The ionization enthalpies of Li and Na are 520 kJ mol-1 and 495 kJ mol-1 respectively. The energy required to convert all the atoms present in 7 mg of Li vapours and 23 mg of sodium vapours of their respective gaseous cations respectively are

Question

The ionization enthalpies of Li and Na are 520 kJ mol-1 and 495 kJ mol-1 respectively. The energy required to convert all the atoms present in 7 mg of Li vapours and 23 mg of sodium vapours of their respective gaseous cations respectively are (A) 52 J, 49.5 J (B) 520 J, 495 J (C) 49.5 J, 52 J (D) 495 J, 520 J

Tardigrade Admin · Accepted Answer

No. of moles of Li = (7/1000 × 7) = 10-3 No. of moles of Na = (23/1000 × 23) = 10-3 ∴ The amount of energies required for 10-3 mole each of Li and Na are 520 kJ × 10-3 and 495 kJ × 10-3 or 520 J and 495 J respectively.

Q. The ionization enthalpies of $L i$ and Na are $520 k J m o l^{- 1}$ and $495 k J m o l^{- 1}$ respectively. The energy required to convert all the atoms present in $7 m g$ of $L i$ vapours and $23 m g$ of sodium vapours of their respective gaseous cations respectively are

$52 J$ , $49.5 J$

$520 J$ , $495 J$

$49.5 J$ , $52 J$

$495 J$ , $520 J$

Q. The ionization enthalpies of Li and Na are 520kJmol−1 and 495kJmol−1 respectively. The energy required to convert all the atoms present in 7mg of Li vapours and 23mg of sodium vapours of their respective gaseous cations respectively are

52J, 49.5J

520J, 495J

49.5J, 52J

495J, 520J

No. of moles of Li=1000×77​=10−3 No. of moles of Na=1000×2323​=10−3 ∴ The amount of energies required for 10−3 mole each of Li and Na are 520kJ×10−3 and 495kJ×10−3 or 520J and 495J respectively.

Q. The ionization enthalpies of $L i$ and Na are $520 k J m o l^{- 1}$ and $495 k J m o l^{- 1}$ respectively. The energy required to convert all the atoms present in $7 m g$ of $L i$ vapours and $23 m g$ of sodium vapours of their respective gaseous cations respectively are

$52 J$ , $49.5 J$

$520 J$ , $495 J$

$49.5 J$ , $52 J$

$495 J$ , $520 J$