10+ L&T Construction Interview Questions and Answers

Solution, solvent, and solute are terms used in chemistry to describe the components of a homogeneous mixture.

• A solution is a homogeneous mixture composed of a solvent and one or more solutes.

• The solvent is the substance that dissolves the solute(s) to form the solution.

• The solute is the substance that is dissolved in the solvent to form the solution.

• For example, in a saltwater solution, water is the solvent and salt is the solute.

pH is a measure of acidity or alkalinity of a solution on a scale of 0-14.

• pH stands for 'potential of hydrogen'

• A pH of 7 is neutral, below 7 is acidic, and above 7 is alkaline

• The pH scale is logarithmic, meaning each whole number change represents a tenfold change in acidity or alkalinity

• Examples of pH values: lemon juice (2.0), vinegar (2.5), water (7.0), baking soda (8.5), ammonia (11.5)

Strong acids and bases dissociate completely in water, while weak acids and bases only partially dissociate.

• Strong acids: HCl, HNO3, H2SO4

• Strong bases: NaOH, KOH, Ca(OH)2

• Weak acids: acetic acid, carbonic acid

• Weak bases: ammonia, pyridine

Raman spectroscopy is a technique used to study vibrational, rotational, and other low-frequency modes in a system.

• It involves the use of a laser to excite the molecules in a sample, causing them to vibrate and emit light at different wavelengths.

• The resulting spectrum can be used to identify the chemical composition of the sample and study its molecular structure.

• Raman spectroscopy is commonly used in materials science, chemistry, and biology.

• It can be used to analyze the co...read more

Acid and base are two types of chemical substances with opposite properties.

• Acids are substances that donate hydrogen ions (H+) in a solution.

• Bases are substances that accept hydrogen ions (H+) in a solution.

• Acids have a pH value less than 7, while bases have a pH value greater than 7.

• The reaction between an acid and a base is called neutralization, which results in the formation of salt and water.

• Examples of acids include hydrochloric acid, sulfuric acid, and citric acid, wh...read more

End point refers to the point at which a process or reaction is considered complete.

• It is the final stage of a process or reaction

• It is the point at which a desired outcome is achieved

• In quality control, it is the point at which a product meets the required specifications

• Examples include the endpoint of a titration, the endpoint of a chemical reaction, and the endpoint of a manufacturing process

Spectroscopy is the study of the interaction between matter and electromagnetic radiation.

• It involves the measurement of the absorption, emission, or scattering of electromagnetic radiation by a sample.

• It is used in various fields such as chemistry, physics, astronomy, and biology.

• Examples include UV-Vis spectroscopy, infrared spectroscopy, and nuclear magnetic resonance spectroscopy.

• It can be used for qualitative and quantitative analysis of samples.

• It can provide informatio...read more

Normality refers to the concentration of a solution in terms of the number of equivalents of solute per liter of solution.

• Normality is a measure of concentration used in chemistry.

• It is defined as the number of equivalents of solute per liter of solution.

• It is different from molarity, which is the number of moles of solute per liter of solution.

• For example, a 1N solution of hydrochloric acid contains 1 equivalent of HCl per liter of solution.

• Normality is often used in acid-ba...read more

Molarity is a measure of the concentration of a solution expressed as the number of moles of solute per liter of solution.

• Molarity is calculated by dividing the number of moles of solute by the volume of the solution in liters.

• It is denoted by the symbol 'M'.

• Molarity is commonly used in chemistry to express the concentration of a solution.

• For example, a 1 M solution of sodium chloride contains 1 mole of sodium chloride per liter of solution.

HPLC is a technique used in quality control to separate, identify, and quantify components in a mixture.

• HPLC stands for High-Performance Liquid Chromatography.

• It is based on the principle of separating components of a mixture using a liquid mobile phase and a solid stationary phase.

• The separation is achieved by the differential interaction of the components with the stationary phase.

• The components are detected and quantified using a detector, such as UV-Vis spectroscopy or ma...read more

UV principle is based on the absorption of light by molecules and atoms, leading to electronic transitions.

• UV radiation causes electronic transitions in molecules and atoms

• The energy absorbed by the molecule or atom is proportional to the wavelength of the UV radiation

• UV spectroscopy is used to identify functional groups in organic molecules

• UV radiation is also used for sterilization and disinfection purposes