The heat required to vaporize 43.9 g of acetone at its boiling point is calculated as below
the heat of vaporization of acetone at its boiling point is 29.1 kj/mole
find the moles of acetone = mass/molar mass
= 43.9g /58 g/mol =0.757 moles
heat (Q) = moles x heat of vaporization
= 29.1 kj/mole x 0.757 moles = 22.03 kj
Answer:
B- gravity
Explanation:
Gravity is a force in which everything in the universe is trying to pull everyother thing towards themsef. Here, the sun's gravity keeps the planet in orbit.
I hope im right! !!
2NaCN(s) + H₂SO₄(aq) --> Na₂SO₄(aq) + 2HCN(g)
The molar ratio between NaCN : HCN is 2:2 or 1:1
Mass of HCN = 16.7 g
Molar mass of HCN = 1 + 12 + 14 = 27 g/mol
Molar mass of NaCN = 49 g/mol
Therefore, the mass of NaCN is
16.7 g of HCN x 49 g/mol of NaCN / 27 g/mol of HCN = 30.3 grams of NaCN
Therefore, 30.3 grams of NaCN gives the lethal dose in the room.
Answer:
E) Intramolecular bond angles change
Explanation:
Infrared Radiation:
IR is electromagnetic radiations. The wavelength i.e. 700nm to 1000 mm of infrared is longer than invisible light and Its frequency is lower than light, that's why it is invisible to light.
- When IR radiation strike the molecule it absorbed by this molecule.
- This radiation used to identify and study chemicals.
- Infrared radiation interact with intra-bonds of the molecule.
- Bonds in the molecules have vibrational translational and rotational movements
- Due to these vibration, rotation and translation movement it absorb a radiation of specific frequency and wavelength
- These movements of bond are very small and absorbs radiations of very low frequency
- So when Infrared light or radiation absorbed the intra-bonds of the molecule get affected and angles of these bonds changes.
- As the frequency of the absorbed radiation matches the frequency of the bond that vibrates.
So
The correct option is option E
E) Intramolecular bond angles change
* Note:
it couldn't be option A as the frequency of IR is not enough to rotate a whole molecule
It Couldn't be option B as IR rations are electromagnetic radiation of longer wave length so it one can not see it with light so how it will glow a molecule
It also not could be the option C as for the excitation of electrons require much higher energy.
It also not the option D as nuclear magnetic spin is associated with nuclear magnetic radiation that are much different from IR.
