N2(g) + 3H2(g) ↔ 2NH3(g) ΔH = -90 kJ
In the equation above, the yield of ammonia can be decreased by
increasing the pressure
removing the ammonia as it is formed
increase the temperature
adding a catalyst
Correct answer is C
No explanation has been provided for this answer.
A dense white fume is formed when ammonia gas reacts with
O2(g)
H2(g)
Cl2(g)
HCl(g)
Correct answer is D
No explanation has been provided for this answer.
Al2N
Al2N2
AlN
Al2N3
Correct answer is C
No explanation has been provided for this answer.
The density of a certain gas is 1.98gdm-3 at s.t.p. What is the molecular mas of the gas?
44.0 g
54.0 g
26.0 g
31.0 g
Correct answer is A
Density = mass/volume
∴ 1.98 = molecular mass/22.4
molecular mass = 1.98 * 22.4 = 44.35 ≅ 44.05
What is the valence shell electron configuration of the element with atomic number 17?
1s2 2s2 2p6 3s2 3p4
1s2 2s2 2p6 3s2 3p5
2s2 2p6
3s2 3p5
Correct answer is D
It's important to take note of "valence shell" used in the presentation of the question.
Hence; Option D carries the answer as specified in the question.