1.
Lets say you mix a Solution A, which is already yellow, and a solution B, which is already yellow as well. After you mix them, the solution is still yellow. What can you conclude?
Correct Answer
B. You can't conclude that a chemical reaction has occurred because there was no color change
Explanation
The fact that the solution remains yellow after mixing two yellow solutions indicates that there was no color change. Color change is often an indication of a chemical reaction taking place. However, in this case, since there is no color change, it cannot be concluded that a chemical reaction has occurred. The absence of a color change suggests that the two solutions are compatible and do not react with each other.
2.
Magnesium + Water --> Magnesium Hydroxide and Hydrogen Gas. What is a product (P) and what is a reactant (R)?
Correct Answer
A. P= Magnesium Hydroxide R= Water
Explanation
In this reaction, magnesium reacts with water to form magnesium hydroxide and hydrogen gas. The product (P) is magnesium hydroxide because it is formed as a result of the reaction. The reactant (R) is water because it is the substance that reacts with magnesium to produce the product.
3.
How can you tell if a chemical equation is balanced?
Correct Answer
D. The number of atoms on the product side and reactant side are the same
Explanation
If the number of atoms on the product side and reactant side are the same, it indicates that the chemical equation is balanced. Balancing a chemical equation involves ensuring that the number of atoms of each element is equal on both sides of the equation. This is important because it reflects the law of conservation of mass, which states that matter cannot be created or destroyed in a chemical reaction. By balancing the equation, it shows that the same number of atoms are present before and after the reaction, maintaining the overall mass of the system.
4.
What is in a correctly written chemical equation?
Correct Answer
D. All of the above
Explanation
A correctly written chemical equation includes the states of matter of the reactants and products, the correct chemical formulas of the reactants and products, and the amounts of reactants and products. This means that all of these components are necessary for a chemical equation to be considered correct.
5.
What are coefficients used for?
Correct Answer
C. To balance the equation
Explanation
Coefficients are used to balance an equation. In a chemical equation, coefficients represent the number of molecules or atoms involved in the reaction. Balancing the equation ensures that the number of atoms on both sides of the equation is equal, satisfying the law of conservation of mass. By adjusting the coefficients, the equation can be balanced, meaning that the same number of atoms of each element is present on both sides of the equation. This is important to accurately represent the reaction and its stoichiometry.
6.
The formation of a gaseous product is indicated by the symbol:
Correct Answer
B. (g)
Explanation
The symbol (g) is used to indicate the formation of a gaseous product. It signifies that the substance is in the gas phase. This symbol is commonly used in chemical equations to indicate the state of the product. In contrast, (s) is used for solids, (vap) is used for vapors, and (l) is used for liquids.
7.
2NaNO3 What is the coefficient, and what is the subscript?
Correct Answer
D. 2, 3
Explanation
The correct answer is 2, 3. In the chemical formula 2NaNO3, the coefficient is 2, indicating that there are two molecules of NaNO3. The subscript is 3, indicating that there are three atoms of oxygen in each molecule of NaNO3.
8.
How many molecules are represented by this: 4H2O
Correct Answer
A. 4
Explanation
The chemical formula 4H2O represents four molecules of water. Each molecule of water consists of two hydrogen atoms bonded to one oxygen atom. Therefore, multiplying the number of water molecules (H2O) by 4 gives us a total of four water molecules.
9.
How many molecules are on the reactants side in this: Nh4NO2 --> N2 + 2H2O
Correct Answer
B. 1
Explanation
In the given chemical equation, Nh4NO2 decomposes to form N2 and 2H2O. The reactant side consists of only one molecule, which is Nh4NO2. Therefore, the correct answer is 1.
10.
How many molecules are on the products side in this: Nh4NO2 --> N2 + 2H2O
Correct Answer
D. 3
Explanation
In the given chemical equation, Nh4NO2 decomposes to form N2 and 2H2O. This means that one molecule of Nh4NO2 produces one molecule of N2 and two molecules of H2O. Therefore, there are a total of three molecules on the products side of the equation.
11.
Is this equation balanced?2Fe+ O2 --> Fe2O3
Correct Answer
C. No
Explanation
The equation is not balanced because the number of atoms of each element is not equal on both sides of the equation. On the left side, there are 2 iron (Fe) atoms and 2 oxygen (O) atoms, while on the right side, there are 2 iron (Fe) atoms and 3 oxygen (O) atoms. To balance the equation, we need to adjust the coefficients in front of each compound so that the number of atoms of each element is the same on both sides.
12.
Is this equation balanced?4H2+ 2O2 --> 2H2O
Correct Answer
D. No
Explanation
The equation is not balanced because the number of hydrogen atoms on both sides of the equation is not equal. On the left side, there are 4 hydrogen atoms, while on the right side, there are only 2 hydrogen atoms. In order for the equation to be balanced, the number of atoms of each element must be the same on both sides.
13.
What type of reaction forms one product from two or more compounds?
Correct Answer
C. A+X-> AX
Explanation
The correct answer is A+X-> AX. This reaction represents a synthesis reaction, where two or more compounds combine to form a single product. In this case, compound A reacts with compound X to form compound AX.
14.
What is the general formula for a double displacement reaction?
Correct Answer
B. AX+BY-> AY + BX
Explanation
The general formula for a double displacement reaction is AX + BY -> AY + BX. In this type of reaction, the cations of two different compounds switch places with each other, resulting in the formation of two new compounds. The reactants AX and BY combine to form the products AY and BX. This type of reaction is also known as a metathesis reaction or a precipitation reaction, as it often involves the formation of a precipitate when two aqueous solutions are mixed together.
15.
In what type of reaction may a precipitate form, and there are two products?
Correct Answer
D. Double Displacement
Explanation
In a double displacement reaction, two compounds react and exchange ions, resulting in the formation of two new compounds. This type of reaction often occurs in aqueous solutions and can result in the formation of a precipitate, which is an insoluble solid that forms when two solutions are mixed. Therefore, in a double displacement reaction, a precipitate may form, and there are two products.
16.
In What movie are potatoes grown from an plant chemist using the combustion of hydrogen and oxygen?
Correct Answer
C. The Martian
Explanation
In the movie "The Martian," potatoes are grown by a plant chemist using the combustion of hydrogen and oxygen. This means that the character in the movie uses a chemical reaction involving hydrogen and oxygen to create the necessary conditions for growing potatoes.
17.
When we burn gasoline, or propane what type of chemical reaction is occuring?
Correct Answer
B. Combustion
Explanation
When we burn gasoline or propane, a chemical reaction called combustion occurs. Combustion is a type of exothermic reaction where a fuel combines with oxygen in the presence of heat to produce carbon dioxide, water, and heat energy. In this case, the gasoline or propane acts as the fuel, and when it reacts with oxygen, it releases energy in the form of heat and light, resulting in fire. Therefore, combustion is the correct answer for the given question.
18.
What is the only type of reaction that can occur if you have these reactants?2HCl + Cr -->
Correct Answer
D. Single Replacement
Explanation
The given reactants 2HCl + Cr indicate a single replacement reaction. In a single replacement reaction, one element replaces another element in a compound. Here, the chlorine in HCl is replaced by the chromium (Cr) atom. Therefore, the correct answer is Single Replacement.
19.
If I have a compound X and it reacts to form compound Y and Z, what type of reaction is this?
Correct Answer
A. Decomposition
Explanation
The given reaction describes the compound X breaking down into compounds Y and Z. This is characteristic of a decomposition reaction, where a single compound breaks down into two or more simpler substances.
20.
In a single displacement reaction, how can you tell if the reaction will occur?
Correct Answer
A. Consult you activity series, if the single element is above the first element in the other compound , the reaction will occur
Explanation
The correct answer is to consult the activity series and check if the single element is above the first element in the other compound. This is because the activity series is a list of metals and nonmetals arranged in order of their reactivity. If the single element is above the first element in the other compound, it means that it is more reactive and will displace the first element to form a new compound. Therefore, the reaction will occur.
21.
What does the symbol (aq) represent?
Correct Answer
C. Aqueous
Explanation
The symbol (aq) represents the term "aqueous." Aqueous refers to a solution in which a substance is dissolved in water. It indicates that the substance is in a liquid state and is dissolved in water.
22.
If element X reacts with Zinc Chloride, what can be said?
Correct Answer
B. Zinc is lower on the activity series than X
Explanation
This answer suggests that Zinc is lower on the activity series than element X. The activity series is a list of metals arranged in order of their reactivity, with the most reactive metals at the top. If Zinc is lower on the activity series than X, it means that X is more reactive than Zinc and is likely to displace Zinc in a chemical reaction.
23.
A + BX --> AX + B is what type of reaction?
Correct Answer
D. Single displacement
Explanation
In a single displacement reaction, one element is replaced by another element in a compound. In the given reaction, the element A is being replaced by the element B in the compound BX, resulting in the formation of compound AX and the release of element B. Therefore, the given reaction is a single displacement reaction.