane evaporates and a monolayer is formed. The distance from edge to centre of the watch glass is 10 cm . What is the height of the monolayer?
[Density of fatty acid =0.9 g cm-3;π=3]