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(a) What is meant by (i) an ionic bond, (ii) a covalent bond? (b) Describe using dot and cross diagrams the bond formation in (i) water (H₂O), (ii) sodium chloride (NaCl) - Leaving Cert Chemistry - Question 7 - 2005
Question 7
(a) What is meant by (i) an ionic bond, (ii) a covalent bond? (b) Describe using dot and cross diagrams the bond formation in (i) water (H₂O), (ii) sodium chl... show full transcript
Worked Solution & Example Answer:(a) What is meant by (i) an ionic bond, (ii) a covalent bond? (b) Describe using dot and cross diagrams the bond formation in (i) water (H₂O), (ii) sodium chloride (NaCl) - Leaving Cert Chemistry - Question 7 - 2005
Step 1
(a) What is meant by (i) an ionic bond, (ii) a covalent bond?
Answer
Ionic Bond: An ionic bond is a type of chemical bond that involves the electrostatic attraction between oppositely charged ions. This occurs when one atom donates one or more electrons to another atom, resulting in the formation of positively and negatively charged ions.
Covalent Bond: A covalent bond involves the sharing of pairs of electrons between atoms. In this type of bond, atoms share their outermost electrons to achieve a stable electronic configuration, if necessary.
Step 2
(b) Describe using dot and cross diagrams the bond formation in (i) water (H₂O), (ii) sodium chloride (NaCl).
Answer
(i) Water (H₂O):
The dot and cross diagram for water shows the oxygen atom at the center, which has six electrons in its valence shell. Each hydrogen atom has one valence electron. The oxygen atom shares its two electrons with two hydrogen atoms, resulting in two shared pairs of electrons.
H H
• •
\\ //
O
••
(ii) Sodium Chloride (NaCl):
For sodium chloride, the sodium atom (Na) has one electron in its valence shell, while chlorine (Cl) has seven. Sodium donates its one valence electron to chlorine, forming a sodium ion (Na⁺) and a chloride ion (Cl⁻).
[Na]⁺ [Cl]⁻
• •••••••
→
Step 3
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Step 5
(e) Observation: What would be observed if a charged rod was held close to the stream of water? What property of water does this experiment demonstrate?
Answer
When a charged rod is held close to the stream of water, the stream will be attracted to the rod or may bend towards it. This observation demonstrates the property of polarity in water, indicating that water is a polar molecule with positive and negative ends.