Learn more about the properties, composition, and structure of substances (elements and compounds) with these Chemistry questions and answers. This Test can be used by students preparing for Chemistry in JAMB, WAEC, NECO or Post UTME.
0.05
10.80
10.00
0.10
Correct answer is D
m = Mm×Q96500n
where Q = IT
M = Mm × Q96500n
where m = mass
Mm = Molar mass
Q = Quantity of electricity
n = number of change= +1
MMm = mole = massMolarmass
MMm = Q96500n
= 965096500n × 1
= 110 = 0.1mol
Tin is unaffected by air at ordinary temperature due to its?
Low melting point
Weak electropositive character
High boiling point
White lustrous appearance
Correct answer is A
Tin has a melting point of 232° which enables it to be unaffected by air at ordinary temperature coupled with the fact that it also helps in making a good metal for alloying.
Tin is relatively unaffected by both water and oxygen at room temperature due to its low melting point. It does not rust, corrode, or react in any other way. This explains one of its major uses: as a coating to protect other metals.
The shape of ammonia molecules is
trigonal planar
octahedral
square planar
tetrahedral
Correct answer is A
Ammonia = NH3
It has three bonds of hydrogen to the Nitrogen.
22688Ra → x86Rn + alpha particle
226
220
227
222
Correct answer is D
22688Ra → x86Rn + 42He
42He = alpha particle
considering the summation of the mass number
226 = x + 4
x = 226 - 4
x = 222