4.215 g of a metallic carbonate was heated in a hard glass tube and the CO2 evolved was found to measure 1336 ml at 27oC

The largest number of molecules is in

2.76 g of silver carbonate on being strongly heated yields a residue weighing

A gaseous mixture contains oxygen and nitrogen in the ratio of 1 : 4 by weight. Therefore the ratio of their no of molec

The total number of electrons is one molecule of carbon dioxide is

(a). 5.5 g of a mixture FeSO4.7H2O and Fe2(SO4)3.9H2O requires 5.4 ml of 0.1 N KMnO4 solution for complete oxidation. Ca

5 ml of a gas containing only carbon and hydrogen were mixed with an excess of oxygen (30 ml) and the mixture exploded b

In the analysis of 0.5 g sample feldspar, a mixture of chlorides of sodium and potassium is obtained which weighs 0.1180

The number of neutrons in dipositive zinc ion with mass number 70 is

The compound which contains both ionic and covalent bonds is

The octet rule is not valid for the molecule

Account for the following : Limit your answer to two sentences. "Atomic weights of most of the elements are fractional."

A white amorphous powder (A) on heating yields a colourless, non-combustible gas (B) and a solid (C). The latter compoun

The precipitation of second group sulphides in qualitative analysis is carried out with hydrogen sulphide in the presenc

Prove that the minimum value of $${{\left( {a + x} \right)\left( {b + x} \right)} \over {\left( {c + x} \right)}},$$ $$a

Evaluate $$\int {{{{x^2}dx} \over {{{\left( {a + bx} \right)}^2}}}} $$

Two fair dice are tossed. Let $$x$$ be the event that the first die shows an even number and $$y$$ be the event that the

Six boys and six girls sit in a row randomly. Find the probability that (i) the six girls sit together (ii) the boys a

If $$\alpha + \beta + \gamma = 2\pi ,$$ then

(a) If a circle is inscribed in a right angled triangle $$ABC$$ with the right angle at $$B$$, show that the diameter of

If $$\tan \theta = - {4 \over 3},then\sin \theta \,is\,$$

If the cube roots of unity are $$1,\,\omega ,\,{\omega ^2},$$ then the roots of the equation $${\left( {x - 1} \right)^3

If x + iy = $$\sqrt {{{a + ib} \over {c + id}}} $$, prove that $${({x^2} + {y^2})^2} = {{{a^2} + {b^2}} \over {{c^2} + {

(a) Draw the graph of $$y = {1 \over {\sqrt 2 }}\left( {cinx + \cos x} \right)$$ from $$x = - {\pi \over 2}$$ to $$x =

If $$\alpha ,\,\beta $$ are the roots of $${x^2} + px + q = 0$$ and $$\gamma ,\,\delta $$ are the roots of $${x^2} + rx

The equation x + 2y + 2z = 1 and 2x + 4y + 4z = 9 have

If x, y and z are real and different and $$\,u = {x^2} + 4{y^2} + 9{z^2} - 6yz - 3zx - 2xy$$, then u is always.

Let a > 0, b > 0 and c > 0. Then the roots of the equation $$a{x^2} + bx + c = 0$$

If $$\ell $$, m, n are real, $$\ell \ne m$$, then the roots by the equation : $$(\ell - m)\,{x^2} - 5\,(\ell + m)\,x

Given that $${C_1} + 2{C_2}x + 3{C_3}{x^2} + ......... + 2n{C_{2n}}{x^{2n - 1}} = 2n{\left( {1 + x} \right)^{2n - 1}}$$

$${}^n{C_{r - 1}} = 36,{}^n{C_r} = 84\,\,and\,\,{}^n{C_{r + 1}} = 126$$, then r is :

The harmonic mean of two numbers is 4.Their arithmetic mean $$A$$ and the geometric mean $$G$$ satisfy the relation. $$2

The points $$\left( { - a,\, - b} \right),\,\left( {0,\,0} \right),\,\left( {a,\,b} \right)$$ and $$\left( {{a^2},\,ab}

(a) Two vertices of a triangle are $$(5, -1)$$ and $$(-2, 3).$$ If the orthocentre of the triangle is the origin, find t

Find the derivative of $$$f\left( x \right) = \left\{ {\matrix{ {{{x - 1} \over {2{x^2} - 7x + 5}}} & {when\,\,x

If the bisector of the angle $$P$$ of a triangle $$PQR$$ meets $$QR$$ in $$S$$, then

(a) A balloon is observed simultaneously from three points $$A, B$$ and $$C$$ on a straight road directly beneath it. Th

The dispalcement x of particle moving in one direction, under the action of a constant force is related to the time t by

Answer the following giving reason in brief: Is the time variation of position, shown in the figure observed in nature?