Answer : The correct answer for change in freezing point = 1.69 ° C
Freezing point depression :
It is defined as depression in freezing point of solvent when volatile or non volatile solute is added .
SO when any solute is added freezing point of solution is less than freezing point of pure solvent . This depression in freezing point is directly proportional to molal concentration of solute .
It can be expressed as :
ΔTf = Freezing point of pure solvent - freezing point of solution = i* kf * m
Where : ΔTf = change in freezing point (°C)
i = Von't Hoff factor
kf =molal freezing point depression constant of solvent.
m = molality of solute (m or 
)
Given : kf = 1.86 
m = 0.907 )
Von't Hoff factor for non volatile solute is always = 1 .Since the sugar is non volatile solute , so i = 1
Plugging value in expression :
ΔTf = 1* 1.86 * 0.907 )
ΔTf = 1.69 ° C
Hence change in freezing point = 1.69 °C
Answer:
No, in science their meanings are not the same as their everyday meanings.
Explanation:
In Science, Precision and Accuracy are defined as,
Accuracy:
Accuracy is the value which is closest to the known or standard value.
Precision:
While, Precision is the value of closeness of two measured values to each other.
Example:
Let suppose in Chemistry Lab you weight an object as 50 g. While the actual weight of that object is 30 g. It means your reading is not accurate.
On second measurement you find that the object weight is 31 g. This time your reading is not precise.
Answer: The correct answer is option B)
in the synthesis of cryolite for aluminum production.
Explanation:
Hydrogen fluoride (HF) is used in synthesis of cryolite for aluminum production.
HF is a gas that dissolves in water to form hydrofluoric acid. However, HF also react with halogenated alkanes like trichloromethane CHCl3 to form organofluorine compounds that serves as precursors in the synthesis of cryolite, an Ore from which aluminum is produced
The particles of the gases are apart from each other and they are movingoing freely, However, in the solid the particles are very close to each other and there is no spaces between them,
Answer:
Explanation:
The density of a gas can be obtained using the gas ideal equation and the molar mass of the gas.
This is the decution of the final formula:
Now, you just need to substitute values:
- R = 0.08206 atm-liter / k-mol
- d = 32.0 g/mol × 0.9869 atm / [0.08206 atm-liter/k-mol × 273.15K]
- d = 1.4 g/liter (using two significant figures)
As you see, I have not used the 4.8 grams datum. That is because the density of the gases may be calculated from the temperature, pressure and molar mass of the gas, using the ideal gas equation.
Since, you have the mass of gas, you might use this other procedure:
- Volume of 1 mol of gas at STP: about 22.4 liter/mol
- Mass of 1 mol of oxygen gas: 32.0 g/mol (the molar mass)
- number of moles in 4.8 g of oxygen = 4.8 g / 32.0 g/mol = 0.15 mol
- Volume of 0.15 mol of oxygen: 0.15 mol × 22.4 liter/mol = 3.36 liter
- Density = mass / volume = 4.8 g / 3.36 liter = 1.4 g/liter (same result)
