What is the significant figures in 0.001620?
Four
Six
Three
Two
The number of water molecules present in a drop of water (Volume 0.0018 mL) at room temperature is
6.023×1019
1.084×1018
4.80×1017
6.023×1023
The molecular weight of O2 and SO2 are 32 and 64 respectively. At 15oc and 150mm Hg pressure, 1L of O2 contains 'N' molecules. The number of molecules in 2L of SO2 under the same conditions of temperature and pressure will be
N/2
N
2N
4N
Boron has two stable isotopes, 10B(19%) and 11B (81%). Calculate average atomic weight of Boron in the periodic table?
10.8
10.2
11.2
10.0
The total number of electrons present in 18 ml of water (density of water is 1 gml-1) is
6.02×1023
6.02×1022
6.02×1025
6.02×1024
An element, x has the following isotopic composition .
The weighted average atomic mass of the naturally occurring element x is closet to
201u
202u
199u
200u
Which has maximum number of molecules ?
7g N2
2g H2
16g NO2
16g O2
0.24 g of a volatile gas, upon vaporization, gives 54mL vapour at NTP. What will be the vapour density of the substance? (Density of H2 = 0.089)
95.93
59.93
95.39
39.93
