Chemical Reactions and Equations Assessment Study Guide Flashcards
What is an empirical formula?
An empirical formula is the simplest form of whole number. For example SO2 empirical formula would be SO
What is a molecular formula?
A molecular formula tells us how many of each type of atom are present in a molecule. For example the molecular formula of water is H2O this shows that there is one hydrogen and two oxygen atoms
What are diatomic elements?
Diatomic elements are molecules that only have two atoms.
Which elements are diatomic?
The seven diatomic elements are hydrogen, nitrogen,oxygen,Fluorine,chlorine,bromine,and iodine.
Turn the following molecular formulas into empirical formulas:
a. C6H12O6
b. C4H10
c. C2H4N2
a. C6H12O6 (CHO)
b. C4H10 (CH)
c. C2H4N2 (CHN)
What is the law of conservation of matter? What needs to be the same amount on both sides of the chemical equation?
The law of conservation of matter starts that in chemical reactions the total mass of the products must equal the total mass of the reactants.
What are reactants and what are products? How can you tell whether a substance is a reactant or a product?
The Substances that go in a chemical reaction are called reactants and the products are the substances produced at the end of a chemical reaction.
Calculate the mass of 0.50 moles Mg3(PO4)2.
131.35
How many moles are in 22.5 grams of Al2O3?
0.22
Determine the percent composition of each element in Na2SO4.
Na-32.3%
S-22.6%
O-45.1%
A compound is 15.8% carbon and 82.4% sulfur. What is the empirical formula of the molecule?
CS2
A 15.67 g sample of a hydrate of magnesium carbonate was heated, without decomposing the carbonate, to drive off the water. The mass was reduced to 7.58 g. What is the percentage of water in the hydrate?
51.6
Balance the following chemical equations:
____8CH2O + _____4O2 → _____8CO2 + _____8H2O
____CH2O + _____O2 → _____CO2 + _____H2O
_____2MgO → _____2Mg + _____ O2
_____MgO → _____Mg + _____ O2
_____ C3H8 + ____4O2 → _____4CO2 + _____8H2O
_____ C3H8 + ____O2 → _____CO2 + _____H2O
_____ CaCl2 + _____ KOH → _____ KCl + _____ Ca(OH)2
_____ CaCl2 + _____ KOH → _____ KCl + _____ Ca(OH)2
____4Al + _____6H2S → _____2Al2S3 + ___6H2
____Al + _____H2S → _____Al2S3 + ___H2
_____4NaCl + ____2Fe(SO4) → _____2Na2SO4 + ____2 FeCl2
_____NaCl + ____Fe(SO4) → _____Na2SO4 + ____FeCl2
_____ S8 + _____12O2 → _____8SO3
_____ S8 + _____O2 → _____SO3
What are the key reactants and products of combustion?
Hydrocarbon and oxygen are the reactants and the products are h20 and carbon dioxide
What are the products of KI + Pb(NO3)2, a double displacement reaction?
KI + Pb(NO3)2->2kNO3+PbI2
What are the products of Zn(II) + HCl, a single displacement reaction?
Zn(II) + HCl -> ZnCl2+H2
