Tag: look, learn and experience

Questions Related to look, learn and experience

Which of the following processes results in the formation of a new compound?

evs look, learn and experience matter: states, classification and properties study of matter general introduction: importance and scope of chemistry

  1. Dissolving common salt in water

  2. Heating water

  3. Heating platinum rod

  4. Heating iron rod

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Correct Option: A
Explanation:

Heating of any substance will give the same compound unless temperature is taken upto such high where the compound breaks down into its constituents. Dissolving common salt in water will give brine solution.

Match the column I and II and select the correct option from the codes given below:

   Column I   Column II 
 (P) Liquid  (i)  Highly compressible 
 (Q) Gas  (ii)  Definite volume 
 (R) Plasma  (iii)  Super low density 
 (S) Bose-Einstein condensate  (iv)  Super energetic  
evs look, learn and experience matter: states, classification and properties study of matter general introduction: importance and scope of chemistry

  1. (P)-(i), (Q)-(ii),(R)-(iii),(S)-(iv)

  2. (P)-(ii), (Q)-(i),(R)-(iii),(S)-(iv)

  3. (P)-(ii), (Q)-(i),(R)-(iv),(S)-(iii)

  4. (P)-(iii), (Q)-(i),(R)-(ii),(S)-(iv)

Show answer
Correct Option: C
Explanation:

(P) Liquid have a definite volume as the particles are in contact with each other.

(Q) Gas is highly compressible as there is a huge distance between the gas molecules.
(R) Plasma (fourth state of matter) is a gas that has been energized to a point that some of the $e^-$ break free from but travel with their nucleus. A spark in the gas creates plasma.
(S) Bose-Einstein Condensate is formed by cooling a gas of extremely low density. It is the fifth state of matter.

Vinegar, which is commonly used in pickle preparation is actually:

evs look, learn and experience matter: states, classification and properties study of matter general introduction: importance and scope of chemistry

  1. Ethyl alcohol

  2. Folic acid

  3. Nitric acid

  4. Acetic acid

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Correct Option: D
Explanation:
Acetic acid (vinegar) is the primary ingredient used in pickle manufacturing. After water, it makes up the bulk of the pickle liquor and contributes significantly to the flavour of the pickle giving it a sour taste.

Hence, the correct option is $D$

The reference standard used for defining atomic mass is:

evs look, learn and experience matter: states, classification and properties study of matter general introduction: importance and scope of chemistry

  1. $H-1$

  2. $C-12$

  3. $C-13$

  4. $C-14$

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Correct Option: B
Explanation:

Atomic mass is defined as a multiple of one-twelfth the mass of the carbon-12 atom.

Which of the following is a chemical compound?

evs look, learn and experience matter: states, classification and properties study of matter general introduction: importance and scope of chemistry

  1. Salt

  2. Iron

  3. Oxygen

  4. Diamond

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Correct Option: A
Explanation:

Salt like $NaCl, MgCO _3, KCl,$ etc are compounds. Iron is an element. $O _2$ is a molecule. Diamond is pure elemental carbon compressed to its crystal form.

Match the columns I, II and III and mark the appropriate choice.

Column I Column II Column III
(A) Bromine (i) Noble metal (p) Amalgam
(B) Gold (ii) Crystalline non-metal (q) $4s^{2}4p^{5}$
(C) Mercury (iii) Liquid non-metal (r) Transition metal
(D) Iodine (iv) Liquid metal (s) Violet
evs look, learn and experience matter: states, classification and properties study of matter general introduction: importance and scope of chemistry

  1. (A)$\rightarrow$(iii, q); (B)$\rightarrow$(i, r); (C)$\rightarrow$(iv, p); (D)$\rightarrow$(ii, s)

  2. (A)$\rightarrow$(ii, p); (B)$\rightarrow$(i, s); (C)$\rightarrow$(iii, q); (D)$\rightarrow$(iv, r)

  3. (A)$\rightarrow$(i, s); (B)$\rightarrow$(ii, p); (C)$\rightarrow$(iv, r); (D)$\rightarrow$(iii, q)

  4. (A)$\rightarrow$(iv, r); (B)$\rightarrow$(iii, q); (C)$\rightarrow$(ii, s); (D)$\rightarrow$(i, p)

Show answer
Correct Option: A
Explanation:
 Col I  Col II  Col III
 (A) Bromine  (iii)liquid non-metal  (q)$4s^24p^5$
 (B) Gold  (i) Noble metal  (r)Transition metal
 (C) Mercury  (iv)liquid metal  (p)Amalgam
 (D) Iodine  (ii)crystalline non-metal  (s)violet

(A)-(iii, q); (B)-(i, r); (C)-(iv, p); (D)-(ii, s)

option A

Match the atomic number 19, 15, 8, 4 and 2 with each of the following :                                                                                                               

evs look, learn and experience matter: states, classification and properties study of matter general introduction: importance and scope of chemistry

  1. 19: A metal of valency one.

  2. 15: A solid non-metal of period 3

  3. 8: A rare gas

  4. 2: A gaseous element with valency 2.

  5. 4: An element of group 2.

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Correct Option: A,B,E

An atom of an element loses two electrons to form an ion. The quantum numbers of the electrons lost are $n = 4 :and :l = 0$. If another atom of the same element loses one more electron to form an ion, the quantum numbers (Principle and Azimuthal) of this electron lost are ________.

evs look, learn and experience matter: states, classification and properties study of matter general introduction: importance and scope of chemistry

  1. 1,2

  2. 3,2

  3. 3,4

  4. 4,5

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Correct Option: B
Explanation:

Quantum number $n = 4,:l = 0$ corresponds to 4s electrons. When two 4s electrons are lost, a dipositive ion is formed. The configuration of the element could be $3s^23p^64s^2 :or :3s^23p^63d^{1-10} 4s^2$. Since the atom of the same element can lose one more electron, it should be the 'd' block element. 


Iron is the element showing +2 and +3 oxidation states, the configuration could be $3s^23p^63d^64s^2$. The $3^{rd}$ electron lost has quantum numbers $n = 3$, $ l=2$.$Fe^{+3}$  is smaller than $Fe^{+2}$ ion. This is because effective nuclear force of attraction in $Fe^{+3}$  is more than that in $Fe^{+2}$.

Assuming that the number of maximum permissible shells is 5, elements would be there in the periodic table is:

evs look, learn and experience matter: states, classification and properties study of matter general introduction: importance and scope of chemistry

  1. 52

  2. 54

  3. 55

  4. 51

Show answer
Correct Option: B
Explanation:

According to Aufbau principle the order of filling of orbitals is:
$1s\ 2s\ 2p\ 3s\ 3p\ 4s\ 3d\ 4p\ 5s\ 4d\ 5p\ 6s\ 4f\ 5d\ 6p$
For maximum shell of 5, electrons will be filled upto 5p orbital as (each period)
$(1s^2)(2s^22p^6)(3s^23p^6)(4s^23d^{ 10 }4p^6)(5s^24d^{ 10 }5p^6)$
$2+8+8+18+18=54$
Therefore maximum number of atoms would be 54.
option B is correct.