100+ Chemist Interview Questions and Answers

UV-FT-IR, NMR principles involve interaction of molecules with electromagnetic radiation to provide structural information.

• UV-FT-IR spectroscopy involves measuring the absorption of ultraviolet and infrared radiation by molecules to determine functional groups and chemical structure.

• NMR spectroscopy utilizes the magnetic properties of certain atomic nuclei to provide information about the molecular structure and environment.

• Both techniques rely on the interaction of molecules...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.

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

Raw materials used in polyester include petroleum, coal, air, and water.

• Polyester is made from a chemical reaction between an acid and an alcohol.

• The acid used is typically terephthalic acid or dimethyl terephthalate.

• The alcohol used is typically ethylene glycol.

• Other raw materials used in the production of polyester include catalysts and stabilizers.

• Polyester production is heavily reliant on petroleum and coal as sources of raw materials.

Material testing involves analyzing the physical and chemical properties of materials to determine their suitability for specific applications.

• Material testing can include tests for strength, durability, corrosion resistance, and thermal properties.

• Common methods of material testing include tensile testing, hardness testing, and spectroscopy.

• Material testing is important in industries such as construction, aerospace, and automotive manufacturing.

• Testing can also be done on ma...read more

APQR stands for Annual Product Quality Review. It is a comprehensive report that evaluates the quality of a pharmaceutical product.

• APQR is a mandatory requirement for pharmaceutical companies to ensure the quality of their products.

• It includes a review of the manufacturing process, quality control, and any deviations or changes made during the year.

• The report also includes an analysis of product complaints, stability data, and any recalls or regulatory actions taken.

• APQR is s...read more

Various lab instruments are used in chemistry experiments and analysis.

• Spectrophotometer: measures the intensity of light absorbed or emitted by a sample

• Centrifuge: separates substances of different densities using centrifugal force

• pH meter: measures the acidity or alkalinity of a solution

• Bunsen burner: provides a controlled flame for heating substances

• Microscope: magnifies and visualizes small samples

• Gas chromatograph: separates and analyzes components of a mixture

• Balance: m...read more

The new code IS 10262 has updated guidelines for concrete mix design.

• The new code provides revised recommendations for water-cement ratio.

• It includes updated specifications for aggregate grading.

• There are changes in the guidelines for admixtures usage.

• The code now emphasizes on the importance of testing and quality control measures.

• Example: The new code specifies a maximum water-cement ratio of 0.45 for reinforced concrete.

• Example: It recommends a minimum cement content of 30...read more

No, as a Chemist, I do not have the qualifications or experience to drive a GCV.

• I do not have the necessary training or license to operate a GCV.

• My expertise lies in chemistry, not driving heavy vehicles.

• Driving a GCV requires specific skills and qualifications that I do not possess.

Yes, I can operate the GCV.

• I have experience operating the GCV.

• I am familiar with the controls and procedures of the GCV.

• I have successfully operated the GCV in previous roles.

• I can demonstrate my skills and knowledge in operating the GCV.

Yield can be calculated by dividing the actual amount of product obtained by the theoretical amount that could be obtained.

• Determine the amount of product obtained through experiment

• Calculate the theoretical yield based on stoichiometry

• Divide the actual yield by the theoretical yield and multiply by 100 to get the percentage yield

• Yield = (Actual yield / Theoretical yield) x 100%

pH is a measure of acidity or alkalinity of a solution. It is calculated using the formula pH = -log[H+].

• pH ranges from 0 (most acidic) to 14 (most alkaline)

• Neutral pH is 7

• pH of 0.01N NaOH can be calculated using the formula pH = -log(0.01) = 2

Shade matching is the process of selecting the appropriate color of dental restorative material to match the color of the patient's natural teeth.

• Shade matching is important in cosmetic dentistry.

• It involves using shade guides to match the color of the patient's teeth.

• Factors that can affect shade matching include lighting, patient age, and tooth translucency.

• Digital shade matching technology is also available.

• Shade matching is crucial for achieving a natural-looking result i...read more

MSDS stands for Material Safety Data Sheet. It provides information about the hazards, handling, storage, and emergency procedures for a chemical substance.

• MSDS is a document that contains detailed information about a chemical substance.

• It includes information about the physical and chemical properties of the substance.

• MSDS provides instructions for safe handling, storage, and disposal of the substance.

• It also includes information about potential hazards, such as fire, toxici...read more

I know various parameters related to chemistry such as temperature, pressure, concentration, pH, etc.

• Temperature

• Pressure

• Concentration

• pH

• Molarity

• Molality

• Density

• Viscosity

• Refractive index

Acid is a substance that donates protons and bases accept protons. They are commonly found in chemistry and have various applications.

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

• Bases are substances that accept hydrogen ions (H+) or donate hydroxide ions (OH-) when dissolved in water.

• Acids have a sour taste and can corrode metals.

• Bases have a bitter taste and feel slippery.

• Examples of acids include hydrochloric acid (HCl) and sulfuric acid (H2...read more

Lab analysis of water monitoring involves testing water samples for various contaminants and pollutants.

• Water samples are collected from various sources such as rivers, lakes, and groundwater.

• The samples are then tested for parameters such as pH, turbidity, dissolved oxygen, and various contaminants such as heavy metals, pesticides, and bacteria.

• The results of the analysis are used to determine the quality of the water and whether it is safe for human consumption or other use...read more

Sewage waste water network is a system of pipes and treatment plants that collect and treat wastewater from homes and businesses.

• It includes pipes, pumps, and treatment plants that collect and treat wastewater

• The treated water is then released back into the environment or reused for irrigation or other purposes

• The network is designed to prevent the contamination of water sources and protect public health

• Examples of sewage waste water networks include municipal sewer systems a...read more

Various methods are used to clean dirty water, including filtration, sedimentation, disinfection, and reverse osmosis.

• Filtration involves passing water through a physical barrier, such as sand or activated carbon, to remove impurities.

• Sedimentation allows heavier particles to settle to the bottom of a container, leaving cleaner water on top.

• Disinfection involves using chemicals or UV light to kill bacteria and other microorganisms.

• Reverse osmosis uses a semi-permeable membran...read more

Water can be treated through various methods such as filtration, disinfection, and chemical treatment.

• Filtration involves removing impurities and particles from water using a physical barrier.

• Disinfection involves killing or inactivating harmful microorganisms in water using chemicals or UV light.

• Chemical treatment involves adding chemicals to water to remove impurities or adjust pH levels.

• Examples of water treatment methods include reverse osmosis, chlorination, and ozonatio...read more

A spectrometer is a device used to measure the intensity of light at different wavelengths. It operates based on the principle of spectroscopy.

• Calibrate the spectrometer using known standards to ensure accurate measurements

• Select the appropriate wavelength range and resolution for the analysis

• Insert the sample into the spectrometer and record the spectrum

• Interpret the spectrum to identify compounds or analyze concentrations

• Principle: Spectroscopy involves the interaction of e...read more

AFR stands for Air Fuel Ratio, a critical parameter in combustion processes.

• AFR is the ratio of air to fuel in an internal combustion engine.

• It is measured using a device called an oxygen sensor.

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

• A lean AFR (more air, less fuel) can improve fuel efficiency but may cause engine damage.

• A rich AFR (more fuel, less air) can improve performance but may increase emissions.

• AFR is important for optimizing engine performance...read more

I have worked as a chemist for 5 years in a pharmaceutical company.

• Developed and validated analytical methods for drug products

• Conducted stability studies to support product shelf-life

• Collaborated with cross-functional teams to troubleshoot manufacturing issues

• Maintained laboratory equipment and ensured compliance with safety regulations

The temperature and humidity of the PPA area should be controlled and monitored to ensure proper storage conditions.

• Temperature should be maintained between 20-25°C

• Humidity should be maintained between 40-60%

• Excessive temperature or humidity can lead to degradation of PPA

• Regular monitoring and recording of temperature and humidity levels is necessary

Safety refers to the measures taken to prevent harm or danger to people, property, or the environment.

• Safety involves identifying and assessing potential hazards

• It requires implementing measures to control or eliminate those hazards

• It also involves training and educating individuals on safe practices

• Examples include wearing personal protective equipment, following safety protocols, and conducting regular safety inspections

The formula of Benzene is C6H6.

• Benzene is a cyclic hydrocarbon with a ring of six carbon atoms and six hydrogen atoms.

• The molecular formula of Benzene is C6H6.

• Benzene is represented as a hexagon with a circle inside to indicate delocalized electrons.

The formula of sulphuric acid is H2SO4.

• The formula of sulphuric acid consists of hydrogen (H), sulfur (S), and oxygen (O) atoms.

• It is a strong mineral acid with the chemical formula H2SO4.

• Sulphuric acid is commonly used in various industrial processes such as in batteries, fertilizers, and chemical synthesis.

Toluene is a colorless liquid with a benzene ring and a methyl group attached.

• Toluene has a chemical formula of C7H8

• It consists of a benzene ring with a methyl group attached

• The molecular structure of toluene is represented as C6H5CH3

TM stands for trademark, a symbol used to indicate that a particular product or service is legally protected.

• TM is used to protect logos, brand names, and slogans from being used by others without permission.

• It does not provide as much legal protection as a registered trademark (R), but still offers some level of protection.

• TM symbol can be used even before a trademark is officially registered.

• Example: Nike uses the TM symbol next to its logo to indicate that it is a protecte...read more

Apicore offers high-quality products, reliable services, and cost-effective solutions compared to other options.

• Apicore has a strong reputation for producing high-quality chemicals.

• Apicore provides reliable services and support to customers.

• Apicore offers cost-effective solutions for various chemical needs.

• Apicore has a track record of meeting deadlines and delivering on promises.

X factor in IS 10262 2019 refers to the factor used to calculate the water content in concrete mix design.

• X factor is used to determine the water content required for a specific workability of concrete.

• It takes into account factors such as the grading of aggregates, maximum size of aggregate, and the type of cement used.

• The X factor is calculated using a formula specified in IS 10262 2019.

• For example, a higher X factor would result in a higher water content in the concrete mi...read more

The method of determining the N/10 factor of K2Cr2O7 involves titrating it against a known concentration of a reducing agent.

• Prepare a solution of K2Cr2O7 of known concentration (N/10)

• Titrate the K2Cr2O7 solution against a reducing agent of known concentration

• Calculate the N/10 factor using the volume of the reducing agent used in the titration

• The N/10 factor is the ratio of the normality of K2Cr2O7 to the normality of the reducing agent

Oxalic acid is used for silica because it forms stable complexes with silica, aiding in its dissolution and removal.

• Oxalic acid forms stable complexes with silica, facilitating its dissolution

• It helps in removing silica deposits from surfaces

• Oxalic acid is commonly used in cleaning products for removing silica-based stains

To prepare a 1% solution, dissolve 1 gram of the solute in 100 mL of the solvent.

• Measure 1 gram of the solute using a balance

• Add the solute to a volumetric flask

• Add 100 mL of the solvent to the flask

• Mix the solution thoroughly until the solute is completely dissolved

Risk management is important to identify, assess, and prioritize risks to minimize their impact on the organization.

• Identifying potential risks and hazards

• Assessing the likelihood and severity of risks

• Prioritizing risks based on their impact

• Developing strategies to mitigate or avoid risks

• Regularly reviewing and updating risk management plans

• Examples: chemical spills, equipment failure, workplace accidents

Tablets and capsules are common forms of medication delivery in the pharmaceutical industry.

• Tablets are solid dosage forms made by compressing or molding a drug with excipients.

• Capsules are solid dosage forms in which the drug is enclosed in a gelatin shell.

• Calculation in chemistry involves performing mathematical operations to determine quantities or properties.

• Chemical formulas represent the types and numbers of atoms in a molecule.

• Examples: Tablet - Aspirin tablet, Capsule...read more

HVAC stands for Heating, Ventilation, and Air Conditioning.

• HVAC is a system used to control the temperature, humidity, and air quality in a building.

• It includes heating, cooling, ventilation, and air filtration systems.

• HVAC systems are commonly used in residential, commercial, and industrial buildings.

• Examples of HVAC equipment include air conditioners, furnaces, boilers, and ductwork.

• Proper maintenance of HVAC systems is important for energy efficiency and indoor air quality...read more

FTIR stands for Fourier Transform Infrared Spectroscopy, a technique used to analyze the chemical composition of materials.

• FTIR is a technique used to identify and analyze the chemical composition of materials based on the absorption of infrared radiation.

• It measures the absorption of different wavelengths of infrared light by a sample.

• FTIR can be used in various industries such as pharmaceuticals, food and beverage, polymers, and environmental analysis.

• It is a non-destructiv...read more

HPLC system suitability parameters ensure the system is functioning properly for accurate results.

• HPLC system suitability parameters include resolution, retention time, peak symmetry, and tailing factor.

• These parameters are used to assess the performance of the HPLC system and ensure reliable results.

• For example, resolution should be greater than 1.5, retention time should be consistent, peak symmetry should be close to 1, and tailing factor should be less than 2.

Coal is a fossil fuel formed from plant material that has been subjected to high pressure and heat over millions of years.

• Coal is primarily composed of carbon, along with small amounts of other elements like sulfur, hydrogen, oxygen, and nitrogen.

• There are different types of coal based on their carbon content and energy value, such as anthracite, bituminous, and lignite.

• Coal is used as a fuel for power generation, industrial processes, and heating.

• Coal mining can have environ...read more

There are several types of cleaning methods, including physical cleaning, chemical cleaning, and biological cleaning.

• Physical cleaning involves removing dirt and grime through scrubbing, wiping, or vacuuming.

• Chemical cleaning uses cleaning agents like detergents or solvents to break down and remove dirt and stains.

• Biological cleaning involves using enzymes or bacteria to break down organic matter, like in septic tanks or composting.

• Other types of cleaning include dry cleaning...read more

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

• pH stands for 'potential of Hydrogen'

• pH scale ranges from 0 (most acidic) to 14 (most alkaline)

• Neutral pH is 7, like pure water

• Acids have pH below 7, bases have pH above 7

• pH is important in various industries like agriculture, food, and medicine

New technologies in refining processes have advanced the industry.

• Advanced catalysts are being developed to improve efficiency and reduce environmental impact.

• Ionic liquids are being explored as alternatives to traditional solvents.

• Nanotechnology is being used to create more effective membranes for separation processes.

• Process intensification techniques are being implemented to reduce energy consumption and increase productivity.

• Digitalization and automation are being used to...read more

Anode and cathode are electrodes used in electrochemical cells to facilitate the flow of electrons.

• Anode is the electrode where oxidation occurs and electrons are lost.

• Cathode is the electrode where reduction occurs and electrons are gained.

• In a battery, the anode is the negative terminal and the cathode is the positive terminal.

• In an electrolytic cell, the anode is the positive terminal and the cathode is the negative terminal.

Parameters for clarified water include turbidity, pH, conductivity, and total dissolved solids.

• Turbidity should be less than 1 NTU

• pH should be between 6.5 and 8.5

• Conductivity should be less than 1000 µS/cm

• Total dissolved solids should be less than 500 mg/L

Titrations are used to determine the concentration of a substance in a solution. There are several types of titrations.

• Acid-base titration

• Redox titration

• Complexometric titration

• Precipitation titration

• Non-aqueous titration

Yes, I have experience with making charging calculations in my previous roles.

• I have experience with calculating charging rates for various chemical reactions.

• I am familiar with using formulas and equations to determine the amount of charge needed for a reaction.

• I have successfully calculated charging requirements for different types of batteries and electrolysis processes.