A) 2H₂(g) + O₂(g) → 2H₂O(l) + 285.83 kJ
Exothermic
B) 2Mg + O₂ → 2MgO + 1200kJ
Exothermic
Answer:
option C is correct = 1.14 × 10²² molecules of CO₂
Explanation:
Given data:
Number of moles of CO₂ = 0.0189 mol
Number of molecules = ?
Solution:
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number.
For example,
18 g of water = 1 mole = 6.022 × 10²³ molecules of water
For given question:
1 mole of CO₂ = 6.022 × 10²³ molecules of CO₂
0.0189 mol of CO₂ × 6.022 × 10²³ molecules of CO₂ / 1mol
1.14 × 10²² molecules of CO₂
Thus, option C is correct.
Answer:
The water freezes and becomes solid ice
Answer:
Rotational spectroscopy, the dipole moment must change during the transition.
Rotational Raman spectroscopy, molecule must have anisotropic polarizability
Vibrational and electronic spectroscopy, molecule must have permanent dipole moment.
Explanation:
-
For the vibration rotation spectrum to be observed, it is necessary to change the dipole moment during the vibration.
- Raman scattering using an anisotropic crystal gives information about the orientation of the crystal. The polarization of Raman scattering light relative to the crystal, and the polarization of laser light, can be used to determine the orientation of the crystal, provided the crystal structure is known.
