The percentage of nitrogen in urea is:

In a packet of 40 pens, 12 are red. So, what % age are red pens?

Consider the following compounds, which of these will release CO₂ with 5% NaHCO₃ ?
i)
ii)
iii) 

Identify the product' Y' in the following reaction sequence:

In homogeneous catalytic reactions, there are three alternative paths A,B and C (shown in the figure) which one of the following indicates the relative ease with which the reaction can take place?

In a spontaneous adsorption process

Graph between log and log P is a straight line at angle 0 45 with intercept OA as shown Hence , at a pressure of 2 atm is

If and   then

Assertion : For the volume of the parallel piped formed by vectors and is maximum (The vectors form a right-handed system)
Reason: The volume of the parallel piped having three coterminous edges and

For such questions, we should know the formula of a parallelepiped. We should also know how to take a scalar product.

Assertion (A): Let . If such that is collinear with and is perpendicular to is possible, then .
Reason (R): If and are non-zero, non-collinear vectors, then can be expressed as where is collinear with and is perpendicular to

Statement If are distinct non-negative numbers and the vectors â and are coplanar then is arithmetic mean of and .
Statement -2: Parallel vectors have proportional direction ratios.

If and is a vector satisfying .
Assertion can be expressed in terms of and .
Reason

If are non-zero vectors such that then
Assertion : Least value of is
Reason (R): The expression is least when magnitude of is

Statement- 1: If and and , then there exist real numbers , such that
Statement- 2: are four vectors in a 3 - dimensional space. If are non-coplanar, then there exist real numbers such that

Statement- :If are non-collinear points. Then every point in the plane of , can be expressed in the form
Statement- :The condition for coplanarity of four points is that there exists scalars not all zeros such that   where .

Assertion (A): The number of vectors of unit length and perpendicular to both the vectors. and is zero Reason
(R): and are two non-zero and non-parallel vectors it is true that is perpendicular to the plane containing and