Bonding in Ammonium and Hydroxonium Ions: Dative Covalent Bonds in Chemistry

What is a dative covalent bond?

A bond where the shared pair of electrons comes from only one of the bonding atoms.

What must one atom have to form a covalent bond?

A lone pair of electrons. (not used in bonding)

What must the other atom have to form a covalent bond?

A vacant orbital or be electron deficient.

What happens to the charge of the atom that donates electrons in a dative covalent bond?

It increases its charge by 1.

What happens to the charge of the atom that receives electrons in a dative covalent bond?

It decreases its charge by 1.

Draw and explain Bonding in the ammonium ion NH₄⁺ (use previous language to explan which one gained and lost electron)

N in ammonia uses lone pair to form dative covalent bond

N ‘loses’ electron and becomes positive

H⁺ ‘gains’ electron & becomes NEUTRAL (1 electron)

Why can ammonia form a dative covalent bond with boron trifluoride?

Ammonia donates an electron to boron trifluoride, which is electron deficient.

Draw and explain Bonding and the structure of the hydronium ion? (use prev lang)

circled H shows dative covalent bond

Why can ammonia molecules form dative covalent bond with boron trifluoride?

Draw stick diagram of this, showing dative covalent bond

H-O-N → O ARROW SHOWS DATIVE COV BOND FROM NITROGEN ATOMS

II

O