100+ Chemist Interview Questions and Answers

pH is a measure of acidity or basicity of a solution. Normality, molarity, and molality are units of concentration.

• pH is measured on a scale of 0-14, with 7 being neutral, below 7 acidic, and above 7 basic.

• Normality is the number of equivalents of a solute per liter of solution.

• Molarity is the number of moles of a solute per liter of solution.

• Molality is the number of moles of a solute per kilogram of solvent.

• Other basic concepts include titration, buffer solutions, and acid-...read more

Organic chemistry is the study of carbon-based compounds. pH measures acidity or alkalinity. TLC is a technique for separating compounds.

• Organic chemistry focuses on the study of carbon-containing compounds.

• pH is a measure of the acidity or alkalinity of a solution.

• TLC (Thin Layer Chromatography) is a technique used to separate and analyze compounds in a mixture.

• Polar solvents dissolve polar compounds, while non-polar solvents dissolve non-polar compounds.

• 1N HCl (1 Normal hyd...read more

pH is a measure of acidity or alkalinity. Drinking water pH should be around 7. Spectrophotometer measures light absorption. No medical field.

• pH is a measure of the concentration of hydrogen ions in a solution

• Drinking water pH should be around 7, which is considered neutral

• Spectrophotometer operates based on the principle of measuring the absorption of light by a sample

• In my education, I have tested various chemical reactions and performed titrations

• I have operated instrument...read more

Normality, molality, and molarity are different ways to express the concentration of a solution.

• Normality is the concentration of a solution expressed in equivalents per liter.

• Molality is the concentration of a solution expressed in moles of solute per kilogram of solvent.

• Molarity is the concentration of a solution expressed in moles of solute per liter of solution.

• Normality is used in acid-base reactions, while molality and molarity are used in general chemistry.

• For example,...read more

To prepare chlorobenzene, benzene is treated with chlorine in the presence of a catalyst. Phenol is acidic and polar. Bulk density is the mass of a unit volume of a substance.

• Chlorobenzene is prepared by treating benzene with chlorine in the presence of a catalyst

• Known solvents for chlorobenzene include ethanol, diethyl ether, and carbon tetrachloride

• Phenol is acidic due to the presence of a hydroxyl group, and it is polar due to the electronegativity difference between oxyge...read more

The density of H2SO4 and HNO3 varies depending on the concentration.

• The density of H2SO4 and HNO3 can be calculated using the formula: density = mass/volume.

• The density of H2SO4 and HNO3 increases with increasing concentration.

• The density of H2SO4 and HNO3 at standard conditions (concentration of 1 M) is approximately 1.84 g/mL and 1.41 g/mL, respectively.

The interview questions are related to cement testing procedures, grades, flyash, admixture, aggregates, water, and design mix.

• Cement testing procedures are done to ensure the quality of cement as per IS code.

• IS code for grade of cement specifies the compressive strength of cement at 28 days.

• Flyash is a byproduct of coal combustion and can be used as a partial replacement of cement.

• Admixtures are added to improve the workability, strength, and durability of concrete.

• Coarse an...read more

pH indicators, name reactions, and acid-base differentiation are important topics in chemistry.

• pH indicators are substances that change color depending on the pH of the solution they are in, such as litmus paper or phenolphthalein.

• Name reactions are specific chemical reactions that have been named after their discoverers or developers, such as the Grignard reaction or the Friedel-Crafts reaction.

• Acid-base differentiation is the process of identifying whether a substance is an...read more

The molecular weight of H2SO4 is 98.09 g/mol.

• The molecular weight of H2SO4 can be calculated by adding up the atomic weights of its constituent elements.

• H2SO4 consists of 2 hydrogen atoms, 1 sulfur atom, and 4 oxygen atoms.

• The atomic weights of hydrogen, sulfur, and oxygen are 1.008 g/mol, 32.06 g/mol, and 16.00 g/mol respectively.

• Multiplying the atomic weights by the number of atoms and summing them gives the molecular weight of H2SO4 as 98.09 g/mol.

Acids and bases are substances that can donate or accept protons, respectively.

• Acids are substances that release hydrogen ions (H+) in water.

• Bases are substances that release hydroxide ions (OH-) in water.

• Acids and bases can also be defined based on their chemical properties, such as their ability to neutralize each other.

• Examples of acids include hydrochloric acid (HCl) and sulfuric acid (H2SO4).

• Examples of bases include sodium hydroxide (NaOH) and ammonia (NH3).

There are various types of distillation techniques used in chemistry, such as simple distillation, fractional distillation, and steam distillation.

• Simple distillation is used to separate liquids with different boiling points.

• Fractional distillation is used to separate liquids with similar boiling points.

• Steam distillation is used to extract volatile compounds from plants or organic materials.

• Other types of distillation include vacuum distillation, azeotropic distillation, and...read more

The UV-visible region ranges from 200-800 nm while the UV region ranges from 10-200 nm.

• UV-visible region is the range of electromagnetic radiation that is visible to the human eye and includes wavelengths from 200-800 nm.

• The UV region is the range of electromagnetic radiation with shorter wavelengths than visible light and includes wavelengths from 10-200 nm.

• UV radiation is commonly used in analytical chemistry for spectroscopic analysis.

• UV radiation is also responsible for c...read more

Total alkalinity, total hardness, and fluoride tests are important for determining the quality of drinking water as per BIS standards.

• Total alkalinity can be determined by titration with acid and phenolphthalein indicator.

• Total hardness can be determined by titration with EDTA and a metal indicator.

• Fluoride test can be done using a fluoride ion-selective electrode.

• BIS standards for drinking water include parameters such as pH, total dissolved solids, and microbiological conta...read more

Answering questions related to titration, molarity, normality, and organic chemistry.

• Titration is a technique used to determine the concentration of a solution.

• Types of titration include acid-base, redox, complexometric, and precipitation titration.

• Molarity is the number of moles of solute per liter of solution.

• Normality is the number of equivalents of solute per liter of solution.

• Organic chemistry is the study of carbon-based compounds.

• The four types of titration are acid-ba...read more

Testing is a process of evaluating the performance or characteristics of a substance or system.

• Testing involves conducting experiments or analyses to gather data and draw conclusions.

• It is used to ensure the quality, safety, and effectiveness of products or processes.

• Chemical testing may involve analyzing the composition, purity, or properties of substances.

• Testing methods can include physical, chemical, or biological techniques.

• Examples of testing in chemistry include titrat...read more

HPLC stands for High-Performance Liquid Chromatography, a technique used to separate, identify, and quantify components in a mixture.

• HPLC is a widely used analytical technique in chemistry and biochemistry.

• It involves the use of a liquid mobile phase and a stationary phase to separate and analyze components in a sample.

• The separation is based on the differential interaction of the sample components with the stationary phase.

• HPLC can be used to analyze a wide range of compound...read more

As a chemist, I can contribute to your organization by conducting research, developing new products, and ensuring quality control.

• Conducting research to discover new compounds or improve existing ones

• Developing new products or improving existing ones

• Ensuring quality control by testing and analyzing samples

• Collaborating with other scientists and departments to solve problems

• Keeping up-to-date with the latest advancements in the field

LOD stands for Limit of Detection. It is the lowest concentration of a substance that can be reliably detected.

• LOD is used to determine the sensitivity of an analytical method.

• It is usually expressed as a concentration or mass.

• Water is a chemical compound composed of hydrogen and oxygen, while LOD is a term used in analytical chemistry.

• LOD is important in environmental testing to determine the presence of contaminants in water.

• LOD can be affected by various factors such as in...read more

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

• Molarity = moles of solute / liters of solution

• Glucose formula: C6H12O6

• Molar mass of glucose: 180.156 g/mol

• If we dissolve 1 mole of glucose in 1 liter of solution, the molarity will be 1 M

• To calculate the molarity of glucose, we need to know the mass of glucose and the volume of the solution

I operate the fractional distillation column.

• I have experience operating a fractional distillation column.

• I am familiar with the principles and techniques of fractional distillation.

• I have successfully used a fractional distillation column to separate mixtures of liquids based on their boiling points.

• I can provide examples of specific mixtures I have separated using a fractional distillation column.

AA is a common abbreviation for amino acids. They have a general structure of NH2-CHR-COOH and can undergo various named reactions like Grignard reaction.

• AA stands for amino acids which are the building blocks of proteins

• Their general structure is NH2-CHR-COOH where R can be any of the 20 different side chains

• Grignard reaction is a named reaction used to form carbon-carbon bonds and is commonly used in organic synthesis

Boiling point is the temperature at which a liquid turns into a gas, while melting point is the temperature at which a solid turns into a liquid.

• Boiling point is dependent on atmospheric pressure.

• Melting point is dependent on the substance's intermolecular forces.

• Water boils at 100°C and melts at 0°C at standard pressure.

• Different substances have different boiling and melting points.

• Boiling and melting points can be used to identify substances.

Ethanol and methanol are two common types of alcohol. Ethanol has the formula C2H5OH, while methanol has the formula CH3OH.

• Ethanol formula: C2H5OH

• Methanol formula: CH3OH

pH is a measure of acidity or basicity of a solution. It is the negative logarithm of hydrogen ion concentration.

• pH ranges from 0 to 14, with 7 being neutral

• Acidic solutions have a pH less than 7, while basic solutions have a pH greater than 7

• pH can be measured using a pH meter or pH paper

• pH can also be calculated using the formula pH = -log[H+], where [H+] is the hydrogen ion concentration

I am a chemist with knowledge of pH meter, alkalinity, chloride, hardness, and TDS.

• pH meter is a device used to measure the acidity or basicity of a solution.

• Alkalinity is the capacity of water to neutralize acids.

• Chloride is a negatively charged ion commonly found in saltwater.

• Hardness refers to the amount of dissolved minerals, such as calcium and magnesium, in water.

• TDS is the total amount of dissolved solids in water, including minerals, salts, and metals.

Parameters of water analysed in lab include pH, turbidity, conductivity, dissolved oxygen, total dissolved solids, and microbial content.

• pH level

• Turbidity

• Conductivity

• Dissolved oxygen

• Total dissolved solids

• Microbial content

There are five types of fire extinguishers based on the type of fire they can extinguish.

• There are five types of fire extinguishers: water, foam, powder, CO2, and wet chemical.

• Water extinguishers are suitable for Class A fires (wood, paper, cloth, etc.)

• Foam extinguishers are suitable for Class A and B fires (flammable liquids)

• Powder extinguishers are suitable for Class A, B, and C fires (electrical fires)

• CO2 extinguishers are suitable for Class B and electrical fires

• Wet chemi...read more

pH is a measure of the acidity or alkalinity of a solution.

• pH stands for 'potential of hydrogen'.

• It is a logarithmic scale ranging from 0 to 14.

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

• pH is determined by the concentration of hydrogen ions in a solution.

• Examples: Lemon juice has a pH of around 2, while baking soda has a pH of around 9.

AFR testing is a process of measuring the air-to-fuel ratio in an engine to optimize its performance and reduce emissions.

• AFR stands for Air-Fuel Ratio

• It is commonly used in automotive and aviation industries

• The ideal AFR varies depending on the type of fuel and engine

• AFR testing can be done using a wideband oxygen sensor or a gas analyzer

Seawage water effluent is the treated wastewater that is discharged into the sea.

• Seawage water effluent is the treated wastewater that is discharged into the sea.

• It is the final product of the sewage treatment process.

• The operation and maintenance of sewage treatment plants ensure that the effluent meets the required standards before discharge.

• Effluent quality is monitored regularly to ensure compliance with environmental regulations.

• Examples of treatment processes include pr...read more

Mistakes are the first step towards learning.

• Mistakes help us identify areas of improvement.

• They provide us with valuable feedback.

• Mistakes help us develop problem-solving skills.

• They encourage us to try new things and take risks.

• Mistakes teach us resilience and perseverance.

• Examples: Thomas Edison's numerous failed attempts before inventing the light bulb, Michael Jordan's missed shots before becoming a basketball legend.

Alcoa stands for Aluminum Company of America, a leading producer of aluminum products.

• Alcoa stands for Aluminum Company of America

• It is a leading producer of aluminum products

• Founded in 1888

Various types of reactors are used in pharmaceutical industry, with GLR reactors being common. The main reaction used in pharma is typically chemical synthesis. HF gas is not used in GLR due to its corrosive nature. SSR-316 is a type of stainless steel commonly used in pharmaceutical equipment.

• Types of reactors used in pharma include GLR reactors, batch reactors, and continuous flow reactors

• Main reactions used in pharma are chemical synthesis reactions

• HF gas is not used in GL...read more

Methycobalamin is used for the treatment of vitamin B12 deficiency and related conditions.

• Methycobalamin is a form of vitamin B12 that is used to treat vitamin B12 deficiency.

• It is commonly prescribed for conditions such as pernicious anemia, neuropathy, and megaloblastic anemia.

• Methycobalamin helps in the production of red blood cells and nerve cells, and it plays a crucial role in maintaining the health of the nervous system.

• It is available in various forms such as tablets,...read more

GC is a gas chromatography instrument used for separating and analyzing volatile compounds.

• GC separates and analyzes volatile compounds based on their boiling points and affinity for the stationary phase

• It is commonly used in forensic science, environmental analysis, and pharmaceutical research

• GC can be coupled with mass spectrometry for more accurate compound identification

Total moisture refers to the amount of water present in a substance, and it can be calculated using various methods.

• Total moisture is the sum of both free and bound water in a substance.

• It is important to determine the total moisture content in materials such as food, pharmaceuticals, and chemicals.

• Methods for calculating total moisture include drying methods, Karl Fischer titration, and gravimetric analysis.

• For example, in drying methods, the substance is heated to remove th...read more

CDCl3 is important in NMR spectroscopy due to its high purity, low cost, and lack of NMR-active protons.

• CDCl3 is commonly used as a solvent in NMR spectroscopy due to its high purity, which minimizes interference with the sample being analyzed.

• CDCl3 is inexpensive and readily available, making it a cost-effective choice for routine NMR experiments.

• CDCl3 does not contain any NMR-active protons, which helps prevent unwanted signals in the NMR spectrum.

• CDCl3 has a high boiling p...read more

PH represents the concentration of hydrogen ions in a sample.

• PH is measured on a scale of 0-14, with 7 being neutral.

• A lower PH indicates higher acidity, while a higher PH indicates higher alkalinity.

• PH can be measured using a PH meter or through chemical indicators.

• The PH of a sample can affect its chemical properties and reactions.

I expect a challenging and rewarding work environment where I can utilize my skills and contribute to scientific advancements.

• I expect to work in a well-equipped laboratory with state-of-the-art instruments.

• I expect to collaborate with a team of talented scientists and researchers.

• I expect opportunities for professional development and growth.

• I expect to contribute to scientific publications and advancements.

• I expect a competitive salary and benefits package.

H2O and HCl exhibit different behaviors due to their chemical properties.

• H2O is a polar molecule, while HCl is a polar covalent molecule.

• H2O has a higher boiling point and melting point than HCl.

• HCl is a strong acid, while H2O is a neutral molecule.

• H2O can act as a solvent for many substances, while HCl is mainly used in chemical reactions.

• H2O has a higher density than HCl.

The subjects studied in MSc course depend on the specialization chosen by the student.

• The MSc course offers various specializations such as organic chemistry, inorganic chemistry, physical chemistry, analytical chemistry, etc.

• The curriculum includes both theoretical and practical aspects of the chosen specialization.

• Some common subjects include spectroscopy, quantum mechanics, thermodynamics, kinetics, etc.

• Students may also have to undertake a research project or thesis as pa...read more

Environmental testing is crucial for ensuring the safety of our surroundings and preventing harm to human health.

• Identifies potential hazards and risks to human health and the environment

• Helps in developing and implementing effective pollution control measures

• Ensures compliance with environmental regulations and standards

• Examples include testing for air and water quality, soil contamination, and hazardous waste disposal

• Environmental testing is important in industries such as ...read more

The wire used for firing in a GCV machine is typically a nichrome wire.

• Nichrome wire is commonly used in GCV machines for its high electrical resistance and ability to withstand high temperatures.

• It is often coiled or shaped into a specific design to provide efficient heating.

• Nichrome wire is also used in other applications such as heating elements in toasters, hair dryers, and electric ovens.

I will maintain housekeeping activities by implementing regular cleaning schedules, organizing workspaces, and properly disposing of waste.

• Create a cleaning schedule for daily, weekly, and monthly tasks

• Organize workspaces by labeling chemicals, storing equipment properly, and maintaining clear pathways

• Dispose of waste according to safety regulations and guidelines

• Regularly inspect and maintain equipment to ensure proper functioning

SOP preparation includes a detailed description of procedures, safety measures, and quality control measures.

• Detailed procedures for each step of the process

• Safety measures to be followed during the process

• Quality control measures to ensure consistency and accuracy

• Equipment and materials required for the process

• Training requirements for personnel involved in the process

Diesel cannot be directly made from benzene, but it can be produced through a multi-step process involving hydrogenation and isomerization.

• Diesel is typically produced from crude oil, not benzene.

• Benzene can be hydrogenated to produce cyclohexane, which can then be further processed to obtain diesel.

• The hydrogenation of benzene involves the addition of hydrogen gas in the presence of a catalyst.

• The resulting cyclohexane can undergo isomerization to produce a mixture of hydroc...read more

To prepare 0.1N HCl, dilute 8.3 mL of concentrated HCl to 1 liter with distilled water.

• Measure 8.3 mL of concentrated HCl using a graduated cylinder.

• Add the concentrated HCl to a 1 liter volumetric flask.

• Fill the flask with distilled water up to the 1 liter mark.

• Mix the solution thoroughly to ensure uniformity.

• The resulting solution will be 0.1N HCl.