1) making up standard solution and acid base titration

Question 1

What is a standard solution?

Answer 1

A standard solution is a solution of known concentration.

Question 2

How do you make a standard solution?

Answer 2

● Measure, using a balance, the mass of solid required.
● Transfer this to a volumetric flask and rinse the remaining
weighing bottle content (with distilled water) into the flask
so no solid is lost.
● Add a volume of distilled water to dissolve the solid. Swirl
to mix.
● Then add more distilled water up to the line on the
volumetric flask. Invert multiple times to mix.

Question 3

What is the weighing by difference technique?

Answer 3

● It is a method to weigh materials accurately.
● Mass of substance = Mass of weighing dish and substance - Mass of dish after substance has been transferred.

Question 4

What equipment is used to carry out a titration?

Answer 4

● A pipette and pipette filler are used to accurately measure out the volume of a reactant before transferring it to a conical flask.
● A burette is used to add small volumes of one reactant to the other reactant (until the reaction has reached completion).

Question 5

How do you carry out a titration?

Answer 5

● Once the pipette has been used to place one reactant into the conical flask, fill the burette with the other reactant. Record initial volume.
● Add a few drops of indicator to the conical flask.
● Open the burette tap and allow the reactant to flow into the conical
flask, swirling it to mix the contents.
● Close the burette tap once the expected colour change occurs. Use a
white tile so the colour change is easy to identify.
● Record final burette volume.
● Repeat until you get concordant results, then calculate a mean titre.

Question 6

Why are acid-base indicators used?

Answer 6

To detect when a reaction reaches completion, usually by the presence of a colour change.

Question 7

What are concordant results?

Answer 7

Titres that are within 0.1 cm3 of each other.

Question 8

What are some common potential hazards?

Answer 8

bunsen burner
chemicals
glassware

Question 9

what are the potential risks

Answer 9

burns
irritants
glass breaking and cutting you

Question 10

give some controls

Answer 10

Keep flame away from flammable chemicals and away from the edge of the desk.

Handle chemicals with care and while wearing gloves. Wear eye protection. Keep away from the edge of the desk and from an open flame. Don’t ingest.

Handle glass with care. Keep away from edge of the desk.