Case-Based Question Bank

You are asked to prepare 250 mL of a 0.2 M NaOH solution. First, you weigh the correct amount of solid NaOH, dissolve it in some water, and then carefully adjust to exactly 250 mL. Which is the correct sequence of instruments?

• Watch glass → Volumetric flask

• Beaker → Graduated cylinder

• Erlenmeyer flask → Test tube

• Wash bottle → Plastic pipette

During a titration experiment, you need to slowly release precise volume of acid solution into an alkaline solution. Which instruments are required?

• Volumetric pipette with alkaline solution

• Pipette bulb with acid solution

• Buret with acid solution

• Wash bottle (to rinse down drops)

• Beaker with alkaline solution

Match the task with the correct instrument:

• Rinse sides of glassware

• Beaker

• Hold the solution and mix it gently

• Stirring glass rod

• Agitate a liquid in a beaker

• Erlenmeyer flask

• Hold a solution and heat it in a tripod

• Wash bottle

A student must heat 40 mL of water until it boils. Which setup is correct?

• Heat water in a volumetric flask directly over the Bunsen burner

• Place a beaker with water held by a ring stand over a Bunsen burner

• Put water in a plastic pipette and wave it over the flame

• Heat water in a test tube held with a bare hand

You need to heat at a very high termperature a small sample of copper(II) sulfate crystals to remove water of crystallization. Which instruments are suitable?

• Crucible with lid

• Wire gauze

• Bunsen burner

• Test tube

• Volumetric flask

You are asked to separate sand from salt solution. Which sequence of instruments is best?

• Beaker → Crucible → Evaporating dish

• Beaker → Funnel with filter paper → Evaporating dish

• Graduated cylinder → Wash bottle → Volumetric flask

• Watch glass → Pipette bulb → Wire gauze

To accurately weigh 2.50 g of salt, you need which instruments?

• Electronic balance

• Weighing boat or watch glass

• Spatula

• Buret

• Volumetric flask

Measure approximate liquid volume → ___

• Graduated cylinder

• Thermometer

• Balance

• Wash bottle

Avoid splashing when pouring liquid → ___

• Funnel

• Spoon

• Plate

• Cup

While mixing a solution, the beaker tips and some hot liquid spills on a student’s coat and arm. What should the student do first?

• Use the fire extinguisher

• Go immediately to the emergency shower

• Rinse with abundant water and inform an adult

• Continue the experiment