w7 reagent prep

Question 1

water purity importance

Answer 1

water is most common solvent in lab. quality of water will affect the quality of reagents being prepared

Question 2

impurities found in water

Answer 2

metals, ions, gases, bacteria, pH of water also looked at

Question 3

type 1 water

Answer 3

• best quality minimal impurities
• used for chemical testing, reagent prep and controls
• cannot be stored, it will absorb carbon dioxide

Question 4

type 2 water

Answer 4

• good quality used for preparing solutions

- may be stored in closed bottles for short periods of time

Question 5

type 3 water

Answer 5

• lowest quality used for purposes not requiring accuracy, like washing
• used to produce type 1 and type 2 water

Question 6

what is purity of water determined by

Answer 6

amount of electrical resistance and it is measured in mega ohms *pure water has high electrical resistance. - less conductivity due to lack of dissolved particles

Question 7

steps in water purification system 5

Answer 7

distillation
deionization
reverse osmosis
carbon absorption
filtration

Question 8

analytical grade

Answer 8

also known as reagent grade highest purity and used to prepare most reagents in lab-max amount of impurities listed on label. -make Nacl in lab

Question 9

commercial grade chemicals

Answer 9

are generally not used in lab, have a high degree of impurities