Advertisements
Advertisements
Question
When KOH solution is added to potassium dichromate solution the colour of solution
changes to yellow, because _______
(A) chromate ion changes to dichromate ion
(B) dichromate ion changes to chromate ion
(C) oxidation number of chromium changes from + 6 to + 4
(D) oxidation number of chromium changes from + 4 to +6
Advertisements
Solution
dichromate ion changes to chromate ion.
APPEARS IN
RELATED QUESTIONS
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 \[\ce{Co(NO3)2 * 6H2O}\] in 4.3 L of solution.
Calculate the mass of urea (NH2CONH2) required in making 2.5 kg of 0.25 molal aqueous solution.
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 Molarity (M).
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 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.
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.
What is molal depression constant? Does it depend on nature of the solute?
Molality of a solution relates the ____________.
Which of the following is a quantitative description of the solution?
4.0 g of NaOH is dissolved in 100 ml solution. The normality of the solution is ____________.
Mole fraction of the solute in a 1.00 molal aqueous solution is ____________.
200 ml of water is added to 500 ml of 0.2 M solution. What is the molarity of this diluted solution?
If N/10 50 ml H2SO4, N/3 30 ml HNO3, N/2 10 ml HCl is mixed and solution is made to 1 L. Then normality of the resultant solution is:
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:
The number of moles of NaCl in 3 litres of 3 M solution is ____________.
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 ______.
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?
m (Molality)
What is the ratio of mass of an electron to the mass of a proton?
The number of electrons involved in the reduction of one nitrate ion to hydrazine 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?
A given solution of H2O2 is 30 volumes. Its concentration in terms of molarity 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]
