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CHXI11:THE P-BLOCK ELEMENTS

316532 Consider these two sets of bond enthalpies (in $kJ / mol$ ):
$X = [\begin{array}{cccc} C - C & Si - Si & Ge - Ge & Sn - Sn \\ 240 & 260 & 297 & 348 \end{array}]$
(corresponding values are not in the same order)
$Y = [\begin{array}{cccc} C - F & C - Cl & Si - F & Si - Cl \\ 326 & 360 & 439 & 536 \end{array}]$
Sum of bond enthalpies for $C - C$ and $Si - F$ bond is ____.

1 348

2 536

3 884

4 1080

Explanation:

$(X)$ The reason of high catenation tendency of carbon is its high bond energy.
Bond energy for $C - C = 348 kJ / mol$
(Y) The difference in electronegativity is highest for $Si - F$ bond.
Hence, bond energy for $Si - F = 536 kJ / mol$
Sum of bond enthalpies $= 348 + 536$
$= 884 kJ / mol$

CHXI11:THE P-BLOCK ELEMENTS

316533 In the carbon family the melting points of the elements decrease on descending the group because the interatomic bonds become:

1 Stronger as the size of the atom increases

2 Weaker as the size of the atom decreases

3 Stronger as the size of the atom decreases

4 Weaker as the size of the atom increases

CHXI11:THE P-BLOCK ELEMENTS

316534 Which has highest melting point?

1 Silicon

2 Lead

3 Tin

4 Diamond

Explanation:

$Element M .P (^{\circ} C)$
$Si 1414$
$Pb 327$
$Sn 231$
$Diamond 3927(4200K)$

CHXI11:THE P-BLOCK ELEMENTS

316535 The correct order of bond enthalpy $({kJmol}^{- 1})$ is:

1

C - C > Si - Si > Ge - Ge > Sn - Sn

2

Si - Si > C - C > Ge - Ge > Sn - Sn

3

C - C > Si - Si > Sn - Sn > Ge - Ge

4

Si - Si > C - C > Sn - Sn > Ge - Ge

Explanation:

supporting img

So, the correct order is $C - C > Si - Si > Ge -$ $Ge > Sn - Sn$

JEE - 2023

CHXI11:THE P-BLOCK ELEMENTS

316532 Consider these two sets of bond enthalpies (in $kJ / mol$ ):
$X = [\begin{array}{cccc} C - C & Si - Si & Ge - Ge & Sn - Sn \\ 240 & 260 & 297 & 348 \end{array}]$
(corresponding values are not in the same order)
$Y = [\begin{array}{cccc} C - F & C - Cl & Si - F & Si - Cl \\ 326 & 360 & 439 & 536 \end{array}]$
Sum of bond enthalpies for $C - C$ and $Si - F$ bond is ____.

1 348

2 536

3 884

4 1080

Explanation:

$(X)$ The reason of high catenation tendency of carbon is its high bond energy.
Bond energy for $C - C = 348 kJ / mol$
(Y) The difference in electronegativity is highest for $Si - F$ bond.
Hence, bond energy for $Si - F = 536 kJ / mol$
Sum of bond enthalpies $= 348 + 536$
$= 884 kJ / mol$

CHXI11:THE P-BLOCK ELEMENTS

316533 In the carbon family the melting points of the elements decrease on descending the group because the interatomic bonds become:

1 Stronger as the size of the atom increases

2 Weaker as the size of the atom decreases

3 Stronger as the size of the atom decreases

4 Weaker as the size of the atom increases

CHXI11:THE P-BLOCK ELEMENTS

316534 Which has highest melting point?

1 Silicon

2 Lead

3 Tin

4 Diamond

Explanation:

$Element M .P (^{\circ} C)$
$Si 1414$
$Pb 327$
$Sn 231$
$Diamond 3927(4200K)$

CHXI11:THE P-BLOCK ELEMENTS

316535 The correct order of bond enthalpy $({kJmol}^{- 1})$ is:

1

C - C > Si - Si > Ge - Ge > Sn - Sn

2

Si - Si > C - C > Ge - Ge > Sn - Sn

3

C - C > Si - Si > Sn - Sn > Ge - Ge

4

Si - Si > C - C > Sn - Sn > Ge - Ge

Explanation:

supporting img

So, the correct order is $C - C > Si - Si > Ge -$ $Ge > Sn - Sn$

JEE - 2023

CHXI11:THE P-BLOCK ELEMENTS

316532 Consider these two sets of bond enthalpies (in $kJ / mol$ ):
$X = [\begin{array}{cccc} C - C & Si - Si & Ge - Ge & Sn - Sn \\ 240 & 260 & 297 & 348 \end{array}]$
(corresponding values are not in the same order)
$Y = [\begin{array}{cccc} C - F & C - Cl & Si - F & Si - Cl \\ 326 & 360 & 439 & 536 \end{array}]$
Sum of bond enthalpies for $C - C$ and $Si - F$ bond is ____.

1 348

2 536

3 884

4 1080

Explanation:

$(X)$ The reason of high catenation tendency of carbon is its high bond energy.
Bond energy for $C - C = 348 kJ / mol$
(Y) The difference in electronegativity is highest for $Si - F$ bond.
Hence, bond energy for $Si - F = 536 kJ / mol$
Sum of bond enthalpies $= 348 + 536$
$= 884 kJ / mol$

CHXI11:THE P-BLOCK ELEMENTS

316533 In the carbon family the melting points of the elements decrease on descending the group because the interatomic bonds become:

1 Stronger as the size of the atom increases

2 Weaker as the size of the atom decreases

3 Stronger as the size of the atom decreases

4 Weaker as the size of the atom increases

CHXI11:THE P-BLOCK ELEMENTS

316534 Which has highest melting point?

1 Silicon

2 Lead

3 Tin

4 Diamond

Explanation:

$Element M .P (^{\circ} C)$
$Si 1414$
$Pb 327$
$Sn 231$
$Diamond 3927(4200K)$

CHXI11:THE P-BLOCK ELEMENTS

316535 The correct order of bond enthalpy $({kJmol}^{- 1})$ is:

1

C - C > Si - Si > Ge - Ge > Sn - Sn

2

Si - Si > C - C > Ge - Ge > Sn - Sn

3

C - C > Si - Si > Sn - Sn > Ge - Ge

4

Si - Si > C - C > Sn - Sn > Ge - Ge

Explanation:

supporting img

So, the correct order is $C - C > Si - Si > Ge -$ $Ge > Sn - Sn$

JEE - 2023

CHXI11:THE P-BLOCK ELEMENTS

316532 Consider these two sets of bond enthalpies (in $kJ / mol$ ):
$X = [\begin{array}{cccc} C - C & Si - Si & Ge - Ge & Sn - Sn \\ 240 & 260 & 297 & 348 \end{array}]$
(corresponding values are not in the same order)
$Y = [\begin{array}{cccc} C - F & C - Cl & Si - F & Si - Cl \\ 326 & 360 & 439 & 536 \end{array}]$
Sum of bond enthalpies for $C - C$ and $Si - F$ bond is ____.

1 348

2 536

3 884

4 1080

Explanation:

$(X)$ The reason of high catenation tendency of carbon is its high bond energy.
Bond energy for $C - C = 348 kJ / mol$
(Y) The difference in electronegativity is highest for $Si - F$ bond.
Hence, bond energy for $Si - F = 536 kJ / mol$
Sum of bond enthalpies $= 348 + 536$
$= 884 kJ / mol$

CHXI11:THE P-BLOCK ELEMENTS

316533 In the carbon family the melting points of the elements decrease on descending the group because the interatomic bonds become:

1 Stronger as the size of the atom increases

2 Weaker as the size of the atom decreases

3 Stronger as the size of the atom decreases

4 Weaker as the size of the atom increases

CHXI11:THE P-BLOCK ELEMENTS

316534 Which has highest melting point?

1 Silicon

2 Lead

3 Tin

4 Diamond

Explanation:

$Element M .P (^{\circ} C)$
$Si 1414$
$Pb 327$
$Sn 231$
$Diamond 3927(4200K)$

CHXI11:THE P-BLOCK ELEMENTS

316535 The correct order of bond enthalpy $({kJmol}^{- 1})$ is:

1

C - C > Si - Si > Ge - Ge > Sn - Sn

2

Si - Si > C - C > Ge - Ge > Sn - Sn

3

C - C > Si - Si > Sn - Sn > Ge - Ge

4

Si - Si > C - C > Sn - Sn > Ge - Ge

Explanation:

supporting img

So, the correct order is $C - C > Si - Si > Ge -$ $Ge > Sn - Sn$

JEE - 2023