Identifying Reactions/Predicting Products
What kind of reaction is being displayed here? How do you know?
Na + Cl2 -->
Synthesis (E + E --> C)
Balance the following reaction: Li + Br2 → LiBr
2Li + Br2 → 2LiBr
Determine whether the following molecule is soluble or insoluble: MgCO3
Insoluble
Draw the beaker diagram that results when salt (sodium chloride) is dissolved in water.
Beaker diagram should contain H2O (l) and Na+ and Cl- ions.
Name one indicator that a chemical change is occurring.
New odor, unexpected color change, production of heat AND light, formation of a precipitate, production of a gas.
Which reaction type(s) start(s) with a single compound and an element as a reactant?
Single replacement and Combustion
Balance the following equation: CaCl2 + Na3PO4 → Ca3(PO4)2 + NaCl
3CaCl2 + 2Na3PO4 → Ca3(PO4)2 + 6NaCl
Determine whether the following molecule is soluble or insoluble: CaS
Soluble
Solid Mg2(PO4)3 is placed in water and stirred. Draw the beaker diagram that results.
This molecule is insoluble so it should just be written as Mg2(PO4)3 (s) in the beaker.
Name one indicator that a physical change is occurring.
A solid dissolving, natural/expected phase change, change in size/shape of matter
Predict the products of the following reaction:
CH4 + O2 →
CO2 + H2O
Balance the following equation: Fe2O3(s) + C(s) → Fe(s) + CO2(g)
2Fe2O3(s) + 3C(s) → 4Fe(s) + 3CO2(g)
Identify whether the following molecule is soluble or insoluble: lead (II) chloride
Insoluble.
Solid lithium chromate is placed in water and stirred. Draw the beaker diagram that results.
This molecule is soluble so the beaker diagram should contain two Li+ ions and one CrO42- ion.
Is calcium chloride dissolving in water a physical or a chemical change? How do you know?
Physical change because dissolving is a physical change...you can get the original substances back if you wanted to.
Is the following reaction written correctly? If not, why? Fe2O3 → Fe + O
No, it should be Fe2O3 --> Fe + O2 because O is one of the HOFBrINCl elements
C2H6 undergoes a combustion reaction. Write the balanced equation for this reaction.
2C2H6 + 7O2 --> 4CO2 + 6H2O
Give me an example of a soluble molecule that contains something that's typically insoluble.
Multiple correct answers! The answer should contain an anion that is generally insoluble, but that is paired with a cation that is an exception.
Draw the beaker diagram for the products that result from the following reaction:
MgCl2 (aq) + Na2SO4 (aq) -->
Mg2+, SO42-, Na+, Na+, Cl-, Cl-
In the lab, I translucent yellow aqueous solution with a translucent blue aqueous solution. The result is a translucent green solution. Is this a chemical reaction, a physical reaction, or no reaction? Explain.
No reaction. Yellow and blue is expected to make green. Since no other product formed (which you can tell because the solution stayed translucent and you couldn't see any solid form), nothing happened.
Below are some reactants in a chemical equation. Write a sentence to represent the entire reaction.
Hg2O + Na -->
Mercury (I) oxide reacts with sodium to create sodium oxide and mercury.
Balance the following equation: Be2C + H2O --> Be(OH)2 + CH4
Be2C + 4H2O --> 2Be(OH)2 + CH4
Does the reaction of FeCl3 (aq) and NaOH (aq) produce a precipitate? If not, why not? If so, what is the precipitate?
Yes. Fe(OH)3 is the precipitate.
Write a balanced reaction with states for the following reaction and draw both the reactant and product beaker diagrams:
Solutions of copper (II) sulfate and sodium hydroxide react in a double replacement reaction.
CuSO4 (aq) + 2NaOH (aq) -> Cu(OH)2 (s) + Na2SO4 (aq)
Product beaker: Cu(OH)2 (s) and Na+ Na+ SO42-
What is a precipitate? What type of reaction(s) can produce precipitates? What is a sign that a precipitate has formed from a reaction?
A precipitate is formed when two aqueous solutions are mixed together and a solid results. They are formed in double replacement reactions. You can tell that a precipitate has formed when the solution becomes opaque.