IIT-JEE Practise paper-12 [Test]

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Muggu

IIT-JEE Practise paper-12

A test by Muggu.

Test Questions

Question

The energy of an electron of 2p_y

orbital is;

Answers

Correct	Answer Text
	equal to 2s orbital
	same as that of and orbitals
	greater than orbital
	less than orbital

Question

Which transition of electron in the hydrogen atom emits maximum energy;

Answers

Correct	Answer Text
	$2 \rightarrow 1$
	$4 \rightarrow 3$
	$3 \rightarrow 2$
	$1 \rightarrow 4$

Question

The equilibrium constant for the reaction $Br_2 \leftrightharpoons 2Br$ a 500 K and 700 K are $1*10^{-10}$ and $1*10^{-5}$ respectively. The reaction is-

Answers

Correct	Answer Text
	slow
	fast
	endothermic
	exothermic

Question

K_c for $A+B \leftrightharpoons C + D$ is 10 at 25^0C . If a container contains 1, 2, 3 and 4 moles of A, B, C and D respectively at 25^0C , the reaction shall

Answers

Correct	Answer Text
	be at equilibrium
	proceed from left to right
	not occur
	proceed from right to left

Question

Answer the following 3 questions on the basis of the given below paragraph.

The size of the nucleus of an atom is very small since its radius is nearly $10^{-15}$ m. The nucleus comprised mainly of protons and neutrons is quite often stable despite the very strong repulsive forces between the protons. The neutrons and protons, collectively called nucleons, are held together by very strong and short range forces, called nuclear forces. Nuclear forces are nearly $10^{21}$ times stronger than electrostatic forces. These forces come into play by very rapid exchange of nuclear particles, called $\pi$ -mesons.

$proton \leftrightharpoons neutron + \pi^+$

$proton + \pi^- \leftrightharpoons neutron$

The binding forces between unlike nucleons (p and n) are explained by the oscillation of a charged pi meson ( $\pi^+$ and $\pi^-$ ). Binding forces between like nucleons (p-p or n-n) result from the exchange of neutral mesons ( $\pi^0$ ).

The stability of nucleus very much depends on the ratio of neutrons to protons (n/p ratio). This ratio for stable nuclei is close to unity for lighter elements whereas for heavier elements it ranges between 1–1.5. If n/p ratio is either too high or too low, the nucleus of such elements are expected to be unstable in nature. In order to acquire stability they emit $\alpha$ , $\beta$ or some other particles and thus show the radioactivity.

In radioactive disintegration the daughter nuclei have different atomic number than the parent nulei. The nature of emitted particle ( $\alpha$ or $\beta$ ) depends on the n/p ratio of the parent nuclei and so also the atomic number of daughter nuclei. Thus , daughter nuclei find different position in the periodic table than those of parent elements.

Which of the following particles is most likely to be emitted by Na-24?

Answers

Correct	Answer Text
	$^0_{-1}e$
	$^0_{+1}e$

Question

The particle which is most likely to be emitted by C-11 is;

Answers

Correct	Answer Text
	$_{-1}e^0$

	$_{+1}e^0$

Question

U-238 has the;

Answers

Correct	Answer Text
	none of these
	$\beta$ -rays activity
	positron activity
	$\alpha$ -rays activity

Question

In each of the following 3 questions, a statement of Assertion (A) is given and a corresponding statement of Reason (R) is given just below it. Of the statement, mark the correct answer as;

Assertion: For n=3, l may be 0, 1 and 2 and m may be $0; 0\pm1$ ; $0, \pm 1$ and $0\pm 2$

Reason: For each value of n, there are 0 to (n–1) possible values of; and for each value of l, there are 0 to $0\pm l$ values of m.

Answers

Correct	Answer Text
	A is true but R is false
	A is false but R is true
	both A and R are true but R is not the correct explanation of A
	both A and R are true and R is the correct explanation of A

Question

Assertion: The electronic configuration of nitrogen atom is represented as:
Reason: : The electronic configuration of the ground state of an atom is the one which has the greatest multiplicity.

Answers

Correct	Answer Text
	A is false but R is true
	both A and R are true and R is the correct explanation of A
	A is true but R is false
	both A and R are true but R is not the correct explanation of A

Question

Assertion: A catalyst does not alter the equilibrium constant of a reaction.

Reason: The catalyst forms a complex with the reactants and provides an alternate path with lower energy of in activation for the reaction. The forward and reverse reactions are affected to the same extent.

Answers

Correct	Answer Text
	both A and R are true but R is not the correct explanation of A
	A is true but R is false
	both A and R are true and R is the correct explanation of A
	A is false but R is true