Boron trifluoride (BF₃) forms a compound with ammonia (NH₃). Describe the type of bond formed

• Shared pair of bonding electrons is provided by B atom

• Shared pair of bonding electrons is provided by N atom

• Dative bond between B and F

• Dative bond between B and N

The resonance structures of nitric acid molecule are..

• 
• 
• 
• 

The three resonance structures for thiocyanate ion, SCN– are given above:

Give the most stable Lewis structure

• I

• II

• III

• All answers above

The best reason for the most plausible Lewis structure [SCN]^-

• The formal charge is -2 for Nitrogen & +1 for Sulphur.

• The negative formal charge is on more electronegative atom, Nitrogen.

• The negative formal charge is on more electronegative atom, Carbon.

• The structure having the smallest formal charge

Give the formula for the compound formed when element T combine with U and state the type of bond formed.

• TU₂ : IONIC BOND

• UT₂ : IONIC BOND

• UT : COVALENT BOND

• UT : IONIC BOND

Antimony (Sb) is found in the fifth period and Group 15 of the periodic table. How many number of electron in the valence shell electronic configuration of antimony.

• 3

• 5

• 11

• 15

Based on its valence shell electronic configuration of Sb,(5s² 5p³), predict the possible formulae of fluorides of antimony.

• SbF₂

• SbF₃

• SbF₅

• Sb₂F₃

State the hybridisation of the central atom in molecule SbF₃

• sp²

• sp³

• sp³d

• sp³d²

State the hybridisation of the central atom in molecule SbF₅

• sp²

• sp³

• sp³d

• sp³d²

Predict the shapes and polarity of the SbF₃ molecule

• Tetrahedral & polar

• Trigonal planar & non-polar

• Trigonal pyramidal & polar

• Trigonal pyramidal & non-polar