Class 11th

An equilibrium mixture contains 2.0 moles of A(g) and 4.0 moles of B(g). Now, 2.0 moles of A(g) is added in this equilibrium mixture and the system is allowed to re-achieve equilibrium at constant volume and temperature. Now, the volume of system is doubled at constant temperature. What should be the moles of B(g) at new equilibrium? The reaction involved is

$A\left(g\right)\stackrel{}{?}2B\left(g\right)$ .

The compressibility factor of a Vanderwaal gas is 0.5 at $27°C$  and 24 atm. The value of Vanderwaal constant 'a' (in atm-L²/mol²) is (b = 0.10 L/mol, R = 0.08 L-atm/K-mol)

Consider the following reactions of 1A metals.

M + $\left(x+y\right)N{H}_3$ $\stackrel{}{\to }{\left[M{\left(N{H}_3\right)}_x\right]}^{+}+{\left[e{\left(N{H}_3\right)}_y\right]}^{-}$  

$M_{\left(am\right)}^{+}+e^{-}+N{H}_3\left(\mathcal{l}\right)\stackrel{}{\to }MN{H}_{2\left(am\right)}+\frac{1}{2}{H}_2\left(g\right)$

Which of the following statement is

INCORRECT?

The sum of “number off filled orbitals” and “number of vacant orbitals” upto valence shell of Fe is

The new white belt of a long horizontal conveyor is moving with a constant speed v = 3.0m/s. A small block of carbon is placed on the belt with zero initial velocity relative to the ground. The block will slip a bit before moving with the belt, leaving a black mark on the belt (figure). How long is that mark (in m) if the coefficient of kinetic friction between the carbon block and the belt is 0.20 and the coefficient of static friction is 0.30?

A calorimeter consists of 400g of water at $24°C.$ A 500g piece of copper at $100°C$ is thrown into the water and the equilibrium temperature is found to be $36.5°C.$  What is the molar heat capacity of copper in cal/mol k, given that 1 mol of copper has a mass of 63.5g? Neglect the heat capacity of the container.

A small elastic ball of mass m is placed at the apex of a $45°$  inclined plane as shown in the figure below. The ball is allowed to slip without friction down the plane (along the dotted line), hit the ground (as shown) and bounce along it. If the height of the inclined plane is h and the coefficient of restitution between the ball and the ground is 0.5, then the distance AB, as marked on the figure, will be N * h, where N is

A wave given by equation y = 1mm sin $\left(\frac{nx}{30}-5nt\right)$  is produced in a string 100m long of mass 1 kg. What is the tension (in N) in string? x is in m & t in sec.

A plastic ball is rising in water with terminal speed v. If we use a different plastic whose density is double that of the original ball but still less that density of water, keeping the radius same, the terminal speed would be: