4B3 Predicting Products Flashcards
Identify products of reaction types such as combustion, synthesis, decomposition, and neutralization.
List five types of chemical reactions.
- Combination
- Decomposition
- Single-Replacement
- Double-Replacement
- Combustion
These reaction types describe how reactants transform into products through rearrangement or energy changes.
True or False:
Combustion always produces water and carbon dioxide.
True
Combustion reactions involve a hydrocarbon reacting with oxygen to yield carbon dioxide, water and energy.
These products are consistent regardless of the specific hydrocarbon used in the reaction.
Which gas is produced during incomplete combustion?
Carbon monoxide
Incomplete combustion produces less energy and creates carbon monoxide instead of carbon dioxide.
How can you extinguish a small fire without a fire extinguisher?
By smothering it with a heavy cloth or blanket to cut off the oxygen supply.
Oxygen is essential for combustion; removing it extinguishes the fire.
Which steps are followed to balance a combustion equation?
- Write the skeleton equation.
- Balance carbon.
- Balance hydrogen.
- Balance oxygen.
A final check ensures the number of atoms on both sides of the equation is equal.
How is a decomposition reaction different from a combination reaction?
- Decomposition: It breaks down a single reactant into multiple products.
- Combination: It forms a single product from multiple reactants.
Decomposition is essentially the reverse of a combination reaction.
A combination reaction is also known as a synthesis reaction. Decomposition reactants always start with a single reactant.
List three indicators of a chemical change.
- Heat or light emission.
- Color change.
- Gas formation (bubbling).
These are observable signs that a chemical reaction has occurred.
What does the state symbol (aq) represent in a chemical reaction?
Aqueous, meaning the substance is dissolved in water.
State symbols (g, l, s, aq) indicate the physical state of substances in a chemical reaction.
True or False:
All synthesis reactions produce binary compounds.
False
Synthesis reactions can produce binary or ternary compounds depending on the reactants involved.
How does a metal carbonate decompose?
It breaks down into:
- A metal oxide
- Carbon dioxide gas (CO₂)
Example: CaCO₃→CaO+CO₂
List the products of the decomposition of potassium chlorate (KClO₃).
- Potassium chloride (KCl)
- Oxygen (O₂)
The decomposition of metal chlorates produces a metal chloride and oxygen.
Reaction: 2KClO₃→2KCl+3O₂
List the products of the decomposition of calcium hydroxide (CaOH₂).
- Calcium oxide (CaO)
- Water (H₂O)
Reaction: Ca(OH)₂→CaO+H₂O
Fill in the blank:
Carbon dioxide (CO₂) and water (H₂O) combine to form _______ ____ ?
Carbonic acid
(H₂CO₃)
This is an example of a synthesis reaction forming a ternary compound.
A ternary compound is a compound made up of three elements.
True or False:
Energy is usually required for decomposition reactions.
True
Energy input, such as heat, light, or electricity, is often necessary to break bonds in decomposition reactions.
How can you predict the product of a synthesis reaction?
By analyzing the reactants and their properties.
For example, combining a metal and a nonmetal typically forms an ionic compound.
True or False:
A complex compound can decompose into its individual elements.
False
A complex compound usually breaks into smaller compounds, not individual elements.
Example: ABC→AB+BC
What is a dehydration reaction?
A unimolecular reaction where the reactant loses two hydrogen atoms and an oxygen atom, forming water and a dehydrated version of the reactant.
Dehydration reactions involve one reactant and typically result in the formation of a double bond in organic compounds.
Fill in the blank:
In a dehydration reaction, one product is always ______.
water
The formation of water from two hydrogen atoms and one oxygen atom lost from the reactant is a hallmark of dehydration reactions.
Define:
hydrolysis
A chemical reaction where a water molecule is used to break bonds in a reactant, typically producing two products.
Hydrolysis means “to cut with water”.
Water acts as a reactant, providing a hydroxyl group and a hydrogen atom to break bonds in the reactant.
How does a dehydration reaction differ from hydrolysis?
- Dehydration: It produces water as a product.
- Hydrolysis: It uses water as a reactant to break bonds.
Dehydration typically results in two products, while hydrolysis often splits a molecule into two smaller ones.
List two products of the dehydration of ethanol.
- Ethylene
- Water
Ethanol loses a hydrogen and a hydroxyl group during dehydration to form ethylene and water.
Which compound is the dehydrated product of copper(II) sulfate pentahydrate (CuSO₄·5H₂O)?
Copper(II) sulfate (CuSO₄)
Heating copper(II) sulfate pentahydrate (CuSO₄·5H₂O) removes water molecules to form anhydrous CuSO₄.
The color change from blue (hydrated) to white (anhydrous) is a visible indicator of this reaction.
Define:
condensation reaction
A chemical reaction in which water is lost from one or more reactants.
Condensation reactions can involve multiple reactants, unlike unimolecular dehydration reactions.
Dehydration reactions are a subset of condensation reactions.
What are the reactants and products in the hydrolysis of sucrose?
- Reactants: Sucrose and water.
- Products: Glucose and fructose.
Hydrolysis breaks sucrose into its monomers by using a water molecule.
Fill in the blank:
Inorganic dehydration reactions often result in the removal of water from ________.
hydrates
Hydrates lose water to form anhydrous compounds, a process often driven by heat.
Define:
neutralization reaction
A reaction where acids and bases react to form salt and water.
Neutralization involves the reaction of acids donating protons and bases accepting them.
Hydrogen ions (H⁺) and hydroxyl ions (OH⁻) combine to form water.
What is the general equation for a neutralization reaction?
Acid + Base → Salt + Water
Neutralization is a form of displacement reaction.
Displacement reactions rearrange ions to form new compounds.
Which acid reacts with NaOH to form NaCl?
Hydrochloric acid
(HCl)
Reaction: HCl + NaOH → NaCl + H₂O
Define:
pH
A scale measuring the acidity or basicity of a solution.
pH ranges from 0 (acidic) to 14 (basic); pH = 7 is neutral.
How does the pH change when a strong acid reacts with a strong base?
It becomes neutral (pH = 7).
This reaction completely neutralizes the acid and base.
Which type of solution is produced when a weak acid reacts with a strong base?
A basic solution (pH > 7).
The strong base dominates the reaction, making the solution basic.
List two strong acids and two strong bases.
- Strong Acids: HCl, H₂SO₄
- Strong Bases: NaOH, KOH
Strong acids/bases dissociate completely in water forming ions.
Weak acids/bases dissociate partially in water due to their strong attachment to protons.
Fill in the blank:
Bee stings are _______ and can be treated with baking soda.
acidic
Baking soda, a base, neutralizes the acid in bee stings.
What happens when HBr reacts with KOH?
Water (H₂O) and potassium bromide (KBr) are formed.
Reaction: HBr + KOH → KBr + H₂O
Fill in the blank:
Toothpaste contains ______ compounds to neutralize acidic mouth bacteria.
basic
Basic compounds in toothpaste help maintain oral pH balance.
What is titration used for in chemistry?
To determine the concentration of a compound.
An example would be an acid-base titration, which uses a known acid or base to neutralize the unknown solution.
Define:
precipitation reaction
A reaction where two soluble salts react to form an insoluble product.
These reactions involve the exchange of ions between compounds in aqueous solutions.
Precipitation is a type of a double-displacement reaction.
When do precipitates form in chemical reactions?
When the product of a reaction between cations and anions is insoluble in water.
Solubility rules help predict the formation of a precipitate.
True or False:
All silver salts are soluble.
False
Most silver salts are insoluble, with exceptions like silver nitrate (AgNO₃) and silver acetate (AgC₂H₃O₂).
What is the purpose of a molecular equation?
It represents the full chemical reaction, showing all reactants and products as compounds.
It does not separate compounds into their ionic forms.
Define:
spectator ions
Ions that remain unchanged on both sides of a chemical reaction and do not participate in forming the product.
They are removed when writing the net ionic equation.
List the five steps to write a net ionic equation.
- Write the balanced molecular equation.
- Identify substances that ionize.
- Write the complete ionic equation.
- Cancel spectator ions.
- Write the net ionic equation.
These steps help isolate the chemical species involved in forming the precipitate.
The net ionic equation represents chemical species directly involved in the reaction, excluding spectator ions.
List the three types of precipitation reactions.
- Precipitation in a solution.
- Precipitation in agar gel.
- Precipitation in agar gel with an electric field.
These methods differ based on the medium in which precipitation occurs.
True or False:
Group I element salts are generally insoluble.
False
Salts of Group I elements are generally soluble in water.
True or False:
Hydroxide salts of Group II elements are highly soluble.
False
Hydroxide salts of Group II elements are only slightly soluble.
Which ions are usually insoluble:
carbonate or nitrate
Carbonate
Most carbonates are insoluble, while nitrates are generally soluble.
Define:
displacement reaction
A reaction where one element replaces another in a compound.
The replaced element must have similar chemical properties to the replacing element.
What does a double displacement reaction involve?
Two compounds reacting to form two new compounds.
Double displacement reactions differ from single displacement by involving no uncombined element.
What is an example of a double-replacement reaction?
Reaction of NaCl(aq) and AgNO₃(aq) to form AgCl(s) and NaNO₃(aq).
Double-replacement reactions involve swapping cations or anions between two ionic compounds.
Define:
single displacement reaction
A + BC → AC + B
A unbonded element replaces an ion in a compound.
A is an unbonded element that replaces ion B in the compound BC.
What is the activity series of metals?
A ranking of metals based on their relative reactivity; It provides a qualitative comparison of the reactivities of elements.
Metals higher in the series are more reactive and can displace metals lower in the series.
Alkali and alkaline earth metals rank high in the activity series.
True or False:
Potassium is more reactive than magnesium.
True
Potassium is ranked higher than magnesium in the activity series of metals.
How can you determine if a reaction will occur using the activity series?
Compare the positions of the metals in the reactants on the activity series.
If the uncombined metal is higher than the compound’s metal, a reaction occurs.
Which non-metal is the most reactive according to the activity series?
Fluorine
Fluorine is the most reactive non-metal, replacing less reactive non-metals like iodine.
How does atom size affect reactivity in the activity series?
Larger atoms with fewer valence electrons are generally more reactive.
Reactivity increases with easier electron donation or acceptance.
How is an electrochemical chart different from an activity series?
It provides numerical values for reactions.
The activity series offers a qualitative comparison of reactivities.
