B.Sc.First Year Online Practical Examination In Chemistry
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Below reaction is used in confirmation of -------- element during element detection process.
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Nitrogen
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Sulhur
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Halogen
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None of these
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About This Quiz
This B. Sc. First Year Online Practical Examination in Chemistry assesses knowledge in organic functional groups, Lassaigne's test, and properties of chemical compounds. It's designed to evaluate practical understanding and application skills in chemistry.
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- 2.
The element which cannot be detected through Lassaigne’s test is
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Sulphur
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Oxygen
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Nitrogen
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Chlorine
Correct Answer
A. OxygenExplanation
Lassaigne's test is a chemical test used to detect the presence of elements like nitrogen, sulphur, and halogens (such as chlorine) in an organic compound. However, oxygen cannot be detected through Lassaigne's test because it does not form any characteristic compound that can be detected using this test. Therefore, the correct answer is Oxygen.Rate this question:
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- 3.
Above Apparatus used for determination of
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Surface tension
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Melting point
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Freezing point
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Viscosity
Correct Answer
A. Melting pointExplanation
The above apparatus is used for the determination of the melting point. This can be inferred from the options given, where the other three options (surface tension, freezing point, and viscosity) are unrelated to the apparatus shown. The apparatus appears to be a melting point apparatus, typically used in laboratories to determine the temperature at which a substance changes from a solid to a liquid state.Rate this question:
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- 4.
The element which cannot be detected through Lassaigne’s test is
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Sulphur
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Oxygen
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Nitrogen
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Chlorine
Correct Answer
A. OxygenExplanation
Lassaigne's test is used to detect the presence of elements like nitrogen, sulphur, and chlorine in an organic compound. However, oxygen cannot be detected through Lassaigne's test as it does not form any specific compound that can be identified using this test. Therefore, the correct answer is Oxygen.Rate this question:
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- 5.
The element which cannot be detected through Lassaigne’s test is
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Sulphur
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Oxygen
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Nitrogen
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Chlorine
Correct Answer
A. OxygenExplanation
Lassaigne's test is a chemical test used to detect the presence of elements such as sulphur, nitrogen, and chlorine in organic compounds. However, oxygen cannot be detected through this test because it is already present in most organic compounds and is not easily separated or detected using Lassaigne's test. Therefore, the correct answer is oxygen.Rate this question:
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- 6.
Following reaction take place during preparation of Lassaigne extract.
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True
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False
Correct Answer
A. TrueExplanation
The given statement "Following reaction take place during preparation of Lassaigne extract" is true. Lassaigne extract is a solution used in organic chemistry to detect the presence of nitrogen, sulfur, and halogens in a compound. During the preparation of Lassaigne extract, reactions occur between the compound being tested and sodium metal, resulting in the formation of sodium compounds of nitrogen, sulfur, and halogens. These compounds are then extracted into water and can be further analyzed. Therefore, the statement is true.Rate this question:
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- 7.
The ionic compound formed during the fusion of 1,2-Dichloro benzene with sodium metal is AgCN
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True
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False
Correct Answer
A. FalseExplanation
The given statement is false. The fusion of 1,2-Dichloro benzene with sodium metal does not result in the formation of AgCN (Silver Cyanide). The correct answer is not provided, but it can be determined that the given statement is false based on the information given.Rate this question:
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- 8.
The existence of strong intermolecular forces of attraction in liquids gives rise to important property known as--
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Boiling point
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Surface tension
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Viscosity
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Optical activity
Correct Answer
A. Surface tensionExplanation
The existence of strong intermolecular forces of attraction in liquids gives rise to surface tension. Surface tension is the property of the surface of a liquid that allows it to resist external forces and minimize its surface area. This is due to the cohesive forces between the molecules at the surface, which pull the molecules inward and create a "skin" or "film" on the surface. Surface tension is responsible for phenomena such as capillary action, droplet formation, and the ability of insects to walk on water.Rate this question:
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- 9.
SI unit of suface tension
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Nm-1
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Dynes cm-1
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Both
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None of these
Correct Answer
A. Nm-1Explanation
The SI unit of surface tension is Nm-1. Surface tension is defined as the force acting per unit length on the surface of a liquid. The unit Nm-1 represents the force in Newtons acting on a surface of 1 meter in length. This unit is commonly used to measure surface tension in scientific and engineering applications.Rate this question:
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- 10.
compound parachor value Ethane 110.5 propane 150.8 Butane 190 from the data given above Parachor value of CH2 group is -----------
Correct Answer
40.3Explanation
The given data provides the Parachor values for three different compounds: ethane, propane, and butane. By comparing these values, it can be observed that as the number of carbon atoms in the compound increases, the Parachor value also increases. This indicates that the Parachor value is directly proportional to the size of the compound. Since the CH2 group is present in all three compounds, it can be inferred that the Parachor value of the CH2 group is 40.3.Rate this question:
- 11.
What will be the colour of final compound formed in given reaction
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Orange-red
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Orange
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Blue
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Colourless
Correct Answer
A. Orange-redExplanation
The final compound formed in the given reaction is orange-red.Rate this question:
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- 12.
The Force of friction between two layers of a liquid moving past one another with different velocities is
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Surface tension
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Viscosity
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Density
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Refractive index
Correct Answer
A. ViscosityExplanation
Viscosity is the correct answer because it refers to the internal friction or resistance to flow in a fluid. When two layers of a liquid are moving past one another with different velocities, the viscosity of the liquid determines the force of friction between the layers. A higher viscosity means a higher force of friction, while a lower viscosity means a lower force of friction. Surface tension, density, and refractive index do not directly relate to the force of friction between layers of a liquid moving past one another.Rate this question:
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- 13.
What is the effect of temperature on Viscosity?
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Decreases
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Increases
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Remain constant
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Can not be predicted
Correct Answer
A. DecreasesExplanation
The effect of temperature on viscosity is that it decreases. As temperature increases, the kinetic energy of the molecules in a substance also increases. This increased kinetic energy causes the molecules to move more freely, reducing the friction between them and lowering the viscosity. Conversely, as temperature decreases, the molecules move more slowly and the friction between them increases, resulting in higher viscosity. Therefore, the viscosity of a substance is inversely proportional to temperature.Rate this question:
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- 14.
Which of the following express the Unit of Viscosity
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Dyne second Cm-1
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Centipoise
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Kg m-1 S-1
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All of the above
Correct Answer
A. All of the aboveExplanation
All of the options listed, namely dyne second Cm-1, centipoise, and Kg m-1 S-1, express the unit of viscosity. Viscosity is a measure of a fluid's resistance to flow, and it is typically measured in different units depending on the system being used. Dyne second Cm-1 is the unit used in the CGS (centimeter-gram-second) system, centipoise is a commonly used unit in the metric system, and Kg m-1 S-1 is the unit used in the SI (International System of Units) system. Therefore, all of the options provided correctly express the unit of viscosity.Rate this question:
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- 15.
Functional group present in Aniline is
Correct Answer
Amine, -NH2, Amino,amine group, primary amineExplanation
Aniline contains an amine functional group, specifically a primary amine group (-NH2). A primary amine is characterized by the presence of a nitrogen atom bonded to two hydrogen atoms and one carbon atom. In the case of aniline, the nitrogen atom is part of an aromatic ring, making it an aromatic primary amine. The presence of this functional group is responsible for the basic properties and reactivity of aniline.Rate this question:
- 16.
Fuctional group present in above structure are
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Carboxylic Acid
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Phenolic OH
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Carbonyl Group
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Ketone
Correct Answer(s)
A. Carboxylic Acid
A. Phenolic OH
A. Carbonyl GroupExplanation
The given structure contains a carboxylic acid functional group, which is characterized by the presence of a carboxyl group (-COOH). This group consists of a carbonyl group (C=O) and a hydroxyl group (OH) attached to the same carbon atom. Additionally, the structure also contains a phenolic OH group, which is a hydroxyl group attached to a benzene ring. Lastly, there is a carbonyl group present in the structure, which is a carbon atom double bonded to an oxygen atom (C=O). Therefore, the functional groups present in the structure are carboxylic acid, phenolic OH, and carbonyl group.Rate this question:
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Mar 21, 2023Quiz Edited by
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May 21, 2020Quiz Created by
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