This set of Engineering Chemistry Multiple Choice Questions & Answers (MCQs) focuses on “Zeolites”.
1. The chemical formula of zeolite is
b) Al2(SO4)3.18 H2O
Explanation: The chemical formula of zeolite is Na2O.Al2O3.xSiO2.yH2O. Zeolites are micro-porous, alumino-silicate minerals commonly used as commercial adsorbents and catalysts.
2. Which of the following is not naturally occurring zeolite?
Explanation: Ca+2 is not naturally occurring zeolite. Na+, Al+3 and Si+4 are some of the naturally occurring zeolites.
3. Natural zeolites are
d) Possess gel structure
Explanation: Natural zeolites are non-porous, amorphous and durable. Natural zeolites form where volcanic rocks and ash layers react with alkaline groundwater.
4. Synthetic zeolites possess higher exchange capacity per unit weight compared to natural zeolites.
Explanation: Synthetic zeolites possess higher exchange capacity per unit weight compared to natural zeolites. Synthetic zeolites are formed by a process of slow crystallization of a silica-alumina gel in the presence of alkalis and organic templates.
5. The exhausted zeolite is reclaimed by treating the bed with a
a) Conc. NaCl
b) Conc. HCl
c) Conc. H2SO4
d) Dil. HCl
Explanation: The exhausted zeolite is reclaimed by treating the bed with conc. NaCl (brine) solution. Zeolites have the potential of providing precise and specific separation of gases including the removal of H2O, CO2 and SO2 from low-grade natural gas streams.
6. Select the incorrect statement from the following option.
a) The capital cost for zeolite process is high
b) The residual hardness in zeolite process is 0-15 ppm
c) The raw water used should be turbid and acidic
d) Automation is possible in zeolite process
Explanation: The raw water used should be non-turbid and non-acidic. All the other options are correct. The capital cost for zeolite process is high and the residual hardness in the zeolite process is 0-15 ppm. Automation is also possible in zeolite process.
7. In zeolite process, the exchange of ___________ takes place.
c) Both cations and anions
d) No ions exchange
Explanation: In the zeolite process, the exchange of only cations takes place. The specific activation modality of most zeolitic catalysts used in petrochemical applications involves quantum-chemical Lewis acid site reactions.
8. The hardness of 1000 litres of a water sample was removed by passing it through a zeolite softener which required 30litres of NaCl solution containing 1.5 gm/L NaCl for regeneration. The hardness of the water sample will be
a) 54.2 ppm
b) 12.9 ppm
c) 45 ppm
d) 38.46 ppm
Explanation: The hardness of the water sample will be 38.46 ppm.
9. Which of the following cannot be used in place of NaCl?
Explanation: NaNO3, KCl and KNO3 can also be used instead of NaCl. But HCl cannot be used in place of NaCl.
10. Natrolite is an example of
a) Synthetic zeolite
b) Natural zeolite
Explanation: Natrolite is an example of natural zeolite. Natural zeolites are non-porous, amorphous and durable. Natural zeolites form where volcanic rocks and ash layers react with alkaline groundwater.
Sanfoundry Global Education & Learning Series – Engineering Chemistry.
To practice all areas of Engineering Chemistry, here is complete set of 1000+ Multiple Choice Questions and Answers.