1. The kinematic viscosity of the oil can be calculated by ___________
a) V = ŋ+ρ
b) V = ŋ/ρ
c) V = ŋ – ρ
d) V = ŋ*ρ
Explanation: The kinematic viscosity means the viscosity that determines the kinematic energy of the liquid that means it determines the speed of the oil. So, the kinematic viscosity of the oil is given by V=ŋ/ρ, where ŋ = absolute viscosity of the oil and ρ = density of the oil.
2. Acid number of a lubricating oil is _________ required to neutralise all acidic constituents of 1 g of oil.
a) Mgs of KOH
b) Mgs of K2SO4
c) Mgs of NaOH
d) Mgs of Na2SO4
Explanation: Acid number of lubricating oil is defined as the mgs of KOH required to neutralise the all acidic constituents of 1g of oil. So, it is also called as the neutralisation number.
3. The fatty oils mostly constitute _________
a) Glycerine
b) Glycol
c) Ethanol
d) Glycerol
Explanation: The fatty acids constitute most of the part with glycerol. It also has the esters of higher fatty acids as the next major constituents. In some cases, we can also observe that a notable amount of free acids are also present in fatty acids.
4. The acid content ______ with time.
a) Decreases
b) Increases
c) Remains constant
d) Becomes zero
Explanation: The acid content will be increasing with time because as the time goes on the chemical reaction takes place and the number of H+ ions increases with increase in time. So, the acid content also increases with time.
5. Periodic determination of acid number is useful to indicate the progress of ________
a) Oxidation number
b) Reduction number
c) Acidic number
d) Neutralisation number
Explanation: The periodic determination of the acid number is useful to indicate the progress of oxidation number. The age of the oil is determined by the increase in acid number with time due to hydrolysis with moisture.
6. The acid value of the lubricating oil is must be less than _______
a) 7
b) 0.7
c) 1
d) 0.1
Explanation: The acid value of the lubricating oils must be always less than that of the 0.1. It is because the acid value changes the progress of the oxidation number and hydrolysis rate and moisture content. Based on which we have to replace the lubricating oil.
7. The unblended petroleum oils must have ______ neutralisation values.
a) Very high
b) Very low
c) Negligible
d) Zero
Explanation: The neutralisation values of the unblended petroleum oils will be very low. The neutralisation values of the unblended petroleum oils ranges from 0.02 to 0.1. Values higher than this indicate faulty refining.
8. Compounded oils have higher neutralisation values.
a) True
b) False
Explanation: The Compounded oils are also called as blended oils. The unblended oils have very less neutralisation number. It is about 0.02 to 0.1. The blended or compounded oils have very high neutralisation number.
9. The higher values of blended oils is because of the presence of ___________
a) Catalyst
b) Salts
c) Additives
d) Reagents
Explanation: The high values of neutralisation of blended oils are because of the presence of the additives. The additives present in the oiliness carriers, oxidation and corrosion inhibitors, etc.
10. The neutralisation number is increased due to _________
a) Pureness
b) Contamination
c) Hydrolysis
d) Catalysis
Explanation: The neutralisation number is increased due to the contamination as the oil is used. Examples are sulphur dioxide on combustion of sulphur, carbondioxide on combustion of carbon or present in the atmosphere.