Arrange the following in:
Increasing acidic property:
ZnO, Na2O2, P2O5, MgO
คำตอบ
(C)
Na2O2 < MgO < ZnO < P2O5
2
Five ml of 8N nitric acid, 4.8ml of 5N hydrochloric acid and a certain volume of 17M sulphuric acid are mixed together and made upto 2 litre. Thirty ml of this acid mixture neutralise 42.9 ml of sodium carbonate solution containing one gram of Na2CO3.10H2O in 100 ml of water. Calculate the amount in gram of the sulphate ions in solution.
คำตอบ
(C)
6.3648 g
3
Bohr Model can explain
คำตอบ
(B)
spectrum of an atom or ion containing one electron only
4
The radius of an atomic nucleus is of the order of
คำตอบ
(B)
10-13 cm
5
Electromangnetic radiation with maximum wavelength is:
คำตอบ
(B)
radiowave
6
Give reasons why the ground state outermost electronic configuration of silicon is:
คำตอบ
C
D
E
7
What is the maximum number of electrons that may be present in all atomic orbitals with principal quantum number 3 and azimuthal quantum number 2?
คำตอบ
10
8
On Mulliken scale, the average of ionization potential and electron affinity is known as _____.
คำตอบ
(C)
Electronegativity
9
Arrange the following in:
Decreasing ionic size:
Mg2+, O2-, Na+, F-
คำตอบ
(B)
O2- > F- > Na+ > Mg2+
10
Arrange the following in:
Increasing first ionisation potential :
Mg, Al, Si, Na
คำตอบ
(B)
Na < Al < Mg < Si
11
All molecules with polar bonds have dipole moment.
คำตอบ
(B)
FALSE
12
SnCl2 is a non-linear molecule
คำตอบ
(A)
TRUE
13
The molecule having one unpaired electron is
คำตอบ
(A)
NO
14
How many sigma bonds and how many pi-bonds are present in a benzene molecule?
คำตอบ
(E)
12 \(\sigma\), 3 \(\pi\)
15
Kinetic Energy of a Molecule is zero at 0oC.
คำตอบ
(B)
FALSE
16
A gas in a closed container will exert much higher pressure due to gravity at the bottom than at the top.
คำตอบ
(B)
FALSE
17
Rate of diffusion of a gas is
คำตอบ
(C)
inversely proportional to the square root of its molecular weight.
18
Calculate the root mean square velocity of ozone kept in a closes vessel at 20oC and 82 cm mercury pressure.
คำตอบ
(B)
3.9 x 10^4 cm/sec
19
Sodium dissolved in liquid ammonia conducts electricity because ________.
คำตอบ
(D)
of solvated electrons.
20
Hydrogen gas will not reduce
คำตอบ
(D)
heated aluminium oxide
21
Molecular formula of Glauber's salt is:
คำตอบ
(D)
Na2SO4.10H2O
22
The oxide that gives hydrogen peroxide on treatment with a dilute acid is
คำตอบ
(B)
Na2O2
23
Write down the balanced equations for the reaction when:
Calcium phosphate is heated with a mixture of sand and carbon;
