Answer:
168°C is the melting point of your impure sample.
Explanation:
Melting point of pure camphor= T =179°C
Melting point of sample = 
= ?
Depression in freezing point = 
Depression in freezing point is also given by formula:
= The freezing point depression constant
m = molality of the sample = 0.275 mol/kg
i = van't Hoff factor
We have: = 40°C kg/mol
i = 1 ( non electrolyte)
168°C is the melting point of your impure sample.
Answer:
It shows no regular pattern
Explanation:
Physical properties of an element are those we can observe and feel with our senses. Also, the use special equipment can enhance our perception of these properties.
- The same physical property can be shared different number elements.
- On the periodic table, all the elements in group 1 and 2 are metals.
- This is not very useful for scientists whose emphasis is to distinguish one atom from the other.
- Therefore, physical properties are highly limited in the organization of the periodic table.
Answer:
Molar mass = 1.111 × 10⁻⁵ g/mol
Explanation:
Given data:
Mass of polyethylene = 1.36 g
Volume = 100 mL (0.1 L )
Pressure = 1.86 torr (1.86/760 = 0.003 atm)
Temperature = 25 °C = 25 °C + 273.15 = 298.15 K
Molar mass of polyethylene = ?
Solution :
PV =nRT
n = PV/RT
n = 0.003 atm × 0.1 L / 0.0821 atm. L . mol⁻¹ .k⁻¹ × 298.15 k
n = 0.0003 atm. L / 24.5 atm. L . mol⁻¹
n = 1.2245 × 10⁻⁵ mol
Molar mass = mass / number of moles
Molar mass = 1.36g / 1.2245 × 10⁻⁵ mol
Molar mass = 1.111 × 10⁻⁵ g/mol
