Unknown Masses
3.1g + 8.2g = ? g
What is 11.3g?
2CO + O2 --> 2CO3
What is unbalanced?
Mg + O2 --> MgO
The product is missing 1 atom of O.
2HgO --> O2 + 2Hg
60.0g 4.2g ? g
What is 55.8g?
What is the result of ALL chemical reactions?
a new substance is formed
5.1g + 3.8g = ? g
What is 8.9g?
3H2 + 2O2 --> 3H2O
What is not balanced?
Sr + CO3 --> Sr2CO3
The product has 1 extra atom of Sr.
4Al + 3O2 --> 2Al2O3
27g 32g ? g
What is 59g?
50 grams of magnesium reacts with oxygen. How many grams of magnesium will be present after the reaction occurs?
What is 50 grams?
3.0g + ? g = 9.5g
What is 6.5g?
4Fe + 3O2 --> 2Fe2O3
What is balanced?
2NH3 + O2 --> NO + 3H2O
The product is missing 1 atom of N.
C + O2 --> CO2
0.24g 0.64g ?g
What is 0.88g?
The chemical formula for a substance is
KCl
This substance can best be described as
A. an atom of potassium chloride
B. the compound potassium chloride
C. the element potassium chloride
What is B. the compound potassium chloride?
? g + 18.3g = 23.8g
What is 5.5g?
2N2 + 3H2 --> 2NH3
What is not balanced?
6CO2 + 6H2O --> C6H12O + 6O2
The product is missing 6 atoms of O.
2K + Br2 --> 2KBr
39.1g ? g 119.0g
What is 79.9g?
Which action is the best example of a chemial change?
A. creating new substances by hammering an iron nail into a piece of wood
B. creating new substances by cutting copper wire into smaller pieces
C. creating a new substance by burning small twigs to set a log on fire
What is C. creating a new substance by burning small twigs to set a log on fire?
6.7g + ? g = 9.4g
What is 2.7g?
2Na + 2H2O --> 2NaOH + H2
What is balanced?
CaCO3 --> CO2 + CaO
10g 4.4g 6.6g
The product has 1 gram too many.
2Na + Cl2 --> 2NaCl
23g ? g 71g
What is 48g?
A chemical equation is shown below.
4Fe + 3O2 --> 2Fe2O3
The mass of 2Fe2O3 produced must be equal to
A. the total mass of 4Fe and 3O2
B. twice the total mass of 4Fe and 3O2
What is A. the total mass of 4Fe and 3O2?