
<em>Chemists use the mole unit to represent 6.022 × 10 23 things, whether the things are atoms of elements or molecules of compounds. This number, called Avogadro's number, is important because this number of atoms or molecules has the same mass in grams as one atom or molecule has in atomic mass units. </em>
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Answer:
A) Separating funnel method
B) Simple Distillation
C) Evaporation
D) Sublimation
E) It is based on the principle of separation whereby even though two substances are dissolved in the same solvent, their respective solubilities could be different. Thus, the component that has more solubility will rise fastest and will therefore get separated from the mixture.
Explanation:
A)
B) Kerosene and petrol are both miscible liquids and the difference in their boiling point temperature is not more than 25°C. Thus, we make use of Simple distillation.
C) Can be separated by evaporation where the water is boiled and it evaporates and leaves the salt behind
D) To separate camphor from salt, we use sublimation so the camphor can change directly from solid to the gas state without passing through the liquid state.
E) Chromatography is used to separate components of a mixture.
It is based on the principle of separation whereby even though two substances are dissolved in the same solvent, their respective solubilities could be different. Thus, the component that has more solubility will rise fastest and will therefore get separated from the mixture.
It’s the 3d one
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Answer:
Hydrogen Chloride Gas is heavier than air and sinks to the ground after being released. Firefighters closer to the ground will be subjected to significantly greater concentrations of hydrogen chloride gas than the firefighters walking on top of railcars.
Explanation:
The molar mass of air is 28.97 g/mol. Air is approximately 78% N2, which has a molar mass of 28.014 g/mol and 21% oxygen, which has a molar mass of 32 g/mol; the remaining constituents of air include CO2 and other trace amounts of gases.
The molar mass of HCl is 36.458 g/mol.
Because HCl is heavier than air, it sinks toward the ground, displacing the lighter air.
The height of railway cars is reported to vary between 13.5 ft to 15.5 ft. So firefighters on tank cars are generally above the HCl gas (although localized atmospheric conditions could cause the HCl to move higher up in the air column).