Acetone reacts with iodine (I2) to form iodoform in the presence of A)CaCO3 B)NaOH C)KOH D)MgCO3
Answer: b) NaOH Explanation Acetone has a chemical formula (CH3)2CO . It is also known as propanone or dimethyl ketone... View Article
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Which one of the following reactions of Xenon compounds is not feasible? (A) XeO3 + 6HF → XeF6 + 3H2O (B) 3XeF4 + 6H2O → 2Xe + XeO3 + 12HF + 1.5O2 (C) 2XeF2 + 2H2O→ 2Xe + 4HF + O2 (D) XeF6 + RbF → Rb[XeF7]
Answer: (A) Explanation Xenon is an atom with the atomic number 54 and the symbol Xe in the modern periodic... View Article
Isotonic solutions are solutions having the same? (A) Surface tension (B) Vapour pressure (C) Osmotic pressure (D) Viscosity
Answer: (C) Explanation Isotonic solutions, in general, are those that have equal concentrations of impermeable solutes on both sides of... View Article
Sulphide ore among the following is a) Al, Hg, Pb, F b) Fe, Zn, Pb c)Hg, Pb, Na d) F, Ca, Cu, Mg
Answer: (b) Explanation Sulphide ores are mostly made up of sulphide ions. They are incredibly cost-effective and simple to remove... View Article
In a cubic lattice, the closed packed structure of mixed oxides of the lattice is made up of oxide ions, one eight of the tetrahedral voids by divalent ions (A2+) while one half of the octahedral voids are occupied by trivalent ions (B3+). What is the formula of the oxides?
One eight of the tetrahedral voids by divalent ions (A2+). One half of the octahedral voids are made up by... View Article
why is lithium the strongest reducing agent
Answer: Large amount of hydration energy makes it the strongest reducing agent inspite of its highest ionisation enthalpy. Explanation The... View Article
A cylinder contains hydrogen gas at pressure of 249kPa and temperature 27degreeC. Its density is : (R=8.3J mol−1K−1)
We know that PV = nRT ∴ PV = (Mm)RT PM = m/VRT ρ = PM/RT ρ = 249 ×... View Article
The number of tetrahedral and octahedral voids in FCC unit cells are respectively.
The face-centered cubic unit cell is known to include atoms in both the corners and the centre of the cube.... View Article
n identical cubes each of mass m and edge L are lying on a floor. If the cubes are to be arranged as one over the other in a vertical stack, the work to be done is:
The potential energy U of a body of mass m at a height h above some reference point is given... View Article
Consider a wedge of mass 2m and a cube of mass m . Between the cube and wedge, there is no friction. The minimum coefficient of friction between the wedge and the ground so that the wedge doesn’t move is
The coefficient of friction is represented as μ. The frictional force is divided into horizontal and vertical components. Those are... View Article
The breakdown in a reverse biased p-n junction diode is more likely to occur due to.
If the doping concentration is low, the breakdown in a reverse biassed PN junction diode will most likely occur due... View Article
A ring rotates about the z axis as shown in the figure. The plane of rotation is x-y. At a certain instant, the acceleration of a particle P is (6hat{i}−8hat{j})ms−2 . Find the angular acceleration of the ring and the angular velocity at that instant. Radius of the ring is 2m
Tangential acceleration refers to the force acting along the tangent. This is commonly referred to as at. The magnitude is... View Article
What is equivalent weight in chemistry?
Equivalent Weight The amount of substances that completely react with each other in the reaction is called equivalent weight in... View Article
An aqueous solution of methanol in water has vapour pressure: A) Equal to that of water B) Equal to that of methanol C) More than that of water D) Less than that of water
Raoult’s Law states that in a solution, the partial vapour pressure of each volatile compound is directly proportional to its... View Article
The resistance in the two arms of the meter bridge are 5 Ω and R Ω , respectively. When the resistance R is shunted with an equal resistance, the new balance point is at1.6l1. The resistance R is
Known resistance, R = 5Ω Initial unknown resistance = RΩ New balancing point L = 1.6l1 We have, R/L =... View Article
A particle of charge q and mass m moves in a circular orbit of radius r with angular speed ω. The ratio of the magnitude of its magnetic moment to that of its angular momentum depends on
The angular momentum L of the particle is given by L=mr2w where w=2πn. ∴ Frequency n = w/2π Further i... View Article
For an object projected from the ground with speed u, horizontal range is two times the maximum height attained by it. The horizontal range of the object is:
Here, we will use the relation between the horizontal range R, acceleration due to gravity g, initial speed u and... View Article
pH of a saturated solution of Ba(OH)2 is 12 . The value of Ksp is:
We know that pH for barium hydroxide is 12 . So, pOH = 14−pH pOH = 14−12 pOH = 2... View Article
A boat, which has a speed of 5km/h in still water, crosses a river of width 1km along the shortest path possible in 15 minutes. Find the velocity of the river?
Speed in still water is 5 km/h Let the velocity of the river be m km/h Width of the river... View Article
Which hydrogen halide is most volatile?
Answer: HCl Explanation The volatility of the hydrogen halides can be compared on the basis of the size of the... View Article
