Advertisements
Advertisements
प्रश्न
Calculate the molarity of a solution of ethanol in water in which the mole fraction of ethanol is 0.040 (assume the density of water to be one).
Advertisements
उत्तर
Mole fraction of C2H5OH `=("Number of moles of ""C"_2"H"_5"OH")/"Number of moles of solution"`
`0.040="n"_("C"_2"H"_5"OH")/("n"_("C"_2"H"_5"OH")+"n"_("H"_2"O"))` .......(1)
Number of moles present in 1 L water:-
`"n"_("H"_2"O") = (1000 " g")/(18 " g"" mol"^-1)`
`"n"_("H"_2"O") = 55.55 " mol"`
Substituting the value of `"n"_("H"_2"O")` in equation (1),
`"n"_("C"_2"H"_5"OH")/("n"_("C"_2"H"_5"OH")+55.55)=0.040`
`"n"_("C"_2"H"_5"OH") = 0.040 "n"_("C"_2"H"_5"OH") + (0.040)(55.55)`
`0.96" n"_("C"_2"H"_5"OH") = 2.222 " mol"`
`"n"_("C"_2"H"_5"OH") = 2.222/0.96" mol"`
`"n"_("C"_2"H"_5"OH") = 2.314" mol"`
∴ Molarity of solution `=(2.314" mol")/(1 "L")`
= 2.314 M
संबंधित प्रश्न
Explain the term mole fraction.
Solve the following problem:
Write the following number in ordinary decimal form:
0.011 × 10−3
Solve the following problem:
Write the following number in ordinary decimal form:
14.3 × 10−2
Solve the following problem:
Perform the following calculation. Round off your answer to two digits.
`(1.4xx10^9)/((2.77xx10^3)(3.76xx10^5))`
Solve the following problem:
Perform the following calculation. Round off your answer to three digits.
`((9.28xx10^9)(9.9xx10^-7))/((511)(2.98xx10^-6))`
Solve the following problem:
Your laboratory partner was given the task of measuring the length of a box (approx 5 in) as accurately as possible, using a metre stick graduated in milimeters. He supplied you with the following measurements:
12.65 cm, 12.6 cm, 12.65 cm, 12.655 cm, 126.55 mm, 12 cm.
State which of the measurements you would accept, giving the reason.
Solve the following problem:
What weight of calcium oxide will be formed on heating 19.3 g of calcium carbonate?
(At. wt.: Ca = 40; C = 12; O = 16)
Name the process associated with the following
A drop of ink placed on the surface of water contained in a glass spreads throughout the water.
What are the favourable qualities given to gold when it is alloyed with copper or silver for the purpose of making ornaments?
Calculate the mass of sodium sulphate required to prepare its 20% (mass percent) solution in 100g of water?
If 500 mL of a 5 M solution is diluted to 1500 mL, what will be the molarity of the solution obtained?
If the concentration of glucose \[\ce{(C6H12O6)}\] in blood is 0.9 g L–1, what will be the molarity of glucose in blood?
Which of the following solutions have the same concentration?
(i) \[\ce{20 g of NaOH in 200 mL of solution}\]
(ii) \[\ce{0.5 mol of KCl in 200 mL of solution}\]
(iii) \[\ce{40 g of NaOH in 100 mL of solution}\]
(iv) \[\ce{20 g of KOH in 200 mL of solution}\]
An aqueous KCl solution of density 1.20 g mL-1 has a molality of 3.30 mol kg-1. The molarity of the solution in mol L-1 is ______. (Nearest integer)
What quantity (in mL) of a 45% acid solution of a monoprotic strong acid must be mixed with a 20% solution of the same acid to produce 800 mL of a 29.875% acid solution?
Molarity of liquid HCl will be if the density of the solution is 1.17 g/cc.
The molarity of urea (molar mass 60 g mol−1) solution by dissolving 15 g of urea in 500 cm3 of water is ______.
Molarity is ______.
