Chemical Reactions

What are examples of acids used in everyday life?

- An example of an acid is folic acid, which is found in green, leafy vegetables and is important for vegetable growth - Phosphoric acid is used to make plant fertilizers - Hydrochloric acid helps with digestion in the stomach - Sulfuric acid drives many types of batteries

What are the energy of the reactants and the overall change in energy represented by, in an exothermic reaction coordinate diagram?

- The energy of the reactants is represented by the initial flat portion, and the energy of the products is represented by the flat portion at the end. - The overall change in energy is represented by triangle E, and it is the difference between the starting energy and the final energy. - Triangle E = (Energy of the products) - (Energy of the Reactants) -Since the products and reactants have differing amounts of energy, chemical reactions involve some overall change in energy.

What is the basic structure of a chemical equation?

- These equations state the substances that you start with in a reaction, and the substances that are formed at the end as a result of the reaction. - Reactants are the substances at the beginning, and the products are the substances that are formed at the end of the reaction. - The reactants' formula is written on the left and they are followed by an arrow. The arrow represents the words "yields' or "reacts to form" - The products' formulas are written on the right of the arrow - Two or more reactants in a chemical equation are separated by a + sign , and similarly, + signs are used to separate 2 or more products

What are the steps for determining the number of atoms of one element in a chemical formula and ensure the balance of an equation?

1. The number in front of the chemical formula should be multiplied by the subscript on the atom in the chemical formula. The coefficient is the number in front of the chemical formula, and it indicates the number of atoms or molecules there are. 2. In a chemical formula, "1" is never written (CH4 is the same thing as 1C1H4) 3. On the reactant side, write the number of each type of atom and do the same for each type of atom on the product side. Then compare those numbers. These are the last few steps one should take to ensure the correct balance of the equation

What are 3 things that must be true for a chemical reaction to occur?

1. The particles of the elements must collide with one another, and in these rules, a particle just represents one unit, so a reactant's particle could be an atom, ion, molecule, or a formula unit 2. There must be enough energy (activation energy)for the particles to react, which means that these particles should be moving at a certain speed. The particles will not have enough energy to break old bonds and form new bonds as they're colliding. 3. These particles must have the proper orientation to react. Sometimes, these particles might collide with each other because of their constant, random movement. They react if they collide with enough energy and the right orientation

What are the steps for balancing a chemical equation?

1. The total number of atoms of each element in the reactants has to equal the total number of atoms of each element in the products 2. To write a balanced equation, write down the correct chemical formulas for both of the reactants and the products. Then, place the reactants on the left side of the arrow, and write the product on the right side of the arrow. After this, the number of atoms of each element on each side of the equation should be counted. The subscript is what tells you the ratio of the elements in a compound. 3. The coefficients should be changed so that the number of atoms of each element in the reactants is equal to the number of atoms of each element in the products. This would indicate a conserved mass and a balanced equation

How are the different parts of a decomposition reaction represented by AB ￫ A + B?

A and B represent the products and AB represents the compound

How are the different parts of a decomposition reaction represented by A + B ￫ AB?

A and B represent the reactants, and AB represents the product

What are examples of evidence that chemical reactions have taken place?

A color change, gas production. or precipitate formation

Give an example of concentration.

A cup of tea can become more sweet if more sugar is added. The cup of tea would have a greater concentration of sugar molecules

How are the different parts of a single displacement (or replacement) reaction represented by A + BC ￫ AC + B

A represents the reactant, BC represents the part of the compound taken up, AC represents the new compound, and B represents the separate product that is released

How does the chemical equation AB + CD ￫ AD + CB represent the different parts of a double displacement reaction?

AB and CD represent the two compounds that the chemical reaction takes place between, and AD and CB represent the two different compound products

How are acids able to conduct electricity?

Acids are able to conduct electricity since they dissociate (break down) into ions in a solution

What type of taste do acids have?

Acids tend to have a sour taste. Examples of fruits containing citric acids are lemons, grapefruit, and oranges, and vinegar and tomato are also foods that contain acids

What is another ion that acids react with?

Additionally, carbonate ions are another thing that acids react with. These ions consist of carbon and oxygen atoms chemically bonded together with an overall negative charge. Carbon dioxide is an example of a product of an acid and carbonate ion's reaction

What are chemical reactions?

Also called chemical changes, it is a type of change in matter that produces one or more new substances. When existing bonds break and new bonds are formed, chemical changes occur, causing new substances to be produced. When the atoms of one or more substances are rearranged so that one or more different substances are produced, a chemical reaction occurs. New substances containing different properties are formed from chemical reactions.

Give an example of a type of chemical reaction and what it is shown as.

An example of a chemical reaction is hydrogen and nitrogen's, which is shown as 3H2 + N2 ￫ 2NH3

Give another example of an endothermic reaction.

An exothermic reaction occurs when energy is added to aluminum oxide and produces metal and oxygen gas as a result energy + 2AI2O3 (s) ￫ 4AI (s) + 3O2 (g)

give another example of an exothermic reactions.

An exothermic reaction occurs when methan and oxygen react and prdouce carbon dioxide, water, and heat as a result CH4 (g) + 2O2 (g) ￫ CO2 (g) + 2H2O (I) + energy

How do catalysts change reaction rate?

At the beginning and end of a chemical reaction, a catalyst's identity and amount are the same. By changing the reaction pathway to avoid the highest-energy state, a catalyst usually lowers the activation energy. Changing the activation energy needed can control a reaction's rate

What is an example of an endothermic reaction?

Baking soda goes through an endothermic reaction when it is mixed with vinegar. The reactions feels cold because it absorbs the heat of its surroundings

What is the taste of bases like?

Bases have a bitter taste, an examples of familiar bases that are known to have bitter tastes are food that have bases: cocoa beans, almonds, bitter melon, etc.

Which two types of energy in a chemical reaction are independent of one another?

Both the activation energy and change in energy are independent of one another. The starting energy is the only thing that the change in energy depends on, and energies along the way do not affect the final energy (reactants and products).

Do changes in the matter always indicate chemical reactions? Why or why not?

Changes in the matter do not always indicate chemical reactions, for physical changes can give similar results. Ex: The gas bubbles form when water boils are made of water molecules, just like the liquid was. Sure evidence that a chemical reaction has taken place is when one or more new substances are produced.

In a diagram that illustrates a catalyst's effect on a reaction, what are the different parts represented by?

Changing the activation energy changes the reaction's rate. But, the products' energy or reactants' energy isn't changed by this, so Triangle E remains the same. The reaction's rate is independent of the overall change in energy.

How do chemists often initiate chemical reactions?

Chemists often initiate chemical reactions by adding a small amount of energy to it and producing much more energy

What is concentration?

Concentration is equal to the amount of substance per given volume

What are the few ways the rate of a chemical reaction can be increased?

Concentration, temperature, and catalysts can be used to do this.

Are all reactions that require energy to start classified as endothermic reactions?

Even though a reaction requires energy to start, that doesn't mean that it is an endothermic reaction. To get over the energy barrier, a certain amount of energy is needed by the endothermic reaction, but it releases more energy during the reaction than it takes to get started.

What are examples of exothermic reactions?

Examples of exothermic reactions are burning of fuels, like wood, oil, or natural gas

Give an example of how elements need and use activation energy?

Hydrogen and oxygen form water when they react, but just mixing the two gases isn't going to do anything. Activation energy needs to be added so that the reaction occurs. This way, a few of the hydrogen and oxygen molecules will react and produce energy as a result.

Give an example of the law of conservation of mass.

If 1 atom of iron reacts with 1 atom of sulfur, then at the end of the reaction, in the compound iron sulfide (FeS), there is 1 iron atom bonded to 1 sulfur atom

How does the concentration of substances depend on the pH level?

If a substance has a low pH level, then its concentration of hydrogen ions is high, and the concentration of hydroxide ions is low. The opposite is true with a high pH level

How does temperature increase/decrease reaction rate?

If particles are more likely to move faster, they are more likely to collide. These particles are also more likely to have more energy when two particles collide, and they are likely to have enough energy to react. Particles with more energy help reactants get over the activation energy barrier more quickly. Reducing temperature slows down reaction rates

What are indicators?

Indicators are used to test for acids, and an example of one is litmus paper, which is a compound that undergoes a color change when it comes into contact with an acid. Blue litmus paper is turned red by acids, due to the hydrogen ions, and red litmus paper is turned blue by bases

What does it mean to dissociate?

It means to "break down", or "to break apart"

give an example of a decomposition reaction.

Keeping a bottle of hydrogen peroxide for a very long time will give you water instead. Hydrogen peroxide decomposing into water and gas is an example of a decomposition reaction

How can bases be identified?

Lack of a reaction is a useful way of identifying bases. Bases do not react with metals like acids do, and they also don't react with carbonates to form carbon dioxide gas

What are the different parts of an endothermic reaction represented by in a reaction coordinate diagram?

Like exothermic reactions, endothermic reactions need activation energy, but they also need energy to continue. The products' energy is greater than the reactants' energy, so te reaction has to continuously absorb energy so that it can keep going. Most of these endothermic reaction require continuous energy This type of reaction shows how the products are at a higher energy level than the reactants. Triangle E, in this diagram, is the amount of energy needed to be put into the reaction. Triangle E is positive and gained by the reactants because its product energy is greater than the reactant's energy?

What happens when acids react with metals?

Metal salts and hydrogen can be produced when acids react with metals. Elements like copper, zinc, and iron react with most acids. The metals disappear in the solution when they react.

Give an example of a precipitate

Milk and lemon juice can form a precipitate when they mix to make curdled milk

What is an example of temperature reducing reaction rate?

Milk consists of bacteria, and that can carry out thousands of chemical reactions while living. Milk and other foods are stored in the refrigerator because the reactions are slowed down by keeping those foods cold, so the foods stay fresh for longer

What do most acids separate into?

Most acids separate into hydrogen ions (H+) and negative ions. There is an excess of hydrogen ions (H+) in an acidic solution. H+ ions are often donated by acids to bases. H+ ions are produced by an acid in water. The hydrogen ions produced are responsible for the corrosion of metals and turning blue litmus paper red.

What is another important property of bases?

Neutralization is another important property of bases of how they react with acids in a type of chemical reaction. During neutralization, acids and bases deactivate one another

What is conservation of atoms?

On the reactants' side, the number of atoms per element (on the left side of the arrow) must equal the number of atoms per element on the products' side (on the right side of the arrow). When the atoms on both sides are equal, the equation is balanced, which demonstrates the conservation of atoms is the equation is a balanced one. Not to mention, this equation also shows the lowest whole-number ratio of products to reactants. Atoms have to appear somewhere in the products of their reaction if they go into a reaction. Likewise, three hydrogen atoms must appear on the sie of the products if they appear on the reactants' side

Give na example of how particles increase reaction rate?

Particles are like people, and people are more likely to run into each other in a crowded room. The reaction rate increases as the concentration increases

Give an example of an inhibitor

Preservatives are inhibitors that are added to food so that they don't spoil

Give an example of a substance's pH value.

Pure water has a neutral pH due to its equal number of hydrogen ions and hydroxide ions

Give an example of a balanced equation, with CH4 (g) + 2O2 (g) ⇢ CO2 (g) + 2H2O (l)

Reactant side of the equation C: 1 x 1 = 1 H: 1 x 4 = 4 O: 2 x 2 = 4 Product side of the equation: C: 1 x 1 = 1 H: 2 x 2 = 4 O: (1 x 2) + (2 x 1) = 4 The reaction is balanced because the number of each type of atom is the same is the name for the reactants as it is in the products

What happens with reactants in a chemical reaction?

Reactants do not directly change into products when a chemical reaction occurs. For chemical bonds to be broken and made up, it takes time and energy to happen. Reactants are often arranged in multiple ways as the atoms shift around to become the final product.

What is a chemical reaction generally shown as?

Reactants ￫ Products

What are examples of everyday objects containing carbonate acid?

Seashells, eggshells, limestone, chalk, etc.

What happens with temperature in endothermic reactions?

Since these reactions absorb their environment's heat, they would feel cold to the touch, and the products in these reactions are less stable (higher in energy) than the reactants. There isn't a temperature decrease in all endothermic reactions, and most of these reactions occur when there is an amount of heat constantly added.

What are the two types of chemical reactions?

Some chemical reactions require the input or release of energy. These are called exothermic and endothermic reactions.

What are the ranging values on the pH scale?

Substances generally range from 0 to 14 on the pH scale. Substances that have a pH value less than 7 are acids, and substances that have a pH value greater than 7 are bases. A substance is more acidic if it has a smaller number on the pH scale, and it is more basic if it has a higher number on the pH scale. A substance that has a pH of 7.0 is neutral, meaning that it is not acidic or basic.

What is temperature?

Temperature is measure of how fast particles are moving in a substance, which is kinetic energy

What is the activation energy represented by, in an exothermic reaction coordinate diagram?

The activation energy is represented by Ea. Ea = (energy of the transition state) - (energy of the reactants)

Who was Antoine Lavoisier (1743 - 1794)?

The chemist who proposed the law of conservation of mass' first version. The law states that the increase/decrease in matter's quantity was unnoticeable throughout an ordinary chemical change. Lavoisier switched chemistry to be a quantitative science from a qualitative science. He was also the founder and namer of oxygen, and found of oxygen's role in combustion

What are coefficients?

The coefficient is the number in front of the chemical formula, and it indicates the number of atoms or molecules there are. The coefficients should be changed so that the number of atoms of each element in the reactants is equal to the number of atoms of each element in the products. This would indicate a conserved mass and a balanced equation

Give an example of an exothermic reaction releasing heat.

The energy released is usually heat. There are some stoves that use natural gas, and natural gas releases heat when it burns. Food is cooked by the heat released from the natural gas

How does concentration increase reaction rate?

The reactants' higher concentration increases the number of particles in the same amount of space, making it more likely for particles to run into each other.

What is a solution's acidic content based on?

The solution's acidic content is based on the hydrogen ions concentration in the solution. The solution becomes very acidic when a lot of the hydrogen ions are released into a solution

What are some of the different uses for bases, and what is their effect on some things?

There are many different uses for bases. For example, ammonia is used in household cleaners and fertilizers. Baking soda causes baked goods to rise and is called sodium bicarbonate. Bases are commonly used for making soaps and feel slippery when they are touched.

What are the ways to identify a chemical reaction?

There are many ways to detect chemical reactions and one of those ways is identifying and observing changes with physical and chemical properties. When new substances form, properties change. The reactants interact to form products with different chemical properties during a chemical reaction

Why is there no such thing as decimals in a balanced equation?

There should be no decimals in a balanced equation because there is no such thing as half a molecule or one-fourth of a molecule, So, we eliminate this number by multiplying all of the coefficients by 2

What are acids?

These are substances that release ions of hydrogen when they are dissolved in water, and they have specific characteristic properties and are very important in our lives. There are some acids that can dissolve metals, and others that are corrosive in nature.

How are chemical equations different from mathematical equations?

These equations differ from mathematical equations because both of the sides are separated by an arrow so that it can be shown that the reactants form the products. Symbols are used instead of words in these equations, and these equations are shorter than sentences but still contain a lot of information

Give an example of a single displacement reaction with the equation Mg (s) + 2HCI (aq) ￫ MgCI2 (aq) + H2 (g)

This is a displacement reaction that occurs when a piece of solid magnesium metal combines with some aqueous (aq) hydrochloric acid. These reactants produce 2 products when they combine: aqueous magnesium chloride and hydrogen gas (g)

Give an example of a double displacement reaction with Fe2O3 (s) + GHNO2 (aq) ￫ 2FE(NO3)3 (aq) + 3H2O (I)

This is a double displacement reaction where iron (III) oxide combines with nitric acid. As a result of this reaction, iron (III) nitrate and water are produced

Who came up with the law of conservation of mass?

This law was demonstrated by Antoine Lavoisier in 1774, who was a French chemist

What are the different parts of an exothermic reaction represented by in a reaction coordinate diagram?

Triangle E is the difference between the reaction's released amount of energy, in the exothermic reaction. The exothermic reaction above follows the pattern, the dotted line represents the reactants' energy before it begins. The peak of the graph represents the activation energy. At the end of the reaction, the products have less energy than the reactants, meaning it shows that the products are at a lower energy level than the reactants. An energy release is what this type of reaction results in. Triangle E is negative and lost by the reactions since it is equal to (energy of the products) - (energy of the reactants).

Give an example of an element coming in contact with an acid.

When magnesium and hydrochloric acid come into contact, the metal and the acid react. As a result, magnesium chloride (a salt) and hydrogen gas are produced Mg (s) + 2HCI (aq) →MgCI2 (aq) + H2 (g)

What is a double displacement (or replacement reaction)?

a chemical reaction that occurs between two compounds where part of a reactant switches places with a different part of a reactant. Both of the elements are arranged in such a way that two or more different compound products are formed

What are reactants?

a chemical reaction's starting material (s). They undergo chemical reactions

What is a reaction coordinate diagram?

a diagram that plots the energy's reaction, along with the molecules and atoms involved instead of plotting how far the reaction has progressed. All of the atoms and molecules that are lower in energy are more stable, and they are less stable when they are higher in energy. Chemical compounds attempt to move towards a state that is lower in energy because it is more stable.

What is the Law of conservation of mass?

a law that states that matter can be changed, but not created or destroyed. The idea states that all atoms that are present at the start of a chemical reaction are present at the end as well. All of the atoms in the reactants are also present in the products. This law also states that the reactants' mass must equal the products' mass, and the conservation of the number of atoms in that reaction since atoms make up all matter.

What is the transition state?

a state that is higher in energy and a state that the reactants have to pass through in order to get the products. Bonds in the reactants are in process of breaking, and the bonds in the products are in the process of forming, during the transition state. This state is the highest in energy in the reaction coordinate diagram

What are catalysts and how do they affect reaction rate?

a substance that changes a reaction's rate. They are often used to increase the reaction rate, and they do this by making it easier for the reaction to take place. Catalysts are not considered to be reactants and are not changed permanently by a reaction.

What is color change?

a type of change in color that is another way of indicating another substance has been formed. Ex: When avocados react with oxygen in the air, they turn brown

What are physical changes?

a type of change in matter that doesn't later a substance's form or appearance (Ex: Cutting an apple in half is a physical change)

What are single displacement (or replacement) reactions?

a type of chemical reaction that occurs when some part of a compound's place is taken up by a reactant. Due to this, a separate product is released and a new compound is made

What is a synthesis (or combination) reaction?

a type of chemical reaction where small molecules combine and form a larger molecule. This reaction occurs when two or more elements or compounds combine and make a more complex substance. The product is formed when two or more reactants combine. Ex: reaction of phosphorus with oxygen is a synthesis reaction

What is a chemical equation?

a type of equation that describes a chemical reaction when it occurs. To describe the reaction, it uses chemical symbols and formulas, which represent the reactants and products in the reaction. The involvement of heat, light, or radiation can be shown by these equations, as can the reactants' and products' physical states.

What is Gas Production?

a type of observable change in a chemical reaction, where a gas is formed from solid or liquid reactants. The gas usually appears as bubbles

What is precipitate?

a type of solid that is formed from liquids during a chemical reaction. Mixing two liquids may cause a precipitate to form.

What are alkalis?

bases made from ionic salts of an alkali metal or an alkaline earth metal. Although all alkalis are bases, not all bases are alkalis. The word 'alkali" is commonly used as a synonym for base, but it is not the same thing.

What are exothermic reactions?

chemical reactions that produce energy. Exothermic reactions often produce energy in the form of light, heat, or sound. When the reactants lose energy, their energy is released to the reaction's environment. The energy that is released during the formation of the products is greater than the energy needed to break the reactants' bonds. A exothermic reaction's products are more stable, or lower in energy than the reactants.

What are endothermic reactions?

chemical reactions that require energy input into it. In these reactions, there is more energy that is needed to break the reactants' bonds than it is released by the products' formation. In the form of heat or light often, these reactants gain energy by taking the energy from their environment.

What is the collision theory?

frequency of particles colliding with each other successfully and their reacting determining the reaction rate

What do the symbols (g), (l), (sq), and (aq) represented when they are shown in a chemical equation of a chemical reaction? ex: 2H2 (g) + O2 (g) ￫ 2H2O (I)

hey represented the phases of the different compounds in the reactions. So, if a compound has (g) after it, then it is a gas. If it has (l), it is a liquid, and with (s), it is a solid. There may also be (aq) which means aqueous solution (compound's liquid mixture with water as the solvent)

What are inhibitors?

materials that are used to decrease a chemical reaction's rate, opposed to speeding it up.

What is the pH scale?

measures a solution's acidity. A solution's pH states its acidity or how basic it is by measuring the concentration of H+ (hydrogen) ions in a solution. The pH of a solution can be found with indicator paper, which ranges with colors for each pH value

What are salts?

molecules that release ions other than hydrogen ions when dissolved in water

What are hydrogen ions?

one of hydrogen's atoms that has lost its electron. Hydrogen ions and chloride ions form in the case of hydrochloric acid

What is a decomposition reaction?

opposite of a synthesis reaction, where a chemical reaction where the compound breaks down into two or more products. An energy source from outside is what most decomposition reactions need to occur.

What is activation energy?

the minimum amount of energy needed for the reaction to overcome the energy barrier. It is the energy that reactants need to go from reactants to the transition state. Each chemical reaction needs its own specific amount of energy to get started. This energy is needed so that new bonds can be made, so they are needed to break bonds that exist.

What is the reaction pathway?

the road taken by atoms and molecules to get from starting materials to products. The reactants' total energy changes as they change, and it changes as the bonds are broken and remade

What are products?

the substance (s) produced from a chemical reaction. One or more of these products can be classified as byproducts sometimes.

What are bases?

types of substances that release hydroxide ions (OH-) when they are dissolved in water. These are groups of compounds that can be identified by their common properties. Bases have properties that are the opposites of acid's properties, and they turn red litmus paper blue and feel slippery. There are strong bases that can harm human skin. There is an excess of OH- ions in a basic solution and bases usually give their OH- ions to acids

Give a 2nd example of a decomposition reaction

Δ 2HgO (s) ￫ 2Hg (l) + O2 (g) This is a decomposition reaction where Mercury (ll) oxide (HgO) split into mercury and oxygen gas. Above the arrow, there is small triangle which is representing how the reaction needs energy to take place.