How much time (in hours) would it take to distribute one Avogadro number of wheat grains, if 1020 grains are distributed each second?
0.1673
1.673
16.73
167.3
At 25°C, at 5% aqueous solution of glucose (molecular weight = 180g mol-1) is isotonic with a 2% aqueous solution containing and unknown solute. What is the molecular weight of the unknown solute?
60
80
72
63
200 mL of water is added to a 500 mL of 0.2 M solution. What is the molarity of this diluted solution?
0.5010M
0.2897M
0.7093
0.1428
When 200 mL of aqueous solution of HCl (pH = 2) is mixed with 300 mL of an aqueous solution of NaOH (pH = 12) the pH of the resulting mixture is
10
2.7
4.0
11.3
D.
11.3
Concentration of HCl solution = 1 × 10-2
Millimoles of HCl solution = 200 × 1 × 10-2 = 2
Similarly,
Millimoles of NaOH solution = 300 × 1 × 10-2 = 3
Concentration of the resultant solution
=
=
= 0.2 × 10-2
[OH-] = 0.2 × 10-2
pOH = -log[OH-] = -log [2 × 10-3] = +2.70
Therefore, pH of the resulting mixture = 14 - 2.70 = 11.3
The percentage of an element M is 53 in its oxide of molecular formula M2O3. Its atomic mass is about
45
9
27
36
The pH of a solution obtained by mixing 50 mL of 1 N HCl and 30 mL of 1 N NaOH is [log 2.5 = 0.3979]
12.042
0.6021
0.3979
3.979
How much of sulphur is present in an organic compound, if 0.53 g of the compound gave 1.158 g of BaSO4 on analysis ?
10%
20%
30%
15%
Law of multiple proportions is illustrated by one of the following pairs :
N2O and NO
H2S and SO2
NH3 and Na2O
BeO and BeCl2
Avogadro's hypothesis states that :
the ideal gas consists of a large number of small particles called molecules
under the same conditions of temperature and pressure equal volumes of gases contain the same number of molecules
volume of a definite quantity of gas at constant pressure is directly proportional to absolute temperature
a given mass of gas at constant pressure is directly proportional to absolute temperature
If 117 gm NaCl is dissolved in 1000 g of water the concentration of the solution is said to be :
2 molar
2 molal
1 normal
1 molal