20+ QA QC Chemist Interview Questions and Answers

Molarity is the number of moles of solute in one litre of solution, while molality is the number of moles of solute in one kilogram of solvent.

• Molarity is expressed in moles per litre (mol/L), while molality is expressed in moles per kilogram (mol/kg).

• Molarity is temperature dependent due to volume changes, while molality is temperature independent.

• Molarity is commonly used in laboratory settings, while molality is used in calculations involving colligative properties.

• Example...read more

HPLC and GC are analytical techniques used to separate and quantify components in a mixture based on their physical and chemical properties.

• HPLC stands for High Performance Liquid Chromatography and GC stands for Gas Chromatography.

• HPLC uses a liquid mobile phase and a solid stationary phase to separate components based on their polarity, while GC uses a gas mobile phase and a solid or liquid stationary phase to separate components based on their boiling points.

• Beer Lambert l...read more

Qualitative analysis focuses on properties and characteristics, while quantitative analysis measures quantities and amounts.

• Qualitative analysis determines the presence or absence of a substance, while quantitative analysis determines the amount of a substance.

• Qualitative analysis is descriptive, while quantitative analysis is numerical.

• Qualitative analysis is used to identify unknown substances, while quantitative analysis is used to determine the concentration of known subs...read more

Technical skills refer to the specific knowledge and abilities required to perform tasks related to a particular field or profession.

• Technical skills are practical and hands-on abilities that are acquired through training, education, and experience.

• They involve the use of tools, equipment, software, and techniques specific to a particular field.

• Examples of technical skills for a QA QC Chemist may include proficiency in analytical instruments, knowledge of quality control proc...read more

HPLC principle is based on the separation of compounds using a liquid mobile phase and a solid stationary phase.

• HPLC stands for High Performance Liquid Chromatography.

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

• The principle involves the separation of compounds based on their interaction with the stationary phase.

• The mobile phase, usually a liquid solvent, carries the sample through the stationary phase.

• Different compounds interact differently with ...read more

The elements in 1 to 10 are Hydrogen, Helium, Lithium, Beryllium, Boron, Carbon, Nitrogen, Oxygen, Fluorine, Neon.

• Hydrogen

• Helium

• Lithium

• Beryllium

• Boron

• Carbon

• Nitrogen

• Oxygen

• Fluorine

• Neon

Technical knowledge refers to the understanding and expertise in a specific field or subject, including its principles, theories, and practical applications.

• Technical knowledge involves having a deep understanding of the subject matter and being able to apply it effectively.

• It includes knowledge of the principles, theories, and concepts related to the field.

• Technical knowledge also encompasses practical skills and hands-on experience in using tools, equipment, and techniques ...read more

Beer's law, also known as the Beer-Lambert law, describes the relationship between the concentration of a solute in a solution and the amount of light absorbed by the solution.

• Beer's law states that the absorbance of a solution is directly proportional to the concentration of the solute.

• It is commonly used in spectrophotometry to determine the concentration of a substance in a solution.

• The equation for Beer's law is A = εcl, where A is the absorbance, ε is the molar absorptiv...read more

A production chemist is responsible for developing and implementing processes to manufacture chemical products efficiently and safely.

• Developing and optimizing chemical processes for manufacturing

• Ensuring product quality and consistency through testing and analysis

• Collaborating with other departments to troubleshoot issues and improve processes

• Following safety protocols and regulations to maintain a safe working environment

The question is asking about whose reference is being used in a particular context.

• Identify the specific reference being mentioned in the context of the question.

• Consider the source or origin of the reference being discussed.

• Clarify any confusion by asking for more details or examples if needed.

Vitamins and proteins are essential nutrients for the body's overall health and functioning.

• Vitamins are organic compounds that are essential for normal growth and metabolism. Examples include Vitamin C, Vitamin D, and Vitamin B12.

• Proteins are macromolecules made up of amino acids that are crucial for building and repairing tissues. Examples include meat, dairy, and legumes.

Calibration and handling of instruments are crucial for accurate and reliable results in QA QC chemistry.

• Regular calibration of instruments is necessary to ensure accuracy and precision.

• Proper handling of instruments is important to prevent damage and maintain their performance.

• Documentation of calibration and maintenance procedures is essential for traceability and quality control.

• Examples of instruments that require calibration include pH meters, balances, and spectrophotom...read more

Synthesis of a chemical reaction involves combining reactants to form products through a series of steps.

• Identify reactants and products

• Determine the stoichiometry of the reaction

• Select appropriate reaction conditions (temperature, pressure, catalyst)

• Follow reaction mechanism to understand the steps involved

• Purify and isolate the final product

PH value is a measure of the acidity or alkalinity of a solution on a scale of 0-14.

• PH value below 7 indicates acidity, while above 7 indicates alkalinity

• Neutral PH is 7, like pure water

• PH value can affect chemical reactions and biological processes

Log H+ is the logarithm of the concentration of hydrogen ions in a solution.

• Log H+ is used to measure the acidity of a solution.

• It is calculated as the negative logarithm of the concentration of hydrogen ions in moles per liter.

• For example, a solution with a hydrogen ion concentration of 1 x 10^-7 M would have a log H+ of 7.

Inorganic chemistry is the branch of chemistry that deals with the study of inorganic compounds, which do not contain carbon-hydrogen bonds.

• Focuses on elements other than carbon

• Studies properties and behavior of inorganic compounds

• Includes metals, minerals, and non-carbon containing compounds

• Examines reactions and synthesis of inorganic substances

Organic chemistry is the branch of chemistry that deals with the study of carbon-containing compounds.

• Focuses on the structure, properties, composition, reactions, and synthesis of carbon-based compounds

• Includes the study of hydrocarbons, alcohols, acids, esters, and more

• Important in pharmaceuticals, petrochemicals, plastics, and other industries

Edible oil is a plant, animal, or synthetic fat used in cooking or frying food.

• Edible oils can be derived from various sources such as soybean, sunflower, palm, coconut, olive, etc.

• They are used for cooking, frying, baking, and as a salad dressing.

• Edible oils are rich in essential fatty acids and vitamins.

• They have different smoke points, which determine their suitability for different cooking methods.

• Some common types of edible oils are vegetable oil, canola oil, peanut oil,...read more

I decided to change because I wanted to grow professionally and learn new skills.

• Desire for professional growth

• Opportunity to learn new skills

• Seeking new challenges

• Better work-life balance

• Company culture or values misalignment

Chemical names are unique identifiers for specific substances used in chemistry.

• Chemical names can be systematic (following specific rules) or common (based on historical usage)

• Examples of chemical names include: sodium chloride, hydrogen peroxide, sulfuric acid

Acids react with bases to form salts and water.

• Acids react with bases to form salts and water

• Acids can also react with metals to form hydrogen gas and a salt

• Strong acids like hydrochloric acid can react with carbonates to form carbon dioxide gas, water, and a salt

Ammonia reacts with acids to form ammonium salts, with metals to form amides, and with halogens to form salts.

• Ammonia reacts with acids to form ammonium salts (e.g. NH3 + HCl -> NH4Cl)

• Ammonia reacts with metals to form amides (e.g. 2NH3 + 2Na -> 2NaNH2 + H2)

• Ammonia reacts with halogens to form salts (e.g. NH3 + HCl -> NH4Cl)