Advertisements
Advertisements
Question
Define the following modes of expressing the concentration of a solution. Which of these modes are independent of temperature and why?
m (Molality)
Advertisements
Solution
The no. of moles of solute per kg of solvent
Molality (m) = `"Moles of solute"/"Mass of solvent in kg"`
Effect of temperature: Mass % ppm, mole fraction and molality do not change with temperature where as molarity, volume percentage and mass by volume percentage changes with temperature because volume of solution (liquid) varies with changes in temperature.
APPEARS IN
RELATED QUESTIONS
Define mole fraction.
A sample of drinking water was found to be severely contaminated with chloroform (CHCl3) supposed to be a carcinogen. The level of contamination was 15 ppm (by mass):
- express this in percent by mass.
- determine the molality of chloroform in the water sample.
If the density of some lake water is 1.25 g mL−1 and contains 92 g of Na+ ions per kg of water, calculate the molality of Na+ ions in the lake.
If the solubility product of CuS is 6 × 10−16, calculate the maximum molarity of CuS in aqueous solution.
Nalorphene (C19H21NO3), similar to morphine, is used to combat withdrawal symptoms in narcotic users. Dose of nalorphene generally given is 1.5 mg. Calculate the mass of 1.5 × 10−3 m aqueous solution required for the above dose.
Define Normality.
What is molal depression constant? Does it depend on nature of the solute?
Which of the following is a quantitative description of the solution?
An X molal solution of a compound in benzene has mole fraction of solute equal to 0.2. The value of X is ____________.
What is the mole fraction of solute in 1.00 m aqueous solutions?
Define the following modes of expressing the concentration of a solution. Which of these modes are independent of temperature and why?
V/V (volume percentage)
The de Broglie wavelength of a car of mass 1000 kg and velocity 36 km/hr is :
The unit of ebullioscopic constant is
A solution has been prepared by dissolving 5 g of urea in 95 g of water. What is the mass percentage of urea in the solution?
Calculated the mole fraction of benzene in a solution containing 30% by mass of its is carbon tetrachloride
138 g ethyl alcohol is mixed with 72 g of water. The ratio of mole fraction of alcohol to water is ______.
A 6.50 molal solution of KOH (aq.) has a density of 1.89 g cm−3. The molarity of the solution is ______ mol dm−3. (Round off to the Nearest Integer)
[Atomic masses: K: 39.0 u; O: 16.0 u; H: 1.0 u]
A sample of Ferrous sulphide reacts with dil. H2SO4 to from H2S which contains 9% hydrogen by volume. The percentage of fee in the sample, is ______.
The molarity of the solution prepared by dissolving 6.3 g of oxalic acid (H2C2O4 · 2 H2O) in 250 mL of water in mol L-1 is x × 10-2. The value of x is ______. (Nearest integer)
[Atomic mass: H : 1.0, C : 12.0, O : 16.0]
The mole fraction of a solute in a 100 molal aqueous solution is ______ × 10-2. (Round off to the Nearest Integer).
[Given :Atomic masses : H : 1.0 u, O : 16.0 u]
