solution prep and dilution

Question 1

volumetric flask

Answer 1

pear-shaped glass that has a graduation mark which tells the exact volume at a specific temperature. precision is +/- 0.1 ml

Question 2

how to prep an aq solution using volumetric flask

Answer 2

1) place mass of solute in beaker. dissolve water to remove all the solute.
2) take a volumetric flask and add a small quantity of distilled water. rinse out the solute beaker until it fills the flask
3) transfer the solution from the beaker using a funnel
4) rinse the funnel and empty into the flask
5) view the neck of the flask straight from the side so the graduation mark looks like a line, not an ellipse. add water to the bottom of the meniscus touches the graduation mark.

Question 3

Standard solution

Answer 3

a solution with a known concentration.

Question 4

Pipette

Answer 4

glassware used to transport an accurately 
measured volume of a liquid.

Question 5

steps for making a solution

Answer 5

• measure out the mass of solute
• add as little water as possible to completely dissolve the solute
• transfer the solution from the beaker to the volumetric flask using a funnel
• rinse the beaker with disltilled water and pour the remaining into the volumetric flask to make sure all solute has transferred
• using a beaker, add distilled water to th volumetric flask until the meniscus is at the graduation mark

Question 6

stock solution

Answer 6

usually a concentrated solution that is diluted before it is used. has a known concentration

Question 7

using a volumetric pipette to measure the volume of a stock solution for dilution

Answer 7

• make sure that outside of the pipette, especially the tip is dry
• squeeze the pipette bulb and the place it over the top of the pipette. If using a pipette pump, place it over the tope of the pipette
• rinse the piptte as follows. Place the tip of the pipette below the surface of the stock solution. Release the bulb carefully to draw up some liquid until the pipette is about half full. Remove the pipette bulb, invert the pipette and drain the liquid into a beaker for waste. Repeat this a few times
• fill the pipette with stock solution so that the level is past the graduation mark but do tnot allow the stock solution into the pipette bulb
• remove the pipette bulb and quickly seal the top with your finger
• remove the tip of the pipette from the solutions. Lift your finger slowly and let stock solution drain out slowly until the meniscus reaches the graduation mark wipe the tip of the pipette with some towel
• move the pipette to the container into which you want to transfer the stock solution. Touch the tip of the pipette against the inside of the container and release our finger allowing the liquid to drain. A small volume will remain inside the pipette, it has been calibrated to allow for this volume of liquid. Do not force this liquid from the pipette

Question 8

standard solution

Answer 8

can be made from a solid solute by using a volumetric flask

Question 9

stock solutions

Answer 9

can be used to produce more dilute solutions