Answer:
81.0°C
Explanation:
<em>Kb benzene = 2.5°C/m</em>
<em />
The addition of a solute to a pure solvent produce an elevation in boiling point regarding to boiling point of pure solvent. This phenomenon follows the equation:
ΔT = Kb×m×i
<em>where ΔT represents the increasing in boiling point, Kb is the elevation boiling point constant of the solvent (2.5°C/m for benzene), m is molality of solution (Moles solute / kg solvent) and i is Van't Hoff factor (1 for a non-electrolyte solute as naphthalene).</em>
<em />
Moles of 11.5g of naphthalene (Molar mass: 128.17g/mol) are:
11.5g × (1mol / 128.17g) =<em> 0.0897 moles of naphthalene in 250.0g = 0.250kg of benzene.</em>
Molality is:
0.0897 moles of naphthalene / 0.250kg of benzene = 0.359m
Replacing in the equation:
ΔT = Kb×m×i
ΔT = 2.5°C/m×0.359m×1
ΔT = 0.90°C
That means the solution prepared has an elevation in boiling point of 0.90°C. As boiling point of pure benzene is 80.10°C, boiling point of the solution is:
80.10°C + 0.90°C =
<h3>81.0°C</h3>
They have 2 oxygen atoms in 02
Answer:
- <em>If a piece of iron were placed close to this device, the iron nail would move toward the piece of iron.</em>
Explanation:
The description of the built device corresponds to a temporal electromagnet: as long as the battery is connected and supplying the potential difference (voltage) the iron nail will have magnet properties.
Since magnets attract and are attracted to iron, the iron nail and the piece of iron would feel attracted to each other.
The question is confusing because it asks what would happen to a piece of iron if it were placed close to this device, but it should be what happens to the iron nail if a piece of iron were placed close to this device.
Then, assuming the iron nail is free to move it would move toward the piece of iron due to the electromagnetic force.
The answer is B. physical deposition because freezing and thawing are physical factors that affect weathering.
<h3> Answer:</h3><h3>•A catalyst is substance i.e a element or a compound that increases the rate of chemical reaction. </h3><h3>Examples: </h3><h3>1) Nickel, Ni is used in hydrogenation of palm oil into margarine.</h3><h3>2) Iron, Fe is used in Haber process. (Manufacturing of ammonia)</h3><h3>3) Nickel, platinum, or palladium.</h3><h3>4) Copper(II) oxide, vanadium(V) oxide, platinum, palladium.</h3><h3>5) Aluminum chloride, hydrogen chloride.</h3><h3>Explanation:</h3>
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