Class 11th

Let the lengths of intercepts on x-axis and y-axis made by the circle x² + y² + ax + 2ay + c = 0, (a < 0) be 22 and 25, respectively. Then the shortest distance from origin to a tangent to this circle which is perpendicular to the line x + 2y = 0, is equal to :

For the reaction A(g)          B(g) at 495 K, ΔrGo = -9.478kJ/mol. If we start the reaction in a closed container at 495 K with 22 millimoles of A, the amount of B in the equilibrium mixture is __________ millimoles

(Round off to the nearest Integer). [R=8.314 J/mol K; ln 10 = 2.303]

Complete combustion of 750g of an organic compound provides 420 g of CO2 and 210 g of H2O.

The percentage composition of carbon and hydrogen in organic compound is 15.3 and _________ respectively. (Round off to the nearest Integer).

2MnO^-4   + bC2O^2-4 + cH⁺               xMn²⁺ + yCO2 + zH2O

If the above equation is balanced with integer coefficients, the value of c is_________.

(Round off to the nearest Integer).

Given below are two statements:

Statement I : H2O2 can act as both oxidizing and reducing agent in basic medium.

Statement II: In the hydrogen economy, the energy is transmitted in the form of dihydrogen.

In the light of the above statements, choose the correct answer from the options given below:

A group 15 element, which is a metal and forms a hydride with strongest reducing power among group 15 hydrides. The element is:

Consider a rectangle ABCD having 5,7,6,9 points in the interior of the segments AB, CD, BC, DA respectively. Let α be the number of triangles having these points from different sides as vertices and β be the number of quadrilaterals having these points from different sides as vertices. Then (β-α) is equal to :

Given below are two statements:

Statement I : Both CaCl2.6H2O and MgCl2.8H2O undergo dehydration on heating.

Statement II : BeO is amphoteric whereas the oxides of other elements in the same

group are acidic.

In the light of the above statements, choose the correct answer from the options given below:

The type of pollution that gets increased during the day time and in the presence of O3 is: