30+ Senior Chemist Interview Questions and Answers

Temperature and pressure are directly related to each other.

• As temperature increases, pressure also increases.

• As temperature decreases, pressure also decreases.

• This relationship is described by the ideal gas law, which states that the pressure of a gas is directly proportional to its temperature when volume and amount of gas are constant.

• For example, when a gas is heated, its molecules gain kinetic energy and move faster, resulting in more frequent collisions with the contain...read more

Yes, I am proficient in MS Office package including Excel, Word, and PowerPoint.

• I have used Excel for data analysis and creating spreadsheets

• I am skilled in creating professional documents using Word

• I have created presentations using PowerPoint for various purposes

• I am familiar with advanced features of MS Office such as macros and pivot tables

Strong acids completely dissociate in water, while weak acids only partially dissociate. Acids include HCl, H2SO4, HNO3, CH3COOH, and H3PO4. Bases include NaOH, KOH, NH3, Ca(OH)2, and Mg(OH)2.

• Strong acids fully dissociate in water, producing a high concentration of H+ ions. Examples include HCl (hydrochloric acid), H2SO4 (sulfuric acid), and HNO3 (nitric acid).

• Weak acids only partially dissociate in water, resulting in a lower concentration of H+ ions. Examples include CH3COO...read more

Inventory control in pharma involves managing raw materials, finished products, and packaging materials.

• Use a computerized inventory management system to track inventory levels and reorder points

• Implement a first-in, first-out (FIFO) system to ensure that older inventory is used first

• Regularly conduct physical inventory counts to identify discrepancies and prevent stockouts

• Maintain proper storage conditions to prevent spoilage or degradation of inventory

• Separate and label inv...read more

Reactions involve the transformation of one or more substances into new substances.

• Acid-base reactions involve the transfer of a proton from an acid to a base.

• Oxidation-reduction reactions involve the transfer of electrons between reactants.

• Combustion reactions involve the rapid oxidation of a fuel in the presence of oxygen.

• Hydrolysis reactions involve the breaking of a chemical bond using water.

• Esterification reactions involve the formation of an ester from a carboxylic acid...read more

Qualification process for AHU system involves handling of equipment to ensure compliance with standards.

• Qualification process involves testing and verifying the performance of AHU system.

• Equipment handling should follow standard operating procedures to prevent contamination.

• Documentation of the qualification process and equipment handling is necessary for compliance.

• Examples of equipment handling include cleaning, calibration, and maintenance.

• Qualification process should be p...read more

Acids and bases are important in chemistry. Here are some examples:

• Acids: HCl (hydrochloric acid), H2SO4 (sulfuric acid), HNO3 (nitric acid)

• Bases: NaOH (sodium hydroxide), KOH (potassium hydroxide), NH3 (ammonia)

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

• Acids donate H+ ions, while bases accept H+ ions

Alkanity is not directly associated with hardness.

• Alkanity refers to the ability of a substance to neutralize acids.

• Hardness refers to the concentration of calcium and magnesium ions in water.

• Alkanity and hardness are both important water quality parameters, but they measure different properties.

• Alkanity is measured in terms of alkaline substances like bicarbonates, carbonates, and hydroxides.

• Hardness is measured in terms of calcium and magnesium ions.

• While both alkanity and ...read more

The weight of a shoe will change if the specific gravity of the material it is made of changes.

• Specific gravity is the ratio of the density of a material to the density of a reference substance (usually water).

• If the specific gravity of the material increases, the weight of the shoe will also increase.

• Conversely, if the specific gravity decreases, the weight of the shoe will decrease.

• For example, if a shoe is made of a material with a specific gravity of 2 and then it is chan...read more

Fouling refers to the accumulation of unwanted substances on surfaces, hindering their normal function.

• Fouling is the deposition or buildup of unwanted materials on surfaces.

• It can occur in various industries, such as oil refining, chemical processing, and water treatment.

• Examples of fouling include the formation of scale in pipes, the buildup of biofilms on ship hulls, and the accumulation of dirt on solar panels.

• Fouling can reduce efficiency, increase energy consumption, an...read more

As a Sr. Chemist, I handle various types of equipment including spectrophotometers, chromatographs, balances, and reactors.

• Spectrophotometers

• Chromatographs

• Balances

• Reactors

Quality checking in oil can be maintained by following strict protocols and using advanced technology.

• Establishing standard operating procedures for quality control

• Regular testing of oil samples for purity and contaminants

• Using advanced technology such as gas chromatography and mass spectrometry

• Training staff on proper handling and testing techniques

• Maintaining a clean and controlled environment for testing

• Collaborating with external laboratories for third-party verification

• I...read more

I have 5 years of experience in the dairy industry.

• Worked as a chemist at a dairy processing plant for 3 years

• Developed new dairy products and improved existing formulations

• Conducted quality control tests on dairy products

• Collaborated with dairy farmers to ensure quality of raw materials

FDA stands for Food and Drug Administration.

• FDA is a regulatory agency in the United States.

• It is responsible for protecting public health by ensuring the safety and efficacy of food, drugs, medical devices, cosmetics, and more.

• FDA approves and regulates the manufacturing, labeling, and marketing of these products.

• It conducts inspections, enforces regulations, and sets standards for quality and safety.

• FDA also monitors and investigates reports of adverse events or side effect...read more

Phosphorous analysis involves determining the concentration of phosphorous in a sample using various analytical techniques.

• Phosphorous analysis is important in environmental monitoring to assess pollution levels.

• Common methods for phosphorous analysis include colorimetric assays, spectrophotometry, and ion chromatography.

• Phosphorous can exist in different forms such as orthophosphate, polyphosphate, and organic phosphorous compounds.

• Accurate phosphorous analysis is crucial in...read more

I prioritize safety by following proper protocols, conducting regular maintenance, and ensuring all team members are trained on equipment usage.

• Regularly inspecting equipment for any signs of wear or damage

• Following all safety protocols and guidelines provided by the manufacturer

• Ensuring all team members are properly trained on equipment usage and safety procedures

• Reporting any safety concerns or issues immediately to the appropriate personnel

Iodine value is a measure of the unsaturation of fatty acids in oil.

• It is the amount of iodine, in grams, that is absorbed by 100 grams of oil.

• It indicates the degree of unsaturation of fatty acids in the oil.

• Oils with high iodine values are more reactive and prone to oxidation.

• Iodine value is used to determine the quality and purity of oils.

• For example, coconut oil has an iodine value of 7, while soybean oil has an iodine value of 130-140.

Chemical consumption in sludge dewatering is crucial for efficient treatment processes.

• Chemical consumption depends on the type of sludge being treated (e.g. activated sludge, primary sludge)

• The dosage of chemicals like coagulants and flocculants should be optimized for cost-effectiveness

• Monitoring and adjusting chemical consumption based on sludge characteristics and treatment goals is important

Increasing pH in boiler prevents corrosion and scaling.

• Higher pH levels reduce the acidity of water, preventing corrosion of metal pipes and equipment.

• Scaling caused by minerals in water is also reduced at higher pH levels.

• Optimal pH levels vary depending on the type of boiler and water source.

• Chemical additives can be used to adjust pH levels in boilers.

• Maintaining proper pH levels can improve boiler efficiency and lifespan.

Treatment is necessary to cure a disease or condition, while non-treatment can lead to worsening of the condition.

• Treatment helps to alleviate symptoms and improve quality of life

• Non-treatment can lead to complications and even death

• Treatment may involve medication, therapy, or surgery depending on the condition

• Examples include chemotherapy for cancer, antibiotics for infections, and physical therapy for injuries

O&M refers to operations and maintenance tasks in a chemical plant. It involves ensuring smooth functioning of equipment and processes.

• Develop a detailed schedule for routine maintenance tasks

• Regularly inspect equipment for signs of wear and tear

• Train staff on proper operation and maintenance procedures

• Implement a system for tracking maintenance activities and repairs

• Prioritize safety protocols to prevent accidents and ensure compliance with regulations

Handle client visits by preparing in advance, being professional and attentive, and following up afterwards.

• Prepare in advance by researching the client's background and needs

• Be professional by dressing appropriately and speaking confidently

• Be attentive by actively listening to the client's concerns and addressing them

• Follow up afterwards with a thank you note or email to show appreciation

ANFD is operated by controlling temperature, pressure, and agitation to facilitate efficient separation of components in a mixture.

• Control temperature using a heating or cooling system to maintain desired conditions.

• Adjust pressure using valves to optimize separation process.

• Regulate agitation speed to ensure proper mixing and distribution of components.

• Monitor process parameters closely to prevent any deviations.

• Example: ANFD is commonly used in chemical industries for cryst...read more

PPE is essential for safety during chemical processes.

• Identify the specific hazards of the process and select appropriate PPE.

• Ensure PPE is properly fitted and worn correctly.

• Regularly inspect and maintain PPE to ensure effectiveness.

• Examples of PPE include gloves, goggles, respirators, and protective clothing.

• Train employees on proper use and disposal of PPE.

GMP stands for Good Manufacturing Practice and GDP stands for Good Distribution Practice. They are guidelines that ensure quality and safety in the production and distribution of pharmaceutical products.

• GMP focuses on manufacturing processes to ensure product quality and safety

• GDP focuses on distribution processes to ensure product quality and safety during transportation and storage

• Both GMP and GDP are essential in the pharmaceutical industry to maintain high standards and c...read more

PP modules in SAP are used for production planning and control.

• PP stands for Production Planning.

• PP modules in SAP help in planning and controlling the production process.

• It includes functions like material requirements planning, capacity planning, and production scheduling.

• PP modules also integrate with other SAP modules like MM (Materials Management) and SD (Sales and Distribution).

Testing parameters refer to the specific conditions and variables used in conducting experiments or analyses.

• Testing parameters include factors such as temperature, pressure, pH, concentration, and time.

• These parameters are crucial in determining the accuracy and reliability of test results.

• For example, in a chemical reaction, the temperature and concentration of reactants are important testing parameters.

• Adjusting testing parameters can help optimize experimental conditions ...read more

Solvents are substances capable of dissolving other substances.

• Solvents can be polar or non-polar

• Common solvents include water, acetone, ethanol, and hexane

• Solvents can be used for cleaning, dissolving, or extracting substances

Troubleshooting instruments involves identifying and resolving issues with equipment used in chemical analysis.

• Identify the specific issue with the instrument

• Check for any error messages or abnormal readings

• Consult instrument manuals or technical support for guidance

• Perform routine maintenance and calibration

• Consider environmental factors that may affect instrument performance

Phosphorus procedure involves the determination of phosphorus content in a sample using various analytical techniques.

• Sample preparation involves digestion of the sample with acid

• Phosphorus can be determined using colorimetric methods or by ICP-OES

• Interference from other elements like iron and aluminum must be accounted for

• Phosphorus analysis is important in environmental monitoring and agricultural research

MEA is preferred over DEA due to its lower toxicity and better performance in CO2 capture.

• MEA has a lower toxicity compared to DEA, making it safer to handle.

• MEA has a higher reactivity with CO2, resulting in better CO2 capture efficiency.

• MEA has a higher boiling point than DEA, making it more stable at higher temperatures.

• MEA is more expensive than DEA, but its superior performance justifies the cost.

Coal analysis standard is a method used to determine the composition and quality of coal.

• Coal analysis standard involves various tests and measurements to determine the properties of coal.

• It helps in assessing the energy content, moisture content, sulfur content, and other important parameters of coal.

• Different standards like ASTM, ISO, and BIS provide guidelines for conducting coal analysis.

• Methods used in coal analysis include proximate analysis, ultimate analysis, calorifi...read more

Water treatment procedure involves various steps to remove impurities and ensure safe drinking water.

• The first step is coagulation, where chemicals are added to the water to make impurities clump together.

• Next is sedimentation, where the clumped impurities settle at the bottom of the water.

• Filtration follows, where the water passes through layers of sand, gravel, and charcoal to remove smaller particles.

• Disinfection is then done using chlorine or other disinfectants to kill a...read more

Chemicals are used in various industries such as pharmaceuticals, agriculture, manufacturing, and research.

• Pharmaceuticals - for drug development and production

• Agriculture - for fertilizers, pesticides, and herbicides

• Manufacturing - for producing plastics, textiles, and chemicals

• Research - for conducting experiments and testing new products

Shoe size is not solely determined by foot length, as factors like width and shape of the foot also play a role.

• Shoe size is a measurement of the length of the foot, but it also takes into account width and shape.

• Different shoe brands may have slightly different sizing charts, so it's important to try on shoes before purchasing.

• For example, someone with a size 8 foot may wear a size 8 in one brand but a size 8.5 in another brand due to variations in fit.