1.
What is the term given to the difference between observed value and true value during analysis?
Correct Answer
B. Error
Explanation
The term given to the difference between observed value and true value during analysis is called "error". Error represents the deviation or discrepancy between the actual value and the value that is expected or desired. It is a measure of how accurate or precise the analysis or measurement is.
2.
Which of these is important if rusting must occur?
Correct Answer
A. Water and oxygen
Explanation
Rusting is a chemical process that occurs when iron or steel is exposed to water and oxygen. In the presence of water, iron reacts with oxygen in the air to form iron oxide, commonly known as rust. Therefore, water and oxygen are essential for the rusting process to occur. Nitrogen and carbon do not play a direct role in rusting, so they are not important in this context.
3.
What is the source compound in polymerisation called?
Correct Answer
D. Monomer
Explanation
In polymerization, the source compound is called a monomer. A monomer is a small molecule that can join together with other monomers to form a larger polymer chain. It acts as the building block for the polymerization process, where the monomers undergo a chemical reaction to form the polymer. The monomer provides the necessary chemical structure and functionality for the polymerization reaction to occur, leading to the formation of a polymer with specific properties and characteristics.
4.
Which of these is involved in an organic reaction?
Correct Answer
B. Organic compounds
Explanation
Organic reactions involve the participation of organic compounds. Organic compounds are compounds that contain carbon atoms bonded to hydrogen atoms, as well as other elements such as oxygen, nitrogen, and sulfur. These compounds are known for their ability to undergo chemical reactions, such as addition, substitution, and elimination reactions. Carbon is a key component of organic compounds and is essential for the formation of the unique structures and properties exhibited by organic compounds. Zinc and inorganic compounds, on the other hand, are not typically involved in organic reactions.
5.
How many electrodes are in an electrochemical cell?
Correct Answer
D. 2
Explanation
An electrochemical cell typically consists of two electrodes, an anode and a cathode. These electrodes are used to facilitate the transfer of electrons between the reactants in the cell. Therefore, the correct answer is 2.
6.
Which of these involves the addition of a reactant to a solution being analyzed until some equivalent point is reached?
Correct Answer
B. Titration
Explanation
Titration involves the gradual addition of a reactant to a solution being analyzed until the equivalent point is reached. This process is used to determine the concentration of an unknown substance in a sample by reacting it with a known substance of known concentration. The equivalent point is reached when the stoichiometric ratio between the reactants has been achieved, indicating that the reaction is complete. Therefore, titration is the correct answer as it specifically involves the addition of a reactant until the equivalent point is reached.
7.
Which of these qualitative chemical test is used to test for the presence of blood?
Correct Answer
D. Kastle-Meyer Test
Explanation
The Kastle-Meyer Test is used to test for the presence of blood. This test involves adding a reagent solution to a sample, which causes a color change if blood is present. The reagent contains hydrogen peroxide and phenolphthalein, and when it comes into contact with blood, it causes a pink color to appear. This test is commonly used in forensic science to detect the presence of blood at crime scenes.
8.
In the transfer of electron, the donor is known to have undergone which of the following processes?
Correct Answer
A. Reduction
Explanation
Reduction is the process in which a substance gains electrons. In the transfer of electrons, the donor is the one that loses electrons and gets oxidized. Therefore, the correct answer is reduction because the donor is undergoing a reduction process by losing electrons.
9.
What is the term given to the study of reaction rate?
Correct Answer
D. Chemical kinetics
Explanation
Chemical kinetics is the term given to the study of reaction rate. It involves the investigation of how fast chemical reactions occur and the factors that influence their rate. This field of study helps scientists understand the mechanisms behind reactions, predict reaction rates, and optimize reaction conditions. Stochiometric refers to the study of the quantitative relationships between reactants and products in a chemical reaction, while kinematics is the study of motion. Chemical reaction is a broad term that encompasses all types of reactions, not just the study of their rates.
10.
What type of change is the melting of ice?
Correct Answer
B. pHysical
Explanation
The melting of ice is a physical change. This is because during the process of melting, the ice changes from a solid state to a liquid state without any change in its chemical composition. The molecules in the ice gain enough energy to break their rigid structure and become more fluid, resulting in the formation of water. Therefore, the change is purely physical as there is no alteration in the chemical makeup of the substance.