Lab Safety
This piece of protection should be worn at all times during a lab to prevent damages in the eyes.
What are goggles?
A student wants to investigate whether the amount of sunlight affects plant growth. She uses the same type of plant, soil, and amount of water, but places the plants in different amounts of sunlight. What is the independent variable?
amount of sunlight
Name: Fe₂O₃
Iron(III) oxide
2Mg + O2 → 2MgO
synthesis
Always follow the directions of this person during a lab.
Who is your teacher?
A scientist wants to determine whether temperature affects the rate at which sugar dissolves in water.
Which setup would provide the most reliable results?
A. Use different amounts of sugar in hot and cold water.
B. Use the same amount of sugar and water but different temperatures.
C. Use different types of sugar at different temperatures.
B
formula for calcium nitrate
Ca(NO₃)₂
2 KClO3 → 2KCl + 3O2
decomposition
You should never do this in a lab, as chemicals could contaminate what you are enjoying.
What is eat or drink?
A scientist tests a new fertilizer on tomato plants. What group should be the control group?
Plants receiving no fertilizer
name for N₂O₅
Dinitrogen pentoxide
Zn + CuSO4 → ZnSO4 + Cu
single replacement
Do this when a chemical spills on you.
What is wash it off?
Why do scientists perform multiple trials in an experiment?
To increase reliability and reduce random errors
ammonium phosphate
(NH₄)₃PO₄
AgNO3 + NaCl → AgCl + NaNO3
double replacement
During a chemistry lab, four students are preparing to heat a liquid in a test tube.
B
A student investigates how the amount of water affects the growth of grass.
What is the dependent variable?
the height of grass
tin(IV) chloride
SnCl₄
CH4+ 2O2 → CO2+ 2H2O
combustion