The heat of atomization of methane and ethane are 360 kJ/mol and 620 kJ/mol, respectively. The longest wavelength of light capable of breaking the C - C bond is (Avogadro number = 6.02 × 1023, h = 6.62 × 10-34 J s) :

Question

The heat of atomization of methane and ethane are 360 kJ/mol and 620 kJ/mol, respectively. The longest wavelength of light capable of breaking the C - C bond is (Avogadro number = 6.02 × 1023, h = 6.62 × 10-34 J s) : (A) 1.49 × 103 nm (B) 2.48 × 103 nm (C) 2.48 × 104 nm (D) 1.49 × 104 nm

Tardigrade Admin · Accepted Answer

CH 4 arrow C +4 H Δ H=360 4( C - H )=360 B . E . of C - H =90 kJ C 2 H 6 arrow 2 C +6 H Δ H=620 1( C - C )+6( C - H )=620 ⇒ 1( C - C )+6 × 90=620 B. E of C - C =80 kJ E =(h C/λ) ⇒ 80 × 103=(6.62 × 10-34 × 3 × 108/λ)

Q. The heat of atomization of methane and ethane are $360 k J / m o l$ and $620 k J / m o l,$ respectively. The longest wavelength of light capable of breaking the C - C bond is (Avogadro number $= 6.02 \times 1 0^{23}, h = 6.62 \times 1 0^{- 34} J s$ ) :

$1.49 \times 1 0^{3} nm$

$2.48 \times 1 0^{3} nm$

$2.48 \times 1 0^{4} nm$

$1.49 \times 1 0^{4} nm$

Q. The heat of atomization of methane and ethane are 360kJ/mol and 620kJ/mol, respectively. The longest wavelength of light capable of breaking the C - C bond is (Avogadro number =6.02×1023,h=6.62×10−34Js) :

1.49×103nm

2.48×103nm

2.48×104nm

1.49×104nm

CH4​→C+4HΔH=360 4(C−H)=360 B.E. of C−H=90kJ C2​H6​→2C+6HΔH=620 1(C−C)+6(C−H)=620⇒1(C−C)+6×90=620 B.E of C−C=80kJ E=λhC​ ⇒80×103=λ6.62×10−34×3×108​

Q. The heat of atomization of methane and ethane are $360 k J / m o l$ and $620 k J / m o l,$ respectively. The longest wavelength of light capable of breaking the C - C bond is (Avogadro number $= 6.02 \times 1 0^{23}, h = 6.62 \times 1 0^{- 34} J s$ ) :

$1.49 \times 1 0^{3} nm$

$2.48 \times 1 0^{3} nm$

$2.48 \times 1 0^{4} nm$

$1.49 \times 1 0^{4} nm$