Page 49 - Chemistry ICSE Class X

Chemical Bonding 37
Ans. From the charges on the ions, the ratio of the numbers of positive and negative ions in the compound can be
HQWPF QWV 6JKU IKXGU VJG GORKTKECN HQTOWNC 6JG GNGEVTQP FQV UVTWEVWTG KU VJGP GCUKN[ YTKVVGP CU HQNNQYU
Ion
Cation Anion Formula Electron dot structure
K + O 2– K O K O (K )
+
1+
2–
2 2
o
o
2+
Ca 2+ Cl – Ca o o Cl CaCl 2 (Ca )
–
2+
Na + S 2– Na o o S Na S (Na )
+
2–
+
2
2
Al 3+ F – Al o o F AlF 3 (Al )
3+
–
3+
+
Na + P 3– Na o o P Na P (Na )
3–
+
3
3
ASSIGNMENT 3
Electrovalent (or Ionic) bond, Structures of some electrovalent compounds, Electrovalent compounds
ϭ͘ ,Žǁ ŝƐ ĂŶ ĞůĞĐƚƌŽǀĂůĞŶƚ ďŽŶĚ ĨŽƌŵĞĚ͍
Ϯ͘ tŚŝĐŚ ŽĨ ƚŚĞ ĨŽůůŽǁŝŶŐ ĐŽŵƉŽƵŶĚƐ ŚĂǀĞ ĞůĞĐƚƌŽǀĂůĞŶƚ ďŽŶĚƐ ŝŶ ƚŚĞŵ͍
E Ă ů ͕ , ^͕ EĂ,͕ , ͕ ĂK͕ , O
Ϯ ϰ Ϯ
ϯ͘ tŚŝĐŚ ĞůĞŵĞŶƚƐ ĨŽƌŵ ĞůĞĐƚƌŽǀĂůĞŶƚ ĐŽŵƉŽƵŶĚƐ ĞĂƐŝůLJ͍
ϰ͘ ĞƐĐƌŝďĞ ƚŚĞ ĨŽƌŵĂƟŽŶ ŽĨ ƉŽƚĂƐƐŝƵŵ ĐŚůŽƌŝĚĞ ;< ůͿ ďLJ ŵĞĂŶƐ ŽĨ ĞůĞĐƚƌŽŶ ĚŽƚ ĚŝĂŐƌĂŵ͘
ϱ͘ :ƵƐƟĨLJ ƚŚĂƚ ŵĂŐŶĞƐŝƵŵ ŽdžŝĚĞ ĐĂŶ ďĞ ĚĞƐĐƌŝďĞĚ ďLJ ƚŚĞ ĨŽƌŵƵůĂ ;DŐKͿ ďLJ ŵĞĂŶƐ ŽĨ ĞůĞĐƚƌŽŶ ĚŽƚ ĚŝĂŐƌĂŵ͘
ϲ͘ ƌĂǁ ƚŚĞ ĞůĞĐƚƌŽŶ ĚŽƚ ĚŝĂŐƌĂŵ ĨŽƌ ƚŚĞ ĨŽƌŵĂƟŽŶ ŽĨ ƐŽĚŝƵŵ ƐƵůƉŚŝĚĞ ;EĂ ^Ϳ͘
Ϯ
ϳ͘ Ŷ ĂƚŽŵ ŚĂƐ ŽŶĞ ĞůĞĐƚƌŽŶ ŵŽƌĞ ƚŚĂŶ ƚŚĞ ŶŽďůĞ ŐĂƐ ĐŽŶĮŐƵƌĂƟŽŶ͘ tŚĂƚ ƚLJƉĞ ŽĨ ŝŽŶ ǁŽƵůĚ ŝƚ ƚĞŶĚ ƚŽ ĨŽƌŵ͍ [Ans. ĂƟŽŶ΁
ϴ͘ tƌŝƚĞ ŐĞŶĞƌĂů ŶĂŵĞ ĨŽƌ ƚŚĞ ĐŽŵƉŽƵŶĚƐ ŵĂĚĞ ƵƉ ŽĨ ŝŽŶƐ͘
ϵ͘ LJ ǁŚŝĐŚ ŵĞĐŚĂŶŝƐŵ Žƌ ŵĞĐŚĂŶŝƐŵƐ͕ ƚŚĞ ĂƚŽŵƐ ŽĨ ǀĂƌŝŽƵƐ ĞůĞŵĞŶƚƐ ĂƩĂŝŶ ŶŽďůĞ ŐĂƐ ĐŽŶĮŐƵƌĂƟŽŶƐ͍
ϭϬ͘ ĐŽŵƉŽƵŶĚ ŚĂƐ ŚŝŐŚ ŵĞůƟŶŐ ĂŶĚ ďŽŝůŝŶŐ ƉŽŝŶƚƐ͘ tŚĞŶ ŝŶ ƚŚĞ ƐŽůŝĚ ƐƚĂƚĞ͕ ŝƚ ĚŽĞƐ ŶŽƚ ĐŽŶĚƵĐƚ ĞůĞĐƚƌŝĐŝƚLJ͘ tŚĞŶ ŝƚ ŝƐ
ŵĞůƚĞĚ͕ ƚŚĞ ŵŽůƚĞŶ ĐŽŵƉŽƵŶĚ ĐŽŶĚƵĐƚƐ ĞůĞĐƚƌŝĐŝƚLJ͘ tŚĂƚ ƚLJƉĞ ŽĨ ĐŽŵƉŽƵŶĚ ŝƐ ŝƚ͍ tŚĂƚ ĂƌĞ ƚŚĞ ĐŽŶƐƟƚƵĞŶƚ ƵŶŝƚƐ ŽĨ ƚŚŝƐ
ĐŽŵƉŽƵŶĚ͍
ϭϭ͘ ŵĞƚĂůůŝĐ ĞůĞŵĞŶƚ D ĨŽƌŵƐ ĂŶ ŝŽŶŝĐ ŽdžŝĚĞ D K͘ ,Žǁ ŵĂŶLJ ĞůĞĐƚƌŽŶƐ ĂŶ ĂƚŽŵ ŽĨ D ŚĂƐ ŝŶ ŝƚƐ ǀĂůĞŶĐĞ ƐŚĞůů͍ [Ans. KŶĞ΁
Ϯ
ϭϮ͘ /Ŷ ƚŚĞ ĨŽƌŵĂƟŽŶ ŽĨ ĐŽŵƉŽƵŶĚ yz ͕ ĂƚŽŵ y ŐŝǀĞƐ ŽŶĞ ĞůĞĐƚƌŽŶ ƚŽ ĞĂĐŚ z ĂƚŽŵ͘
Ϯ
tŚĂƚ ŝƐ ƚŚĞ ŶĂƚƵƌĞ ŽĨ ďŽŶĚƐ ŝŶ yz ͍ 'ŝǀĞ ƚǁŽ ƉƌŽƉĞƌƟĞƐ ŽĨ yz ͘ [Ans. ŝŽŶŝĐ ďŽŶĚ΁
Ϯ Ϯ
ϭϯ͘ ůĞĐƚƌŽŶŝĐ ĐŽŶĮŐƵƌĂƟŽŶ ŽĨ ĂŶ ĂƚŽŵ y ŝƐ ;Ϯ͕ϴ͕ϳͿ͘ /ƚ ĐŽŵďŝŶĞƐ ǁŝƚŚ ĂŶŽƚŚĞƌ ĂƚŽŵ z ŚĂǀŝŶŐ ĞůĞĐƚƌŽŶŝĐ ĐŽŶĮŐƵƌĂƟŽŶ ;ϭͿ͘
;ĂͿ tŚĂƚ ƚLJƉĞ ŽĨ ďŽŶĚ ǁŝůů ďĞ ĨŽƌŵĞĚ ďĞƚǁĞĞŶ y ĂŶĚ z͍
;ďͿ tƌŝƚĞ ƚŚĞ ĨŽƌŵƵůĂ ŽĨ ƚŚĞ ĐŽŵƉŽƵŶĚ ĨŽƌŵĞĚ͘
;ĐͿ /Ɛ ŝƚ ƐŽůƵďůĞ ŝŶ ǁĂƚĞƌ͍
ϭϰ͘ dŚĞ ǀĂůĞŶĐŝĞƐ ;Žƌ ĐŚĂƌŐĞƐͿ ŽŶ ƐŽŵĞ ŝŽŶƐ ĂƌĞ ŐŝǀĞŶ ďĞůŽǁ͗
ŝŶĐ ŝŽŶ Ϯн EŝƚƌŽŐĞŶ ŝŽŶ ϯʹ KdžŝĚĞ ŝŽŶ Ϯʹ WŚŽƐƉŚĂƚĞ ŝŽŶ ϯʹ
^ŽĚŝƵŵ ŝŽŶ ϭн ƌŽŵŝĚĞ ŝŽŶ ϭʹ >ĞĂĚ ŝŽŶ Ϯн
hƐŝŶŐ ƚŚĞ ĂďŽǀĞ ŝŶĨŽƌŵĂƟŽŶ͕ ǁƌŝƚĞ ĚŽǁŶ ƚŚĞ ĐŚĞŵŝĐĂů ĨŽƌŵƵůĂĞ ŽĨ ƚŚĞ ĨŽůůŽǁŝŶŐ͗
;ĂͿ ŝŶĐ ƉŚŽƐƉŚĂƚĞ ;ďͿ EŝƚƌŽŐĞŶ ŽdžŝĚĞ ;ĐͿ ^ŽĚŝƵŵ ƉŚŽƐƉŚĂƚĞ ;ĚͿ >ĞĂĚ ďƌŽŵŝĚĞ
Covalent Bond
Atoms can also combine with other atoms by mutual sharing of electrons. Mutual sharing of electrons means
that each of the combining atoms contribute equal number of electrons. These pooled electrons are counted
VQYCTFU VJG GNGEVTQPKE EQPſIWTCVKQP QH DQVJ VJG CVQOU. For example, when two hydrogen atoms combine,
they contribute one electron each, and the ‘pooled pair’ of electrons is shared by both the hydrogen atoms
equally, as shown on the next page.
The pooled pair of electrons is called the shared pair of electrons.