Advertisements
Advertisements
प्रश्न
A sample of 12 M Concentrated hydrochloric acid has a density 1.2 M gL-1 calculate the molality.
Advertisements
उत्तर
Given:
Molarity = 12 M HCl
density of solution = 1.2 g L-1
In 12 M HCl solution, there are 12 moles of HCl in 1 litre of the solution.
Molality = `"no of moles of solute"/"mass of solvent (in kg )"`
Calculate mass of water(solvent)
mass of 1 litre HCl solution = density × volume
= 1.2 × gmL-1 × 1000 mL = 1200 g
mass of HCl = no. of moles of HCl × molar mass of HCl
= 12 mol × 36.5 g mol-1
= 438 g.
mass of water = mass of HCl solution – mass of HCl
mass of water = 1200 – 438 = 762 g
molality(m) = `12/0.762` = 15.75 m
APPEARS IN
संबंधित प्रश्न
Calculate (a) molality (b) molarity and (c) mole fraction of KI if the density of 20% (mass/mass) aqueous KI is 1.202 g mL−1.
Define mass percentage.
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?
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.
The volume of 4 N HCl and 10 N HCl required to make 1 litre of 6 N HCl are ____________.
Which of the following units is useful in relating concentration of solution with its vapour pressure?
Define the following modes of expressing the concentration of a solution. Which of these modes are independent of temperature and why?
m (Molality)
Match List-I with List-II:
| List-I | List-II |
| A. ppm | I. molL-¹ |
| B. Molarity | II. No units |
| C. Molality | III. Independent of temperature |
| D. Mole fraction | IV. Very dilute solutions |
Choose the correct answer from the options given below:
The unit of ebullioscopic constant 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]
