Ch. 1.6 Flashcards
What are the three basic practical skills?
Transferring solutions, mixing solutions and heating.
How do we transfer a large amount of solution?
Pouring it out directly.
How do we transfer a small amount of solution?
Using a dropper.
What is an advantage of using a dropper?
It helps us control the amount of solution to transfer more easily.
How to use a dropper
- Gently squeeze the ___________ _______ of a dropper and don’t release it.
- Lower the _______ of the dropper into the solution.
- Release the bulb to ________ some solution.
- Remove any ____________ droplets from the tip of the dropper.
- Place the dropper at ________________ of an empty test tube.
- Gently squeeze the bulb to add the solution drop by drop to the empty test tube.
Rubber bulb, tip, draw, excess, the mouth
Why shouldn’t we hold the dropper upside down?
The solution will go into the rubber bulb and it may be contaminated by any substance left there.
We can use a dropper to transfer ___ _________ __________ of solution in the laboratory.
A small amount
Four ways to mix a solution: 1. 2. 3. 4.
- Use a glass rod to stir the mixed solution
- Gently shake the test tube
- Tap the bottom of the test tub with the index finger
- Stopper the test tube and shake well
Four types of solutions: 1. 2. 3. 4.
- Clear solution
- Cloudy solution
- Solids formed
- Bubbles formed
What do we use for heating in the laboratory?
A Bunsen burner.
What is the use of the chimney in a Bunsen burner?
To direct air and gas to the flame.
What is the use of an air hole in a Bunsen burner?
To let air in.
What is the use of the collar in a Bunsen burner?
To control the size of the air hole.
What is the use of the base in a Bunsen burner?
To hold the chimney upright.
What is the use of the rubber tubing in a Bunsen burner?
To connect the Bunsen burner to the gas tap.
How to light a Bunsen burner
- Put the Bunsen burner on a _________________
- Connect the rubber tubing to the ____________, make sure the connection is right
- _________ the air hole
- Place a ______________ just above the top of the chimney
- Press the button of the _____________ and turn on the gas tap
- ____________ the air hole slowly
Heat-proof mat, gas tap, close, gas lighter X2, open
Sometimes, a ________________may occur if the air hole is fully ________ when ____________ a Bunsen burner.
Strike back, open, lighting
What does a strike back look like?
Hint: there are two points
Green flame
Hissing sound
What are the characteristics of a flame with the air hole of the Bunsen burner closed? Name: Sound: Colour: Shape: Temperature
Name: luminous flame Sound: quiet Colour: yellow Shape: irregular Temperature: lower temperature
What are the characteristics of a flame with the air hole of the Bunsen burner opened? Name: Sound: Colour: Shape: Temperature:
Name: non-luminous flame Sound: noisy Colours: blue Shape: regular Temperature: higher temperature
