STS - Student Testing Service
ONLINE TEST INFORMATION MUST FOLLOW STEPS First Submit Your Detail below (9)No Negative Marks Online test divided into 10 portion each contain 20 mcqs No Back system after you go to next portion. If page was refresh then your all mcqs answer removed. TIMING 8:00 am to 8:00 pm then link will be removed Time duration 150 minutes or 2:30 hour Please use android mobile or laptop or pc Ios ( iphone is not supported )
- 1.
An insulated tube with a movable piston at one end had 500j of heat added to it if during experiement the piston moves and does 75j of work on the atmosphere what change in energy of tube system ?
- A.
775j
- B.
500j
- C.
425
- D.
-75
- E.
-425
Correct Answer
C. 425Explanation
In this experiment, 500J of heat is added to the insulated tube system. The movable piston then does 75J of work on the atmosphere. According to the first law of thermodynamics, the change in energy of the system is equal to the heat added minus the work done by the system. Therefore, the change in energy of the tube system is 500J - 75J = 425J.Rate this question:
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- 2.
The oxidation state of Nitrogen is most negative in which of the following compound ?
- A.
N2
- B.
N2O
- C.
NO2
- D.
NO3
- E.
NH3
Correct Answer
E. NH3Explanation
The oxidation state of Nitrogen is most negative in NH3 because in NH3, Nitrogen has a -3 oxidation state. In N2, Nitrogen has a 0 oxidation state as it is in its elemental form. In N2O, Nitrogen has a +1 oxidation state. In NO2, Nitrogen has a +4 oxidation state. In NO3, Nitrogen has a +5 oxidation state. Therefore, NH3 has the most negative oxidation state of Nitrogen.Rate this question:
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- 3.
All combustion reactions are ........Reactions?
- A.
Endothermic
- B.
Exothermic
- C.
Photo Chemical
- D.
Rearrangment
Correct Answer
B. ExothermicExplanation
Combustion reactions are exothermic because they release heat and light energy. During combustion, a fuel reacts with oxygen to produce carbon dioxide, water, and heat. This release of heat energy is what makes combustion reactions exothermic.Rate this question:
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- 4.
The anode at is electrode at which ........process occurs?
- A.
Oxidation
- B.
Reduction
- C.
Self Redox Reaction
- D.
None of these
Correct Answer
A. OxidationExplanation
The anode is the electrode where oxidation occurs. Oxidation is a chemical process in which a substance loses electrons, resulting in an increase in its oxidation state. At the anode, electrons are released, causing the substance to be oxidized. Therefore, the correct answer is "Oxidation."Rate this question:
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- 5.
For a gas obeying boyles law ,if pressure is doubled than volume become ?
- A.
Half
- B.
Double
- C.
4 time increase
- D.
8 time increase
Correct Answer
A. HalfExplanation
According to Boyle's Law, the pressure and volume of a gas are inversely proportional at constant temperature. When the pressure is doubled, the volume of the gas will be halved. This can be explained by the fact that increasing the pressure of a gas compresses its particles closer together, resulting in a decrease in volume. Therefore, the correct answer is "Half."Rate this question:
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- 6.
Which molecule has zero dipole movement?
- A.
NH3
- B.
SO2
- C.
H2O
- D.
CO2
Correct Answer
D. CO2Explanation
CO2 has zero dipole moment because it is a linear molecule with the same atoms (two oxygen atoms) on both sides of the central carbon atom. The oxygen atoms have equal and opposite dipole moments, canceling each other out. This results in a symmetrical distribution of charge, making CO2 a nonpolar molecule with no net dipole moment.Rate this question:
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- 7.
The percent composition of an unknown element X in CH3X is 32%.which of the following is element X?
- A.
H
- B.
F
- C.
Na
- D.
Cl
- E.
Li
Correct Answer
E. LiExplanation
The correct answer is Li. This is because the percent composition of element X in CH3X is given as 32%. Since Li is the only option with a chemical symbol that starts with the letter "L", it is the most likely element X in this compound.Rate this question:
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- 8.
How much NaOH must be added to make 200mL of a 1M NaOH solution?
- A.
80
- B.
40
- C.
16
- D.
8
Correct Answer
A. 80Explanation
To make a 1M NaOH solution, the molarity is given as 1M, which means there is 1 mole of NaOH in 1 liter of solution. Since we want to make a 200mL solution, we need to calculate the amount of NaOH needed. Using the formula Molarity = Moles/Volume, we rearrange the formula to find the moles of NaOH needed. Moles = Molarity x Volume. Plugging in the values, we get Moles = 1M x 0.2L = 0.2 moles. To convert moles to grams, we use the molar mass of NaOH which is 40g/mol. Therefore, the amount of NaOH needed is 0.2 moles x 40g/mol = 8g. Hence, the correct answer is 80.Rate this question:
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- 9.
A process involving no Heat exchange is known as?
- A.
Isothermal process
- B.
Adiabatic process
- C.
Isometric process
- D.
Isobaric process
Correct Answer
A. Isothermal processExplanation
An isothermal process is a process in which there is no exchange of heat with the surroundings. This means that the system remains at a constant temperature throughout the process. In an isothermal process, the heat added to the system is equal to the work done by the system, resulting in no net change in internal energy. Therefore, an isothermal process involves no heat exchange.Rate this question:
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- 10.
Which of the following is Formula for a noncyclic saturated hydrocarbon?
- A.
C7H12
- B.
C7H18
- C.
C7H14
- D.
C7H16
Correct Answer
D. C7H16Explanation
The formula C7H16 represents a noncyclic saturated hydrocarbon. This is because the formula indicates that there are 7 carbon atoms (C7) and 16 hydrogen atoms (H16), which satisfies the requirements for a saturated hydrocarbon. A saturated hydrocarbon is a type of organic compound that contains only single bonds between carbon atoms and is fully saturated with hydrogen atoms. In this case, the formula indicates that there are no double or triple bonds between carbon atoms, making it a noncyclic saturated hydrocarbon.Rate this question:
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- 11.
When electron jumps from n=6 to n=2 then belongs to ......series?
- A.
Layman Series
- B.
Balmar Series
- C.
Bracket Series
- D.
Pfund Series
Correct Answer
B. Balmar SeriesExplanation
The electron jumping from n=6 to n=2 belongs to the Balmer series. The Balmer series refers to the set of spectral lines in the visible region of the electromagnetic spectrum that are emitted or absorbed when an electron transitions from a higher energy level to the second energy level (n=2) in a hydrogen atom. This series is important in understanding atomic structure and has been extensively studied in spectroscopy.Rate this question:
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- 12.
The oxidation state of Fe in K4[Fe(CN)6?
- A.
+3
- B.
+4
- C.
0
- D.
+2
- E.
-2
Correct Answer
D. +2Explanation
In the compound K4[Fe(CN)6], the overall charge of the compound is 0. Since potassium (K) has a charge of +1, the total charge contributed by potassium is +4. The cyanide ion (CN) has a charge of -1, so the total charge contributed by cyanide is -6. To balance the charges, the iron (Fe) ion must have a charge of +2. Therefore, the oxidation state of Fe in K4[Fe(CN)6] is +2.Rate this question:
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- 13.
The colour of phenolphthane in Basic medium ?
- A.
Red
- B.
Yellow
- C.
Blue
- D.
Pink
- E.
Colourless
Correct Answer
D. PinkExplanation
In a basic medium, phenolphthalein turns pink. This is because phenolphthalein is a pH indicator that changes color depending on the acidity or basicity of the solution it is in. In basic solutions, phenolphthalein becomes pink due to the presence of hydroxide ions (OH-) which react with the indicator molecule, causing it to change color. Therefore, the correct answer is pink.Rate this question:
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- 14.
How many pi Bond are present in N2?
- A.
2
- B.
3
- C.
No Pi bond
- D.
1
Correct Answer
A. 2Explanation
The correct answer is 2 because N2 molecule consists of a triple bond between two nitrogen atoms. A triple bond consists of one sigma bond and two pi bonds. Therefore, there are two pi bonds present in N2.Rate this question:
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- 15.
When a solution its pH is 3.2 then what will be its PoH .?
- A.
5.8
- B.
6.8
- C.
9.8
- D.
10.8
- E.
Same
Correct Answer
D. 10.8Explanation
The pH and pOH of a solution are related by the equation pH + pOH = 14. Since the pH of the solution is given as 3.2, we can subtract this value from 14 to find the pOH. 14 - 3.2 = 10.8. Therefore, the pOH of the solution is 10.8.Rate this question:
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- 16.
The Geometry Of NH3 is?
- A.
Planner Trigonal
- B.
Trigonal pyramidal
- C.
Tetrahydral
- D.
Bent angular
Correct Answer
B. Trigonal pyramidalExplanation
The correct answer is trigonal pyramidal. In NH3 (ammonia), there are three bonding pairs and one lone pair of electrons around the central nitrogen atom. This arrangement leads to a pyramid-like shape, with the three hydrogen atoms positioned at the base and the lone pair at the apex. The bond angles between the hydrogen atoms are slightly less than 109.5 degrees, which is the ideal tetrahedral angle. Therefore, the geometry of NH3 is trigonal pyramidal.Rate this question:
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- 17.
Balmer series Contain .......region of Light?
- A.
Visible
- B.
Ultraviolet
- C.
Infrared
- D.
For infrared
Correct Answer
A. VisibleExplanation
The Balmer series is a series of spectral lines in the emission spectrum of hydrogen. It corresponds to transitions between energy levels in the hydrogen atom where the electron jumps to or from the second energy level. These transitions result in the emission of visible light. Therefore, the Balmer series contains the visible region of light.Rate this question:
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- 18.
Rectified sprit contain how many percentage of Alcohol?
- A.
4%
- B.
11%
- C.
85%
- D.
90%
- E.
99.99%
Correct Answer
C. 85%Explanation
Rectified spirit is a highly concentrated form of alcohol that is purified through a distillation process. It typically contains a high percentage of alcohol, often around 85%. This makes it suitable for various industrial and medical uses, as well as for making alcoholic beverages. The other options provided, such as 4%, 11%, 90%, and 99.99%, are not as accurate because they do not reflect the high concentration typically found in rectified spirit.Rate this question:
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- 19.
Removal of Hydrogen and Water this reaction known as?
- A.
Hydrogenation
- B.
Halogenation
- C.
Both
- D.
Hydrohalogenation
- E.
All
Correct Answer
D. HydrohalogenationExplanation
Hydrohalogenation is the correct answer because it involves the removal of both hydrogen and water in a chemical reaction. This process typically occurs when a hydrogen halide (such as HCl or HBr) reacts with an alkene or alkyne, resulting in the addition of a halogen atom and a hydrogen atom to the carbon-carbon double or triple bond. Hence, hydrohalogenation is the appropriate term to describe this reaction.Rate this question:
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- 20.
Which of the following is Not Isotope of Hydrogen ?
- A.
Dueterium
- B.
Protium
- C.
Uranium
- D.
Tritium
- E.
C&D both
Correct Answer
C. UraniumExplanation
Uranium is not an isotope of hydrogen. Isotopes of hydrogen include deuterium, protium, and tritium. Uranium is a separate element and is not related to hydrogen isotopes.Rate this question:
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- 21.
Coke is produced from bitumeious coal by
- A.
Cracking
- B.
Synthesis
- C.
Substitution
- D.
Destructive Destillation
- E.
Filteration
Correct Answer
D. Destructive DestillationExplanation
Destructive distillation is the process used to produce coke from bituminous coal. In this process, coal is heated in the absence of air, causing it to break down into various by-products, including coke. This method is commonly used in the production of coke as it allows for the separation of valuable components such as coal gas, coal tar, and coke.Rate this question:
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- 22.
Heating phenol with Zn will yeilds?
- A.
Benzen
- B.
Benzoic Acid
- C.
Phenoxide acid
- D.
Chloro ethane
- E.
Cyclohexane
Correct Answer
A. BenzenExplanation
Heating phenol with Zn will yield benzene. This is because Zn acts as a reducing agent and removes the hydroxyl group (-OH) from phenol, resulting in the formation of benzene.Rate this question:
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- 23.
Formaldehyde +Ethyle Alcohol ..........product will Form?
- A.
Oxime
- B.
Formic acid
- C.
Ethonic acid
- D.
.Hemiacetal
- E.
NONE
Correct Answer
D. .HemiacetalExplanation
The reaction between formaldehyde and ethyl alcohol can result in the formation of a hemiacetal. A hemiacetal is formed when an alcohol group reacts with an aldehyde group, resulting in the formation of a new carbon-oxygen bond. In this case, the formaldehyde acts as the aldehyde group and ethyl alcohol acts as the alcohol group. Therefore, the correct answer is hemiacetal.Rate this question:
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- 24.
Which of the following factors has no effect on Boiling Point?
- A.
Pressure
- B.
Intermolecular forces
- C.
Amount of liquid
- D.
Impurties
- E.
None
Correct Answer
C. Amount of liquidExplanation
The amount of liquid does not have an effect on boiling point because boiling point is determined by the temperature at which the vapor pressure of the liquid equals the atmospheric pressure. The amount of liquid does not affect this equilibrium condition.Rate this question:
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- 25.
Yeast Can be used to convert simple sugar to .......?
- A.
Ethonoic acid +O2
- B.
Ethyle Alcohol +CO2
- C.
Ethanol +O2
- D.
Starch +Carbohydrate
- E.
Starch +O2
Correct Answer
B. Ethyle Alcohol +CO2Explanation
Yeast is a microorganism that undergoes a process called fermentation. During fermentation, yeast converts simple sugars into ethanol (ethyl alcohol) and carbon dioxide. This process is commonly used in the production of alcoholic beverages and bread-making. Therefore, the correct answer is "Ethyl Alcohol + CO2."Rate this question:
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- 26.
Which orbital has lowest energy?
- A.
3d
- B.
4s
- C.
3p
- D.
4f
- E.
5f
Correct Answer
C. 3pExplanation
The 3p orbital has the lowest energy among the given options. This is because the energy levels of orbitals increase as the principal quantum number (n) increases. In this case, the 3p orbital has a lower principal quantum number (n=3) compared to the 4s, 4f, and 5f orbitals, which have higher values of n. The 3d orbital also has a higher energy level than the 3p orbital, as the d orbitals have higher energy than the p orbitals within the same principal quantum number.Rate this question:
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- 27.
Positively charged Oxygen when bonded with three different atoms or Groups of atom is called?
- A.
Oxygen ion
- B.
Oxime
- C.
Oxinium ion
- D.
Oxide ion
- E.
Hydroxide ion
Correct Answer
C. Oxinium ionExplanation
When oxygen is bonded with three different atoms or groups of atoms, it forms a positively charged ion called oxinium ion. This ion is formed when oxygen gains three electrons, resulting in a positive charge. The other options listed are not correct because they either refer to different types of ions or compounds formed by oxygen.Rate this question:
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- 28.
Polyvinyle chloride is an industrial prepared from?
- A.
Ethene
- B.
Ethyne
- C.
Ethane
- D.
Chlorine
- E.
None of above
Correct Answer
B. EthyneExplanation
Polyvinyl chloride (PVC) is an industrial polymer that is prepared from ethyne. Ethyne, also known as acetylene, is a hydrocarbon compound that is used as a starting material in the production of PVC. By reacting ethyne with chlorine, PVC is formed through a chemical process called polymerization. Ethene, ethane, and chlorine are not directly involved in the synthesis of PVC.Rate this question:
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- 29.
The colour of Transition metal complexes is associated with
- A.
Losing Electron
- B.
Gaining electron
- C.
D-d transition of electron
- D.
Unpaired electron
- E.
Paired electron
Correct Answer
C. D-d transition of electronExplanation
The color of transition metal complexes is associated with d-d transition of electrons. Transition metals have partially filled d orbitals, and when light interacts with these electrons, it causes them to absorb specific wavelengths of light. The absorbed light energy promotes the electrons to higher energy levels, resulting in the observed color. The energy difference between the d orbitals determines the color of the complex. Therefore, the d-d transition of electrons is responsible for the color exhibited by transition metal complexes.Rate this question:
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- 30.
Stainless steel is the
- A.
Magnisium based Alloy
- B.
Iron based alloy
- C.
Chromium based alloy
- D.
Alluminium based alloy
Correct Answer
B. Iron based alloyExplanation
Stainless steel is an iron-based alloy because it primarily consists of iron as the base metal. It also contains a significant amount of chromium, which provides its corrosion-resistant properties. Other elements like nickel, manganese, and carbon are added to enhance specific characteristics such as strength, ductility, and resistance to heat. The iron base gives stainless steel its structural integrity and strength, making it a widely used material in various industries including construction, automotive, and manufacturing.Rate this question:
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- 31.
Graph Between volume and Tempreture at Constant pressure is
- A.
Stright line
- B.
Curved
- C.
Parabolic
- D.
None of these
Correct Answer
A. Stright lineExplanation
The graph between volume and temperature at constant pressure is a straight line because according to Charles's Law, the volume of a gas is directly proportional to its temperature when the pressure is held constant. As the temperature increases, the volume of the gas also increases in a linear manner. This relationship is represented by a straight line on the graph.Rate this question:
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- 32.
: L,M and N are ideal gases .The molecular weights t 44,16, and 32 respectively the rate of diffusion of these Gases follows order
- A.
L>M>N
- B.
L>N>M
- C.
M=N=L
- D.
M>N>L
Correct Answer
D. M>N>LExplanation
The rate of diffusion of gases is inversely proportional to their molecular weights. Since M has the lowest molecular weight, it will have the highest rate of diffusion. N has a higher molecular weight than M, so it will have a slower rate of diffusion. L has the highest molecular weight among the three gases, so it will have the slowest rate of diffusion. Therefore, the correct order of the rate of diffusion is M>N>L.Rate this question:
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- 33.
Which of the Following Hydrocarbans lowest Melting point
- A.
Ethane
- B.
Propane
- C.
Butane
- D.
Pentane
- E.
Hexane
Correct Answer
A. EthaneExplanation
The melting point of a hydrocarbon is determined by its molecular structure and intermolecular forces. Ethane, with the formula C2H6, has the lowest melting point among the given options. This is because ethane consists of only two carbon atoms and six hydrogen atoms, resulting in weaker intermolecular forces compared to the other hydrocarbons. Propane, butane, pentane, and hexane have larger and more complex molecular structures, leading to stronger intermolecular forces and higher melting points.Rate this question:
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- 34.
The contact process for preparation of H2SO4 the catalyst is used is
- A.
Fe
- B.
Sun light
- C.
V2O5
- D.
NO+NO2
- E.
Nickle
Correct Answer
C. V2O5Explanation
V2O5 is the catalyst used in the contact process for the preparation of H2SO4. The contact process involves the oxidation of sulfur dioxide to sulfur trioxide, which is then converted to sulfuric acid. V2O5 acts as a catalyst in this process, facilitating the reaction by lowering the activation energy required for the conversion of sulfur dioxide to sulfur trioxide.Rate this question:
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- 35.
H2+I2------>2HI This reaction independent of
- A.
Temperature
- B.
Concentration
- C.
Pressure
- D.
Reactants
- E.
Catalyst
Correct Answer
C. PressureExplanation
The given reaction, H2+I2->2HI, does not depend on pressure. Pressure is the force exerted by a gas on its surroundings and does not affect the formation of the products in this reaction. The reaction can proceed at any pressure, as long as the reactants are present. The rate of the reaction may be affected by pressure, but the overall outcome of the reaction remains the same.Rate this question:
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- 36.
The Molecular Orbital picture of O2 indicates the
- A.
One unpaired Electron
- B.
Two unpaired Electrons
- C.
Three unpaired electron
- D.
One paired Electron
- E.
None of above
Correct Answer
B. Two unpaired ElectronsExplanation
The molecular orbital picture of O2 indicates two unpaired electrons. In molecular orbital theory, electrons are distributed in molecular orbitals formed by the overlap of atomic orbitals. In the case of O2, the molecular orbital diagram shows that there are two unpaired electrons in the antibonding pi* orbitals. This means that O2 has two unpaired electrons available for bonding, making it a paramagnetic molecule.Rate this question:
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- 37.
With the increase of size down the Group the ionization enthalpies
- A.
Increase
- B.
Decrease
- C.
First increase then decrease
- D.
First Decrease and Then decrease
Correct Answer
B. DecreaseExplanation
As we move down a group in the periodic table, the size of the atoms increases due to the addition of new energy levels. This increase in size leads to a decrease in the effective nuclear charge experienced by the outermost electrons. As a result, these electrons are less strongly attracted to the nucleus and are easier to remove, leading to a decrease in ionization enthalpies. Therefore, the correct answer is "decrease".Rate this question:
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- 38.
The property of being able to add enthalpies is based on the
- A.
Law of conservation of Heat
- B.
Law of activation of mass
- C.
First law of Thermodynamics
- D.
Law of E =mc2
- E.
Hess's Law
Correct Answer
E. Hess's LawExplanation
Hess's Law states that the total enthalpy change of a reaction is independent of the pathway taken. This means that the enthalpy change of a reaction can be calculated by considering the enthalpy changes of the individual steps involved, regardless of the intermediate reactions or the method used to achieve the final reaction. In other words, the enthalpy change is additive and can be determined by summing the enthalpy changes of the individual steps. This property allows for the addition of enthalpies, making Hess's Law a fundamental principle in thermochemistry.Rate this question:
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- 39.
All are electrophlic reaction Of Benzene Except
- A.
Nitration
- B.
Halogenation
- C.
Sulphonation
- D.
Alkylation and acylation
- E.
Conjugation
Correct Answer
E. ConjugationExplanation
Conjugation is not an electrophilic reaction of benzene. Electrophilic reactions involve the attack of an electrophile on the electron-rich benzene ring. Nitration, halogenation, sulphonation, alkylation, and acylation are all examples of electrophilic reactions where an electrophile reacts with the benzene ring. However, conjugation refers to the delocalization of electrons in a molecule, which can occur in benzene due to its alternating double bonds. It is not a reaction in itself, but rather a property of the molecule.Rate this question:
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- 40.
Night blindness is caused by deficiency of ....... Vitamin?
- A.
Vitamin A
- B.
Vitamin B
- C.
Vitamin C
- D.
Vitamin E
- E.
Vitamin D
Correct Answer
A. Vitamin AExplanation
Night blindness is caused by a deficiency of Vitamin A. Vitamin A is essential for the proper functioning of the retina, which is responsible for vision in low light conditions. A lack of Vitamin A can lead to a condition called night blindness, where individuals have difficulty seeing in dim light or at night. Consuming foods rich in Vitamin A, such as carrots, spinach, and sweet potatoes, can help prevent night blindness and maintain good vision.Rate this question:
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- 41.
Ammonia is prepared by ______ method
- A.
Nelson cell
- B.
Hyber process
- C.
Downs cell
- D.
Contact process
- E.
Solutions process
Correct Answer
B. Hyber processExplanation
The correct answer is "Hyber process". However, there is no information provided in the question about the different methods of preparing ammonia. Therefore, it is not possible to provide a specific explanation for why the Hyber process is the correct answer.Rate this question:
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- 42.
Oxidation of Secondary Alcohol product Gives
- A.
Aldehyde
- B.
Ketone
- C.
Carboxylic acid
- D.
Phenol
- E.
Esters
Correct Answer
B. KetoneExplanation
The oxidation of a secondary alcohol results in the formation of a ketone. This is because secondary alcohols have two alkyl groups attached to the carbon atom bearing the hydroxyl group. During oxidation, the hydrogen atom attached to the carbon atom is removed, and the resulting carbonyl group forms a double bond with the carbon atom. This leads to the formation of a ketone, which contains a carbonyl group bonded to two alkyl or aryl groups.Rate this question:
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- 43.
Which of the following Covalent Hydride?
- A.
NaBH4
- B.
ZnH2
- C.
NaH
- D.
CaH2
- E.
H2S
Correct Answer
E. H2SExplanation
H2S is the correct answer because it is a covalent hydride. Covalent hydrides are compounds in which hydrogen is bonded to a nonmetallic element through a covalent bond. In H2S, hydrogen is bonded to sulfur through a covalent bond, making it a covalent hydride. The other options, NaBH4, ZnH2, NaH, and CaH2, are not covalent hydrides as they involve hydrogen bonding with metallic elements or ionic bonding.Rate this question:
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- 44.
Rate determining step of SN1 reaction is always
- A.
Slow step
- B.
Fast step
- C.
Intermediate step
- D.
Second step
- E.
None of above
Correct Answer
A. Slow stepExplanation
The rate-determining step of an SN1 reaction is always the slow step. In an SN1 reaction, the leaving group first dissociates from the substrate, forming a carbocation intermediate. This step is relatively slow because it involves the breaking of a bond. The subsequent step, which involves the nucleophile attacking the carbocation, is fast in comparison. Therefore, the slow step, where the carbocation is formed, determines the overall rate of the reaction.Rate this question:
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- 45.
The stable Electronic Configuration of Cu=29
- A.
[Ar]4s1 ,3d10
- B.
[Ar]4s2,3d9
- C.
[Ar]4s0,3d10
- D.
[Ar]4s2,3d8
Correct Answer
A. [Ar]4s1 ,3d10Explanation
The stable electronic configuration of Cu is [Ar]4s1, 3d10. This means that the Cu atom has a total of 29 electrons. The [Ar] represents the electron configuration of the noble gas argon, which has 18 electrons. The 4s1 indicates that there is one electron in the 4s orbital, and the 3d10 indicates that there are 10 electrons in the 3d orbital. This configuration is stable because it follows the Aufbau principle, which states that electrons fill orbitals in order of increasing energy.Rate this question:
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- 46.
Calciferol is also known as
- A.
Vitamin A
- B.
Vitamin B
- C.
Vitamin C
- D.
Vitamin D
- E.
Vitamin E
Correct Answer
D. Vitamin DExplanation
Calciferol is another name for Vitamin D. Vitamin D is a fat-soluble vitamin that helps in the absorption of calcium and phosphorus in the body. It is essential for maintaining strong bones and teeth, as well as promoting proper immune function and cell growth. Vitamin D can be obtained through exposure to sunlight, as well as through certain foods and supplements.Rate this question:
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- 47.
EDTA is
- A.
Polydentate
- B.
Hexodentate
- C.
Chelating agents
- D.
All of these
Correct Answer
B. HexodentateExplanation
Hexodentate refers to a molecule or ion that can form six coordinate bonds with a metal ion. EDTA (Ethylene diamine tetraacetic acid) is a hexodentate ligand, meaning it has six donor atoms that can bind to a metal ion. This property allows EDTA to form stable complexes with metal ions, making it a widely used chelating agent in various applications, such as in medicine and analytical chemistry. Therefore, the correct answer is Hexodentate.Rate this question:
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- 48.
250 cm3 of the simple of hydrogen effuses four times as rapidly as 250 cm3 of an unknown gas. Calculate the molar mass of unknown gas.?
- A.
45g/mol
- B.
40g/mol
- C.
32g/mol
- D.
41g/mol
- E.
38g/mol
Correct Answer
C. 32g/mol -
- 49.
Ruby is a crystal of:
- A.
Al2O3
- B.
PbO3
- C.
KO2
- D.
SO4
- E.
None
Correct Answer
A. Al2O3Explanation
Ruby is a crystal of Al2O3, which is also known as aluminum oxide. Ruby is a red gemstone and is a variety of the mineral corundum. Corundum is composed of aluminum and oxygen, with the chemical formula Al2O3. Ruby gets its red color from trace amounts of the element chromium. It is a precious gemstone and is highly valued for its beauty and rarity.Rate this question:
-
- 50.
Mostly hydrogen are formed in laboratory from which Hydride?
- A.
CaH2
- B.
MgH2
- C.
NaH
- D.
ZnH2
Correct Answer
A. CaH2Explanation
CaH2 is the correct answer because it is calcium hydride. Calcium hydride is commonly used in laboratories to generate hydrogen gas. When CaH2 reacts with water, it produces hydrogen gas and calcium hydroxide. This reaction is often used as a convenient method for generating hydrogen gas in the laboratory. Therefore, CaH2 is the most likely hydride to be used for the formation of hydrogen in a laboratory setting.Rate this question:
-
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Current Version
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Mar 21, 2023Quiz Edited by
ProProfs Editorial Team -
Aug 23, 2019Quiz Created by
Jan Samad
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