Stoichiometry Indiabix Flashcards
CaCO3 contains __________ percent of Ca by weight.
40
Solutions which distil without change in composition are called
Azeotropic
The evaporation of aqueous solution of sugar causes its molarity to
remain unchanged.
One Newton is equal to __________ dynes.
10^5
A very dilute solution is prepared by dissolving ‘x1’ mole of solute in ‘x2’ mole of a solvent. The mole fraction of solute is approximately equal to
x1/x2
The rate of material __________ is zero in case of a steady state system.
Accumulation
A metal oxide is reduced by heating it in a stream of hydrogen. After complete reduction, it is found that 3.15 gm of the oxide has yielded 1.05 gm of the metal. It may be inferred that the
equivalent weight of the metal is 4.
Molar heat capacity of water in equilibrium with ice at constant pressure is
∞
If pH value of a solution is 8, then its pOH value will be
6
Heat capacity of air can be approximately expressed as, Cp = 26.693 + 7.365 x10-3 T, where, Cp is in J/mole.K and T is in K. The heat given off by 1 mole of air when cooled at atmospheric pressure from 500°C to - 100°C is
18.11 kJ
Equal masses of CH4 and H2 are mixed in an empty container. The partial pressure of hydrogen in this container expressed as the fraction of total pressure is
8/9
If pH value of an acidic solution is decreased from 5 to 2, then the increase in its hydrogen ion concentration is __________ times.
1000
N2 content in a urea sample was found to be only 42%. What is the actual urea content of the sample ? (molecular weight of urea = 60)
90%
6 gms of magnesium (atomic weight = 24), reacts with excess of an acid, the amount of H2 produced will be _
0.5
On addition of 1 c.c. of dilute hydrochloric acid (1% concentration) to 80 c.c. of a buffer solution of pH = 4, the pH of the solution becomes
4
One mole of methane undergoes complete combustion in a stoichiometric amount of air. The reaction proceeds as CH4+ 2O2→ CO2+ 2H2O. Both the reactants and products are in gas phase. ΔH°298= - 730 kJ/mole of methane. Mole fraction of water vapour in the product gases is about
0.19
Pure aniline is evaporating through a stagnant air film of 1 mm thickness at 300 K and a total pressure of 100 KPa. The vapor pressure of aniline at 300 K is 0.1 KPa. The total molar concentration under these conditions is 40.1 mole/m3 . The diffusivity of aniline in air is 0.74xl0-5m2/s.The numerical value of mass transfer co-efficient is 7.4 x 10-3. The rate of evaporation of aniline is 2.97 x 10-4. Its units are
kmole/m2 . s
The temperature at which the second Virial co-efficient of a real gas is zero is called the
eutectic point
The net heat evolved or absorbed in a chemical process, i.e. total change in the enthalpy of the system is independent of the
number of intermediate chemical reactions involved.
1 kg of calcium carbide (CaC2) produces about 0.41 kg of acetylene gas on treatment with water. How many hours of service can be derived from 1 kg of calcium carbide in an acetylene lamp burning 35 litres of gas at NTP per hour ?
5
10
rigid vessel containing three moles of nitrogen gas at 30°C is heated to 250°C. Assume the average capacities of nitrogen to be Cp = 29.1 J/mole.°C and, Cv = 20.8 J/mole.°C. The heat required, neglecting the heat capacity of the vessel, is
19206 J
In the reaction, Ca + 2H2O = Ca(OH)2 + H2 ; what volume (c.c.) of hydrogen at STP would be liberated, when 8 gm of calcium reacts with excess water ? (atomic weight of calcium = 40)
4480
The heat evolved in the combustion of benzene is represented by the equation:
C6H6 + 7.5 O2 = 6CO2 + 3H2O, ΔH = 3264.6 kJ/kg. mole
The heat energy change, when 39 gm of C6H6 is burnt in an open container, will be __________ kJ/kgmole.
-1632.3
An aqueous solution of 2.45% by weight H2SO4 has a specific gravity of 1.011. The composition expressed in normality is
0.5055
