10+ QC Lab Chemist Interview Questions and Answers

Distillation is a process of separating components of a mixture based on their boiling points.

• Distillation involves heating a mixture to vaporize the more volatile component, which is then condensed and collected.

• The diagram typically shows a distillation flask, condenser, and collection flask.

• Cracking is a process of breaking down larger hydrocarbon molecules into smaller ones.

• During Corona, I utilized my time by taking online courses, reading scientific literature, and prac...read more

1 cm = 10 mm

• 1 cm is equal to 10 mm

• To convert cm to mm, multiply the value in cm by 10

• For example, 5 cm is equal to 50 mm (5 cm x 10 = 50 mm)

Specific gravity is the ratio of the density of a substance to the density of a reference substance.

• Specific gravity is a unitless measurement that compares the density of a substance to the density of a reference substance (usually water).

• It is commonly used in chemistry to determine the purity of a substance or to identify an unknown substance.

• The specific gravity of water is 1.0, so substances with a specific gravity greater than 1.0 are denser than water, while those with...read more

Hydrogen sulfide is produced when hydrogen reacts with sulfur.

• The chemical equation for the reaction is: H2 + S -> H2S

• Hydrogen sulfide is a toxic gas with a characteristic rotten egg odor.

• The reaction can occur in various industrial processes, such as oil refining and wastewater treatment.

• Hydrogen sulfide can also be produced by bacteria in natural environments, such as swamps and hot springs.

Acidity and basicity are properties of substances that determine their ability to donate or accept protons.

• Acidity refers to the ability of a substance to donate protons (H+ ions). Acids increase the concentration of H+ ions in a solution.

• Basicity refers to the ability of a substance to accept protons. Bases increase the concentration of OH- ions in a solution.

• Acidity and basicity are measured on the pH scale, which ranges from 0 to 14. A pH of 7 is considered neutral, below ...read more

The temperature in the ICP-MS lens can vary depending on the specific instrument and analysis being performed.

• The temperature in the ICP-MS lens is typically controlled by the instrument's software.

• The temperature can range from room temperature to several hundred degrees Celsius.

• Higher temperatures can help reduce matrix effects and improve sensitivity.

• However, excessively high temperatures can cause instrument damage or sample degradation.

• It is important to optimize the len...read more

Resistance is measured using a multimeter by applying a known voltage and measuring the resulting current.

• Use a multimeter to measure resistance

• Set the multimeter to the resistance (ohms) setting

• Connect the probes to the material or component being tested

• Apply a known voltage and measure the resulting current

• Calculate resistance using Ohm's Law: R = V/I

Percentage can be found by dividing the part by the whole and multiplying by 100.

• To find percentage, divide the part by the whole and multiply by 100.

• For example, to find 20% of 50, calculate (20/100) * 50 = 10.

Yes, I am experienced in handling HPLC instruments.

• I have experience in operating and maintaining HPLC instruments.

• I am familiar with troubleshooting and resolving issues related to HPLC.

• I have knowledge of various HPLC techniques and methods.

• I am proficient in using HPLC software and analyzing data.

• For example, in my previous job, I was responsible for running HPLC tests on pharmaceutical products and ensuring the accuracy of results.