High School

1. Describe what an abstract is?

2. List any four glassware used in a chemical lab.

3. During laboratory organization, verification of equipment and chemicals is one of the important activities which take place, in form of stock. Give four types of stock that take place in a laboratory.

4. How is laboratory management different from laboratory organization?

5. Any chemical laboratory has got rules and regulations. Give any six rules which are supposed to be adhered to in a chemical lab.

6. Imagine you are working in a quality control laboratory at Castel Malawi Limited and you want to prepare 0.5 M of sodium hydroxide solution in 1000 mL, given sodium hydroxide pellets with an assay of 96%. Describe step-wisely how you can do that.

7. During chemical dilution, the equation C1.V1 = C2.V2 is frequently used.

Answer :


  1. What is an abstract?

    An abstract is a brief summary of a research article, thesis, review, or any in-depth investigation in a scientific field. It serves to provide the reader with a quick overview of the main points and results of the research, helping them to decide whether to read the full document. An abstract typically includes the purpose of the research, the methodology, the main findings, and the conclusion.


  2. List any four glassware used in a chemical lab.

    Here are four common types of glassware used in a chemical lab:


    1. Beaker

    2. Erlenmeyer flask

    3. Graduated cylinder

    4. Burette



  3. Give four types of stock that take place in a laboratory.

    Types of stock that are managed in a laboratory include:


    1. Chemical stock: Keeping track of the chemicals available and their quantities.

    2. Equipment stock: Inventory of laboratory instruments and equipment.

    3. Consumables stock: Managing items like gloves, pipettes, and paper towels that need regular replenishment.

    4. Reagent stock: Ensuring that necessary reagents are available in planned quantities for experiments.



  4. How is laboratory management different from laboratory organization?

    Laboratory management involves planning, directing, and coordinating the operations of the laboratory, including setting goals, managing staff, budgeting, and ensuring laboratory safety.

    Laboratory organization focuses more on the arrangement and maintenance of the physical aspect of the lab, such as organizing workspaces, ensuring cleanliness, and properly labeling shelves and containers.


  5. Give any six rules which are supposed to be adhered to in a chemical lab.

    Chemical lab rules often include:


    1. Always wear appropriate personal protective equipment (PPE), such as lab coats, gloves, and safety goggles.

    2. Do not eat, drink, or apply cosmetics in the lab.

    3. Clearly label all containers with their contents and hazard warnings.

    4. Know the location of safety equipment like eyewash stations, fire extinguishers, and first aid kits.

    5. Dispose of chemical waste according to the lab's guidelines.

    6. Never work alone in the lab without proper supervision.



  6. Describe step-by-step how you can prepare 0.5 M of sodium hydroxide solution in 1000 mL, given sodium hydroxide pellets with an assay of 96%.

    To prepare a 0.5 M NaOH solution:


    • First, calculate the molar mass of NaOH, which is approximately 40 g/mol.

    • Determine the mass required: Molarity [tex](M) \times \text{Volume in Liters} \times \text{Molar Mass}[/tex]. Here, it's [tex]0.5 \times 1 \times 40 = 20 \, \text{g}[/tex].

    • Adjust for purity: Divide by the assay ([tex]96\%[/tex] purity), so you’ll need [tex]\frac{20}{0.96} \approx 20.83 \, \text{g}[/tex] of NaOH pellets.

    • Carefully weigh out 20.83 g of the pellets using a balance.

    • Dissolve the NaOH pellets in about 800 mL of distilled water, stirring until completely dissolved.

    • Once dissolved, transfer the solution to a 1000 mL volumetric flask and add distilled water until the bottom of the meniscus reaches the 1000 mL mark.



  7. Explain the equation [tex]C_1V_1 = C_2V_2[/tex] used in chemical dilution.

    The equation [tex]C_1V_1 = C_2V_2[/tex] is used to calculate dilutions, where [tex]C_1[/tex] and [tex]V_1[/tex] are the concentration and volume of the stock solution, while [tex]C_2[/tex] and [tex]V_2[/tex] are the concentration and volume after dilution. This equation helps in determining the volume of a concentrated solution required to make a less concentrated one.


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