Advertisements
Advertisements
प्रश्न
Define molality.
Define the following term:
Molality
Advertisements
उत्तर
Molality (m) is defined as the number of moles of the solute dissolved in one kilogram (kg) of the solvent. The units of molality are moles per kilogram, i.e., mole kg−1. The molality is preferred over molarity if the volume of the solution is either expanding or contracting with temperature.
Molality (m) = `"Number of mole of solute"/"Mass of solvent (in kg)"`
APPEARS IN
संबंधित प्रश्न
Calculate the mass percentage of benzene (C6H6) and carbon tetrachloride (CCl4) if 22 g of benzene is dissolved in 122 g of carbon tetrachloride.
Calculate the mole fraction of benzene in solution containing 30% by mass in carbon tetrachloride.
Calculate the molarity of the following solution:
30 g of Co(NO3)2 . 6H2O in 4.3 L of solution.
Calculate the mass of urea (NH2CONH2) required in making 2.5 kg of 0.25 molal aqueous solution.
Define molarity (M).
Define mass percentage.
Concentrated nitric acid used in laboratory work is 68% nitric acid by mass in aqueous solution. What should be the molarity of such a sample of the acid if the density of the solution is 1.504 g mL−1?
A solution of glucose in water is labelled as 10% w/w, what would be the molality and mole fraction of each component in the solution? If the density of solution is 1.2 g mL−1, then what shall be the molarity of the solution?
A solution is obtained by mixing 300 g of 25% solution and 400 g of 40% solution by mass. Calculate the mass percentage of the resulting solution.
An antifreeze solution is prepared from 222.6 g of ethylene glycol (C2H6O2) and 200 g of water. Calculate the molality of the solution. If the density of the solution is 1.072 g mL−1, then what shall be the molarity of the solution?
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.
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.
A sample of 12 M Concentrated hydrochloric acid has a density 1.2 M gL-1 calculate the molality.
Molality of a solution relates the ____________.
1 M, 2.5 litre NaOH solution is mixed with another 0.5 M, 3 litre NaOH solution. Then find out the molarity of the resultant solution:
An aqueous solution of glucose is 10% in strength. The volume in which 1 g mole of it is dissolved, will be:
On adding a solute to a solvent having vapour pressure 0.80 atm, vapour pressure reduces to 0.60 atm. Mole fraction of solute is:
The mole fraction of the solute in one molal aqueous solution is ____________.
5 ml of N HCl, 20 ml of N/2 H2SO4 and 30 ml of N/3 HNO3 are mixed together and volume made to one litre. The normality of the resulting solution is:
25 ml of a solution of barium hydroxide on titration with a 0.1 molar solution of hydrochloric acid gave a titre value of 35 ml. The molarity of barium hydroxide solution was ______.
Mole fraction of the solute in a 1.00 molal aqueous solution is ____________.
What is the normality of a 1 M solution of H3PO4?
200 ml of water is added to 500 ml of 0.2 M solution. What is the molarity of this diluted solution?
Which of the following concentration terms is/are independent of temperature?
A solution is prepared by dissolving 10 g NaOH in 1250 mL of a solvent of density 0.8 mL/g. The molality of the solution in mol kg–1 is:
Which of the following units is useful in relating concentration of solution with its vapour pressure?
Out of molality (m), molarity (M), formality (F) and mole fraction (x), those which are independent of temperature are:
4 L of 0.02 M aqueous solution of NaCl was diluted by adding one litre of water. The molality of the resultant solution is ______.
Which of the following is a correct statement for C2H5Br?
Match the terms given in Column I with expressions given in Column II.
| Column I | Column II |
| (i) Mass percentage | (a) `"Number of moles of the solute component"/"Volume of solution in litres"` |
| (ii) Volume percentage | (b) `"Number of moles of a component"/"Total number of moles of all the components"` |
| (iii) Mole fraction | (c) `"Volume of the solute component in solution"/"Total volume of solution" xx 100` |
| (iv) Molality | (d) `"Mass of the solute component in solution"/"Total mass of the solution" xx 100` |
| (v) Molarity | (e) `"Number of moles of the solute components"/"Mass of solvent in kilograms"` |
Define the following modes of expressing the concentration of a solution. Which of these modes are independent of temperature and why?
w/w (mass percentage)
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 :
What is molarity of resulting solution obtained by mixing 8.5 L of 0.5 m urea solution and 500 ml of 2 m urea solution?
3.36 M sulphuric acid solution is 29% H2SO4 calculate the density of the solution.
Calculated the mole fraction of benzene in a solution containing 30% by mass of its is carbon tetrachloride
Calculate the mass percent of benzene (CoH6) and carbon tetrachloride (ccl4) if 22 g of benzene is dissolved in 122 g of carbon tetrachloride.
4.5 g of compound A (MW = 90) was used to make 250 mL of its aqueous solution. The molarity of the solution in M is x × 10−1. The value of x is ______. (Rounded-off to the nearest integer)
A given solution of H2O2 is 30 volumes. Its concentration in terms of molarity is ______.
4 ml of pure A (d = 2.45 gm/ml) was added to 46 ml of B (d = `25.1/23` gm/ml), the molarity of a solution of A in B will be ______, if the density of the final solution is 1.8 gm/ml.
Given: Molar mass of A = 98, Molar mass of B = 46
A 5% solution of \[\ce{Na2SO4.10H2O}\] (MW = 3 22) is isotonic with 2% solution of non- electrolytic, non volatile substance X. Find out the molecular weight of X.
The depression in freezing point of water observed for the same amount of acetic acid, trichloroacetic acid and trifluoroacetic acid increases in the order given above. Explain briefly.
