General Science Chemistry MCQs
Chemistry Objective (Multiple Choice) General Knowledge Questions & Answers for SSC-CGL, UPPSC, UPSC, NDA, CDS and UPSC Civil Services Prelims Examination
21. What is the unit of Stress?
[A] N/m
[B] Kg/m
[C] Nm
[D] It has no units
Show Answer
Correct Answer: A [N/m]
Notes:
If an external force F is applied on the area A of a body then, Stress is given by Force/Area Units of Stress: S.I unit: N / m C.g.s unit: dyne / cm
22. What is the maximum stress after which the wire breaks called as?
[A] Tensile strength
[B] Shear strength
[C] Bulk strength
[D] Hooke’s strength
Show Answer
Correct Answer: A [Tensile strength]
Notes:
The maximum stress after which the wire begin to flow and breaks, is called breaking stress or tensile strength. The force by application of which the wire breaks is called the breaking force.
23. What is the ratio of normal stress to the volumetric strain within the elastic limits is called as?
[A] Bulk Modulus
[B] Young Modulus
[C] Modulus of Rigidity
[D] None of the above
Show Answer
Correct Answer: A [Bulk Modulus]
Notes:
The ratio of normal stress to the volumetric strain within the elastic limits is called as Bulk modulus. It is denoted by K.
24. Which among the following acids is generally used as a first hand test to judge whether a metal is Gold or not?
[A] Sulfuric Acid
[B] Nitric Acid
[C] Hydrochloric Acid
[D] Sulfurous Acid
Show Answer
Correct Answer: B [Nitric Acid]
Notes:
The funda is that when a small drop of a strong acid, such as nitric acid, is put onto the metal’s surface, most metals fizz or bubble, whilst precious metals (Gold or Platinum not silver) are unaffected.
25. What happens to the non-metallic character of elements in the p-block of the periodic table?
[A] non-metallic character decreases down the group
[B] non-metallic character increases down the group
[C] No fix pattern
[D] None
Show Answer
Correct Answer: A [non-metallic character decreases down the group]
Notes:
The non-metallic character of elements decreases down the group. In fact, the heaviest element in each p-block group is the most metallic in nature.
26. What is the general outer electron configuration of Group 13 elements?
[A] ns2 np2
[B] ns2
[C] ns2 np1
[D] ns2 np3
Show Answer
Correct Answer: C [ns2 np1]
Notes:
ns2 np1
27. Which of these is NOT an allotropic form of carbon?
[A] Diamond
[B] Graphite
[C] Fullerene
[D] None of the above
Show Answer
Correct Answer: D [None of the above]
Notes:
Carbon exhibits many allotropic forms; both crystalline as well as amorphous. Diamond and graphite are two well-known crystalline forms of carbon. In 1985, third form of carbon known as fullerenes was discovered.
28. Which of the following alkaline earth metals is the rarest in the earth crust?
[A] Calcium
[B] Strontium
[C] Radium
[D] Beryllium
Show Answer
Correct Answer: C [Radium]
Notes:
Of the alkaline earth metals calcium and magnesium rank fifth and sixth in abundance respectively in the earth’s crust. Strontium and barium have much lower abundances. Beryllium is rare and radium is the rarest of all comprising only 10–10 per cent of igneous rocks.
29. What is water gas?
[A] mixture of CO and H2
[B] mixture of CO and H2O
[C] mixture of CO2 and H2
[D] Carbon mono-oxide
Show Answer
Correct Answer: A [mixture of CO and H2]
Notes:
The mixture of CO and H2 produced is known as water gas or synthesis gas.
30. Which of the following catalyst is used generally during the hydrogenation of Alkenes?
[A] Platinum
[B] Palladium
[C] Nickel
[D] All of the above
Show Answer
Correct Answer: D [All of the above]
Notes:
Dihydrogen gas adds to alkenes and alkynes in the presence of finely divided catalysts like platinum, palladium or nickel to form alkanes.
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