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.
Which of the following gases is alkaline?
NO\(_{2}\)
CO\(_{2}\)
NH\(_{3}\)
N\(_{2}\)O
Correct answer is C
Alkaline gases are any gaseous compounds that form an alkali (or basic) solution with a pH greater than 7 when dissolved in water. Ammonia is the most common alkaline gas
Graphite is used as a dry lubricant due to the presence of
mobile electrons
free electrons
octahedral structures
layered structures
Correct answer is D
Graphite is an excellent dry lubricant. This is because its layered structure allows one layer to slide over another easily. It is non-volatile and not sticky.
1.0 atm
0.1 atm
9.0 atm
0.9 atm
Correct answer is B
Partial pressure is found by Dalton's Law:
Px = PTotal ( nx / nTotal )
where
Px = partial pressure of gas x
PTotal = total pressure of all gases
nx = number of moles of gas x
nTotal = number of moles of all gases
Step 1
Find PTotal
Standard pressure is 1 atm.
Step 2
Add up the number of moles of the component gases to find nTotal
nTotal = noxygen + nnitrogen
nTotal = 100 + 900
nTotal =1000cm3
Step 3
Now you have all the information needed to plug the values into the equation and solve for Poxygen
P-oxygen = PTotal ( n-oxygen / nTotal )
oxygen = 1 atm ( 100 / 1000 )
oxygen= 0.1atm
Which of the following acids would form normal salt only?
Tetraoxosulphate(VI) acid
Trioxonitrate(V) acid
Tetraoxophosphate(V) acid
Trioxosulphate(IV) acid
Correct answer is A
Normal salts are formed when all the replaceable hydrogen ions in the acid have been completely replaced by metallic ions
a basic oxide
a reducing agent
an acidic oxide
an oxidizing agent
Correct answer is C
Silicon dioxide is an acidic oxide. It will react with strong bases to form silicate salts, SiO\(_{2}\) is acidic oxide because Si is non-metal. Oxides of non-metals are acidic in nature.