The compound X on heating gives a colourless gas. The residue is dissolved in water to obtain Y. Excess of CO2 is bubbled through aqueous solution of Y, Z is formed. Z on gentle heating gives back X. The compound X is-

(1) CaCO3                                           

(2) Na2CO3

(3) CaSO4.2H2O                                 

(4) K2CO3

Subtopic:  Compounds of Ca and Na -Preparations, Properties & Uses |
 71%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

Assertion : s-block elements do not occur free in nature

Reason :  s-block elements are highly electropositive in nature.

  1. If both the assertion and the reason are true and the reason is a correct explanation of the assertion
  2. If both the assertion and reason are true but the reason is not a correct explanation of the assertion
  3. If the assertion is true but the reason is false
  4. If both the assertion and reason are false
Subtopic:  Physical Properties |
 79%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints

The cation of alkali metals are found as M(H2O)+n in H2O, value of 'n' is maximum for

1. Na+

2. K+

3. Rb+

4. Li+

Subtopic:  Reasoning Questions |
 72%
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints

advertisementadvertisement

1 mole of substance (X) was treated with an excess of water. 2 moles of readily combustible gas were produced along with solution which when reacted with CO2 gas produced a white turbidity. The substance (X) could be

(1) Ca

(2) CaH2

(3) Ca(OH)2

(4) Ca(NO3)2

Subtopic:  Chemical Properties |
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints

A chloride dissolves appreciably in cold water. When placed on a Pt-wire in Bunsen flame, no distinctive colour is noticed. Cation present is

(1) Mg2+

(2) Ba2+

(3) Pb2+

(4) Ca2+

Subtopic:  Physical Properties |
 79%
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints

The fire extinguisher contains NaHCO3 and the compound (X). The compound (X) maybe -

1. CH3COOH

2. NaOH

3. C6H5OH

4. None of the above. 

Subtopic:  Chemical Properties |
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
Links
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

advertisementadvertisement

Alkali metals do not form nitride on reaction with N2, whereas lithium forms Li3N, because

(1) High ionisation energy of Li

(2) High lattice energy of Li3N

(3) High sublimation energy of Li

(4) High covalent nature of Li3N

Subtopic:  Physical Properties |
 55%
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints

All group-2 metals dissolve in liquid ammonia to produce a bright blue colour. The colour is due to-

1. A change in the structure of ammonia.

2. d-d transition.

3. The spectrum of the solvated electrons.

4. An electronic transition from a lower to a higher energy state.

Subtopic:  Physical Properties |
 62%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
Links
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

Hsolution is positive for

I. LiF

II. CsI

III. RbF

IV. KF

(1) I, II, III & IV

(2) II only

(3) I only

(4) I & II only

Subtopic:  Chemical Properties |
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints

advertisementadvertisement

While moving down the group (in alkaline earth metals) following property increases except

(1) Radius

(2) Solubility of hydroxides

(3) Solubility of sulphates

(4) Thermal stability of carbonates

Subtopic:  Physical Properties |
 70%
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints