Chemistry questions and answers

Chemistry Questions and Answers

Learn more about the properties, composition, and structure of substances (elements and compounds) with these Chemistry questions and answers. This Test can be used by students preparing for Chemistry in JAMB, WAEC, NECO or Post UTME.

461.

Hydrogen bond is a sort of

A.

van der waals force

B.

dative bond

C.

ionic bond

D.

a covalent bond

Correct answer is D

Hydrogen bond is a covalent intermolecular bond that exists between hydrogen and highly electronegative elements like nitrogen, oxygen and fluorine.

462.

The oxidation state(s) of nitrogen in ammonium nitrite is/are

A.

-3, +3

B.

+5

C.

-3, +5

D.

-3

Correct answer is A

Ammonium nitrite = NH\(_4\)NO\(_2\)

NH\(_4 ^+\): Let the oxidation number of Nitrogen = x

x + 4 = 1 \(\implies\) x = 1 - 4

x = -3

NO\(_2 ^-\): x - 4 = -1

x = -1 + 4 \(\implies\) x = +3.

The oxidation numbers for Nitrogen in Ammonium Nitrite = -3, +3.

463.

Which quantum divides shells into orbitals?

A.

Spin

B.

Principal

C.

Azimuthal

D.

Magnetic

Correct answer is C

The azimuthal quantum number determines an atom's orbital angular momentum and the shape of the orbital. The principal quantum number determines its number of shells. Magnetic quantum number determines how many orbitals there are as well as their orientation within a subshell.

464.

The shapes of water, ammonia, carbon (iv) oxide and methane are respectively

A.

linear, tetrahedral, angular and pyramidal

B.

angular, pyramidal, linear and tetrahedral

C.

pyramidal, linear, tetrahedral and angular

D.

tetrahedral, angular, pyramidal and linear

Correct answer is B

Ammonia \((NH_3\)) has a trigonal pyramidal structure with a bond angle of approximately 107 degrees. Methane (\(CH_4\)) has a tetrahedral structure with a bond angle of 109.5 degrees. Carbon dioxide is a linear molecule, with a 180-degree bond angle. Water \((H_2O\)) has a bent or V-shaped structure with a bond angle of approximately 104.5 degrees.

465.

A cell shorthand notation can be written as A / A\(^+\) // B\(^{2+}\) /B. The double slash in the notation represents the 

A.

electrolyte

B.

electrodes

C.

salt bridge

D.

solid - liquid interface

Correct answer is C

No explanation has been provided for this answer.