Answer:
b. Extraction with a solution of sodium hydrogen carbonate, separating the layers, followed by drying and evaporating the organic layer.
Step-by-step explanation:
The ether solution contains your product, benzaldehyde, and some starting material, benzoic acid, the purification steps are:
- Extract with a solution of NaHCO₃. The ether layer contains benzaldehyde, and the aqueous layer contains sodium benzoate.
- Separate the layers. Keep the ether layer.
- Dry the ether solution.
- Distill the ether (boiling point 35 °C) and purify the benzaldehyde (178 °C) by steam distillation.
a. is wrong. Extraction with HCl will not remove much of the benzoic acid.
c. is wrong. If you evaporate the organic layer, you will have a mixture of benzaldehyde and benzoic acid.
d. is wrong. If you work with the aqueous layer, you will end up with benzoic acid,
Becuz the sun refelt off the earth and on to the moon.
Answer : Chemical energy to thermal energy
Explanation : When the welding torch uses the acetylene fuel for producing flame it is using the chemical acetylene to generate energy in form of light, after the flame is produced the fuel is used for melting a metal which is utilizing the thermal energy. So the ultimate final product is generated from chemical to thermal and so the energy transformation is from chemical energy to thermal energy.
The correct description for an atom of helium would be option C. An atom of helium has its valence electrons in its first energy level, it wouldn't and can't satisfy the Octet rule as it only has 2 electrons, but with 2, it has a full shell, as the first energy level can hold only 2 electrons.
