science ch.1.6 Flashcards
(22 cards)
how do we transfer a large amount of solution?
pour it out directly
How do we transfer a small amount of solution?why?
use a dropper , Bc a dropper help us control the amount of solution to transfer more easily
Why shouldn’t we hold a dropper upside-down?
The solution will go into the rubber bulb and it may be contaminated by any substance left there
How should we mix solutions in a test tube well
tap the bottom of the test tube with the index finger
who invented Bunsen burner?
Robert Bunsen
What’s the use of the collar of the Bunsen burner ?
To control the size of the air hole
What is the use of air hole of a Bunsen burner
to let air in
What is the use of chimney of a Bunsen burner
to direct air and gas to the flame
what is the use of rubber tubing of a Bunsen burner
to connect the Bunsen burner to the gas tap
Should we close the air hole of the Bunsen burner after placing gas lighter above the top of chimney? yes or no?
no
What is the flame called when the air hole is closed?
Luminous flame
What is the flame called when the air hole is open
Non-luminous flame
Two ex of the Luminous flame
the shape is irregular , its quiet
two ex of Non-luminous flame
The shape is regular , its noisy
which flame has an innercone
Non-luminous
which part of the Non-luminous flame is the hottest and where is the coolest?
the tip of the inner cone is hottest , The bottom of the inner cone isn’t v hot
three safety precaution examples
!. The room should be well-ventilated 2. wear safety goggles 3. Close the air hole before lighting the Bunsen burner 4. Dont fully open air hole after lighting Bunsen burner
When doest strike back happen?
When the air hole is fully open
What does a strike back look like? two features
A flame inside air hole , a hissing sound
what to do when strike back happens?
turn off the gas tap immediately and inform the teacher
Dont touch the chimney and collar
v hot
which flame do we use for heating , why?
Non-luminous flame bc its hotter
