Physical and Chemical Changes
Chemical Equations
Law of Conservation of Mass
Balanced or Unbalanced
Miscellaneous
100
When you add water to a mixture of citric acid and baking soda, carbon dioxide is produced.
Is this a chemical or a physical reaction?
What is chemical reaction
100
Which part of the chemical equation – the reactants or the products – is represented on the left side?
KCl + O2 -> KClO3
reactants
100
When 30 grams of ice melts, how many grams of water should there be according to the Law of Conservation of Mass?
What is 30
100
TRIPLE POINTS
Balance this equation:
P + O2 -> P2O5
4P + 5O2 -> 2P2O5
100
Name this compound:
LiBr
Lithium Bromide
200
Ice melts into liquid. Is this a chemical or a physical change?
What is physical change
200
The equation below represents iron and oxygen forming rust. Which are the reactants and which are the products? 2Fe + O2 -> 2FeO
What is reactants: 2Fe+O2 Products: 2FeO
200
500 g of wood and oxygen burns. When you find the mass of the ashes, it is only 350 g.
What happened to the other 150 g of matter?
What is it was released as a smoke
200
Is the equation below balanced or unbalanced?
S8 + O2 -> SO3
unbalanced
200
Draw the dot structure for this molecule:
NH3
300
List three clues that a chemical reaction has taken place.
What is a new color forms, a new substance forms, change in odor, fizzing/foaming, heat or light given off
300
What does a subscript tell you in a chemical equation?
What is tells you how many atoms of a certain element in the molecule.
300
TRIPLE POINTS
36 grams of water has this many grams of hydrogen in it.
4 grams of Hydrogen
300
Is the equation below balanced or unbalanced?
K + MgBr2 -> 2KBr + Mg
unbalanced
300
DOUBLE POINTS
Predict the products if these react in a double-replacement reaction.
BCl3 + F2 -->
BF3 + Cl2
400
Is lemonade powder dissolving into water a chemical or a physical change?
What is physical change
400
What does a coefficient tell you in a chemical equation?
What is the number of molecules present in the reaction
400
Someone goes for a jog and subsequently lost 2.5 pounds. Where might that missing mass have gone?
Sweat and/or breath
400
Is the equation below balanced or unbalanced?
2H2O + O2 -> 2H2O2
balanced
400
An endothermic reaction would feel _____ if you touched the container it took place in.
COLD
500
Explain the difference between a physical and chemical change.
What is a chemical change occurs when a new substance is formed and a physical change is when matter changes form, but a new substance is not formed
500
C3H8 + 5O2 -> 3CO2 + 4H2O Which elements are in the above reaction? How many atoms of each element are on the reactants side? How many atoms of each element are on the products side?
What is Carbon, Hydrogen, and Oxygen. Reactant side: C-3 H-8 O-10 Product side: C-3 H-8 O-7
500
When iron rusts, its safe to say the new substance has a mass that is (greater than/equal to/less than) the original iron.
greater than
500
Is the equation below balanced or unbalanced?
H2SO4 + NaNO2 -> HNO2 + Na2SO4
What is unbalanced
500
In the chemical reaction of combustion, is heat a reactant or product?
Product