How many grams of the concentrated nitric solution should be used to prepare 250 mL o 2.0M HNO3 ? The concentrated acid is 70% HNO3.
45.0 g conc. HNO3
90.0 g conc. HNO3
70.0 g conc. HNO3
70.0 g conc. HNO3
6.02 x 1020 molecules of urea are present in 100 mL of its solution. The concentration of solution is
0.02 M
0.01 M
0.001 M
0.001 M
Mole fraction of the solute in a 1.00 molal aqueous solution is
0.0177
0.0344
1.7700
1.7700
Which one of the following statements is not true?
Concentration of DO below 6 ppm is good for the growth of fish
Clean water would have a BOD value of less than 5 ppm
Oxides of sulphur, nitrogen and carbon are the most widespread air pollutant
Oxides of sulphur, nitrogen and carbon are the most widespread air pollutant
If Avogadro number NA, changed from 6.022 x 1023 mol-1 this would change
the definition of mass in units of grams
the mass of one mole of carbon
the ratio of chemical species to each other in the balanced equation
the ratio of chemical species to each other in the balanced equation
20.0 g of a magnesium carbonate sample decomposes on heating to give carbon dioxide and 8.0 g magnesium oxide. What will be the percentage purity of magnesium carbonate in the sample? (Atomic weight of Mg =24)
75
96
60
60
What is the mass of precipitate formed when 50 mL of 16.9% solution of AgNO3 is mixed with 50 mL of 5.8% NaCl solution?
(Ag = 107.8, N = 14, O = 16, Na = 23, Cl = 35.5)
28 g
3.5 g
7 g
7 g
What is the mole fraction of the solute in a 1.00 m aqueous solution?
0.177
1.770
0.0354
0.0354
The number of water molecules is maximum in
18 molecules of water
1.8 g of water
18 g of water
18 g of water
D.
18 g of water
Mole is the biggest unit to measure the number of molecules/atom/ions.
therefore,
1 mole of water contains molecules = 6.02 x 1023
therefore, 18 moles of water contain molecules
Which has the maximum number of molecules among the following?
44 g CO2
48 g O3
8 g H2
8 g H2