Chemistry Unit

Which of the following is NOT typically considered evidence of a chemical change?

Which process demonstrates a physical change in water?

What fundamental principle is demonstrated when the total mass of reactants equals the total mass of products in a chemical reaction?

In a balanced chemical equation, what is permissible to change, and what must remain constant?

Consider the reaction: $6CO_2 + 6H_2O \rightarrow C_6H_{12}O_6 + 6O_2 $. What role does $H_2O$ play in this reaction?

When balancing the equation $Fe + Cl_2 \rightarrow FeCl_3$, what coefficient is placed before $Fe$ to correctly balance the equation?

A chemist observes that mixing two clear solutions results in the immediate formation of a cloudy solid. This observation is most indicative of:

A student performs an experiment where they burn a wooden log in a controlled environment. After the log is completely burned, they collect all the remaining ash and gases. When comparing the mass before and after the experiment, which statement is most accurate concerning observations based on the Law of Conservation of Mass?

Which of the following is a physical change?

What is the definition of a chemical equation?

In a chemical equation, what distinguishes reactants from products?

According to the law of conservation of mass, what must be true of a chemical reaction?

Why is it unacceptable to change subscripts when balancing a chemical equation?

Which of the following observations most likely indicates a chemical reaction has occurred?

In the balanced chemical equation for the reaction of methane ($CH_4$) with oxygen ($O_2$), what is the coefficient in front of oxygen?

Consider the (unbalanced) reaction: $Al + HCl \rightarrow AlCl_3 + H_2$. Once balanced, what is the coefficient in front of $HCl$?

A student mixes two clear solutions, and observes that the mixture becomes cloudy, with solid particles settling to the bottom of the container. Which of the following best describes this observation?

A chemist attempts to react two substances, but no reaction occurs. Upon closer inspection, they realize a crucial element is missing from the reactant mixture, one that is present in the products. This violates which fundamental chemical principle?

In the balanced equation $2FeBr_3 + 3H_2SO_4 \rightarrow Fe_2(SO_4)_3 + 6HBr$, what is the ratio of iron(III) bromide to sulfuric acid?

For the equation $P_4 + 5O_2 \rightarrow P_4O_{10}$, what is the coefficient of the oxygen reactant?

What type of reaction is exemplified by the general equation: Hydrocarbon + Oxygen → Water + Carbon Dioxide + Energy?

Which type of reaction involves simpler substances combining to form a more complex compound?

The breakdown of $H_2CO_3$ into $H_2O$ and $CO_2$ is an example of which type of reaction?

What is the coefficient for $O_2$ when the following equation is properly balanced? $C_3H_8 + O_2 \rightarrow CO_2 + H_2O$

What term describes the minimum energy required to initiate a chemical reaction?

In a double replacement reaction, what type of chemical species switch places?

Which of the following is a balanced equation?

Which of the following is characteristic of an exothermic reaction?

What is the process by which living organisms obtain energy, similar to a combustion reaction?

Which type of reaction involves one substance breaking down into two or more substances?

What is the primary characteristic of a combustion reaction?

How does a catalyst affect a chemical reaction?

Which of the following best describes a synthesis reaction?

In an endothermic reaction, is energy absorbed or released, and does the temperature increase or decrease?

What role does a catalyst play in a chemical reaction?

Which of the following is NOT a factor that typically increases the rate of a chemical reaction?

Identify the type of reaction represented by: $Mg + 2HCl \rightarrow MgCl_2 + H_2$

Which of the following is an example of a balanced decomposition reaction?

In the balanced equation $2AlBr_3 + 3K_2SO_4 \rightarrow 6KBr + Al_2(SO_4)_3$, how many moles of $KBr$ are produced if you start with 2 moles of $AlBr_3$?

If a substance has a pH of 14, such as Drano, what can be said about it?

Which reaction type is represented by: $2HCl + CaCO_3 \rightarrow CaCl_2 + H_2O + CO_2$?

In the balanced equation $2HgO \rightarrow 2Hg + O_2$, if 216.6 grams of mercury (Hg) are produced from the decomposition of mercury oxide (HgO), and knowing that the molar mass of Hg is approximately 200.59 g/mol, how many moles of $O_2$ are also produced, assuming the reaction goes to completion and the molar mass of $O_2$ is approximately 32 g/mol?

In an endothermic reaction, what is the relationship between the energy required to break bonds in the reactants and the energy released when products form?

Given the unbalanced equation $FeCl_3 + NaOH \rightarrow Fe(OH)_3 + NaCl$, what is the coefficient of $NaOH$ when the equation is balanced?

Consider a scenario where an aqueous solution of hydrochloric acid (HCl) at a concentration of 1.0 M is mixed with an equal volume of aqueous ammonia ($NH_3$) at a concentration of 1.0 M in a calorimeter. Given that the neutralization reaction releases heat, and assuming that both solutions were initially at 25°C, what would be the most likely final temperature reading of the mixture inside the calorimeter, and what can be inferred about the reaction's enthalpy change ($\Delta H$)?

Consider the reaction: $C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O$. What is the common name for this specific type of combustion reaction?

Which of these processes is an example of an endothermic reaction?

What is activation energy?

Which of the equations correctly represents the balanced form of: $K + MgBr_2 \rightarrow KBr + Mg$?

Given the balanced equation: $1 S_8 + 12 O_2 \rightarrow 8 SO_3$, if the reaction vessel initially contains 8 moles of $S_8$ and 96 moles of $O_2$, assuming complete conversion according to the balanced chemical equation, how many moles of the limiting reactant will remain after the reaction goes to completion?

How does increasing the surface area of a solid reactant typically affect the rate of a chemical reaction?

A chemist mixes two clear solutions, $A$ and $B$, and observes the formation of a yellow precipitate. Conceptualizing this scenario within the context of reaction types, select the reaction which would most probably correlate with the observed chemical process, assuming solubility rules are being followed correctly.

Why does increasing the temperature generally increase the rate of a chemical reaction?

How does a catalyst increase the rate of a chemical reaction?

What is the primary function of an enzyme in a living cell?

What effect do inhibitors have on chemical reactions?

Cellular respiration is the reverse process of photosynthesis. Photosynthesis is endothermic, which means cellular respiration is:

Which actions would cause an iron bar to rust more quickly?

Why does refrigerating food extend its life?

A catalyst does not increase the amount of product formed in a reaction because:

How does the chewing of food relate to the rate of a chemical reaction during digestion?

Predict the effect on reaction rate if a chemist tripled the concentration of a gaseous reactant and simultaneously decreased the volume of the reaction vessel to one-third of its original size, assuming temperature remains constant.

Signs of Chemical Change?

Chemical Change

Physical Change

Law of Conservation of Mass

Balancing Chemical Equations

Coefficient

Reactant

Product

Chemical Reaction

Chemical Equation

Signs of a Chemical Reaction

Bonds in Chemical Reaction

Combustion Reaction

Synthesis Reaction

Decomposition Reaction

Activation Energy

Exothermic Reaction

Enzymes

Catalyst

Endothermic Reaction

pH Scale

Acid

Base

Photosynthesis

Single Replacement Reaction

Double Replacement Reaction

Reaction Patterns

Inhibitor

Chemical Energy

Cellular respiration

Reaction Rate

Surface Area

Temperature (Reaction Rate)

Concentration (Reaction Rate)

Exo vs. Endo

Opposite of Photosynthesis?

Refrigeration

Sun's Energy

Chewing Food