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How do you determine the melting and freezing point of naphthalene?
Hold a thermometer with its bulb in the naphthalene. Use a small flame to heat the test-tube gently and watch the thermometer reading. To find the melting range, note the temperature when the naphthalene melts. Leave to cool and note the temperature when the naphthalene solidifies.
What is the freezing point of naphthalene in benzene?
5.5 oC
1.60 g of naphthalene (C10H8) is dissolved in 20.0 g of benzene. The freezing point of pure benzene is 5.5 oC, and the freezing point of the mixture is 2.8 oC.
What is the measured freezing temperature of pure naphthalene?
Sample calculation. The freezing-point depression constant for naphthalene is 6.90 oC/m.
What happened to the naphthalene temperature during freezing?
Freezing Phase of Naphthalene But at 80o Celsius, the temperature of the naphthalene stops decreasing. The temperature remains at 80o Celsius, until freezing is complete.
What is the melting point of naphthalene in Celsius?
80 degrees C
Naphthalene is a nonpolar white solid at room temperature. It gives off a pungent odor, is highly toxic, and is considered potentially carcinogenic. Naphthalene has a melting point of 80 degrees C and a boiling point of 218 degrees C.
How do you find the freezing point?
The freezing point depression ∆T = KF·m where KF is the molal freezing point depression constant and m is the molality of the solute. Rearrangement gives: mol solute = (m) x (kg solvent) where kg of solvent is the mass of the solvent (lauric acid) in the mixture.
What is the cooling point of naphthalene?
Upon inspection of the graph and our data chart, we found the experimental freezing point of naphthalene to be around 79oC. This results in 1.4% error when compared to the actual value for the freezing point of naphthalene, 80.1oC.
Why naphthalene has a low melting point?
Explanation: Chemical formula of naphthalene is and it is a covalent compound as it contains two different non-metals. And, it is known that in covalent compounds there exist weak intermolecular forces of attraction.
How long does it take for naphthalene to freeze?
Over a time period of 12 minutes and 30 seconds, we recorded the temperature at regular 15-second intervals, and, with this data, constructed a chart showing the general curve. Upon inspection of the graph and our data chart, we found the experimental freezing point of naphthalene to be around 79oC.
What is the melting point in degrees Celsius for naphthalene?
80°C
The melting point of naphthalene is 80°C and the room temperature is 30°C. A sample of liquid naphthalene at 100°C is cooled down to the room temperature. Draw a temperature time graph to represent this cooling. In the graph, mark the region which corresponds to the freezing process.
What freezes at degrees Celsius?
Water, like all types of matter, freezes at a specific temperature. The freezing point for water is 0 degrees Celsius (32 degrees Fahrenheit).
Which will have lowest freezing point?
Hence, the depression in freezing point for cupric nitrate is maximum as it gives maximum number of particles in solution. This results in lowest freezing point.
What are the dangers of naphthalene?
f Inhaling Naphthalene can irritate the nose and throat. f High exposure to Naphthalene can cause headache, fatigue, confusion, tremor, nausea and vomiting. f Exposure to Naphthalene may cause a skin allergy. fNaphthalene may damage the liver and kidneys. fRepeated high exposure may cause anemia (low blood count). fNaphthalene is a COMBUSTIBLE SOLID. It may also be
Which liquid has the lowest freezing point?
ice is the name of the solid form of water. Many other liquid compounds can be made into solids by cooling them,but they are not called ice.
What is the melting point of napthalene?
What occur during melting of naphthalene? If heat is then added to naphthalene, it will melt until it reaches 80o C and it will stay at that temperature until melting is complete. After melting is complete, the temperature will begin to rise again until it reaches 218o C. It will stay at that point until boiling is complete.