Observing Chemical Change
Describing Chemical Reactions
Controlling Chemical Reactions
Fire and Fire Safety
100
What is matter, and what is the study of it?
Matter is anything that has mass and takes up space, and the study of matter is called chemistry.
100
What is a chemical formula?
A chemical formula is in an equation using reactants that act as addends and a product that acts as a sum. They are used in a chemical equation to make reactions shown shorter.
100
What is the difference between endothermic and exothermic reactions?
What is the difference between endothermic and exothermic reactions? Endothermic reactions are reactions in which energy is absorbed, and exothermic energy is one in which energy is released.
100
What are three components of the fire triangle?
The three components of the fire triangle are oxygen, fuel (such as dry wood) and heat.
200
What is the difference between a physical property and a chemical property?
A physical property is a characteristic of a substance that can be observed without changing of the substance such as ice melting, and chemical properties are characteristics that describe a ability to change into other substances such as burning of magnesium.
200
Is a closed system or open system more useful for calculating the total mass of a chemical reaction?
A closed system, or system in which matter cannot come in or our in and a open system, in which matter comes in an out of would not have to matter for finding mass in a reaction because the conservation of mass states that the same amount of mass is there after a reaction as was before.
200
How does surface area change the activation energy of a chemical reaction?
Surface are needs to be completely covered in a chemical reaction to change, so the less the surface area, the smaller the activation energy required to get a reaction.
200
What would happen to the fire if a nonflammable case was put over it.
If fire had anything covering it that wouldn't burn, it's supply of oxygen would go away and the fire would die because it needs to have all three parts of the triangle.
300
Describe the difference between a physical change and a chemical reaction.
A physical change is any change involving the form or appearance of a substance, and a chemical reaction is a change in matter that causes one substance to change into another.
300
In the equation, H2O, how can it be balanced using conservation of mass and coefficients?
If two hydrogen and two oxygen atoms make H2O, then one oxygen atom is lost, which breaks conservation of mass rule. So, using a coefficient of 2 in front of H2 in the first side, and also two in front of H2O on other of the arrow, the equation is balanced.
300
How do particles in matter change when heated, and how can this affect a chemical reaction?
Particles move faster when they are heated, which can cause them to come in contact more often, which gives a higher reaction rate, and faster moving particles have a higher amount of energy so that the amount of activation energy can be met.
300
How can fire be fought if unable to be prevented?
Fire can be stopped with carbon dioxide, which would separate the fuel from the oxygen. Also you could put water over it, which would cause evaporation that takes up most of the heat, and you could put baking soda over it which would decompose when heated and releases carbon dioxide.
400
How are bonds and chemical change related?
Chemical changes occur when bonds break and new bonds are formed, therefore new substances are produced. Atoms form bonds by sharing or transferring electrons which causes chemical reactions to form.
400
Is the reaction FeS+2 HCI---> FeCl2+ H2S as synthesis, decomposition, or replacement, and explain why.
The reaction FeS+2 HCI---> FeCl2+ H2S is an example of replacement because the compounds FeS, S trades with Cl, so there is a replacement of 2 instead of one.
400
Define concentration.
Concentration is the amount of substance in a given volume, when decreased a reaction rate is much higher.
400
What would cause a fire to stop?
A fire stops when any one part of the triangle runs out, which can happen naturally, like no wood being in the pit anymore, or something happened to it by force.
500
How can you tell a chemical reaction will occur?
How can you tell a chemical reaction will occur? A chemical reaction can be told by changes in color, turning into a solid called a precipitate, or a gas being produced that can be shown as bubbles, or changes shown by sight.
500
What is the difference between Synthesis, replacement, and decomposition?
Synthesis, replacement, and decomposition are all types of chemical reactions. Synthesis is the combining of two elements, decomposition is when one element "breaks down" to another, and replacement is when two elements trade places.
500
What is the difference between catalysts and inhibitors?
What is the difference between catalysts and inhibitors? Catalyst is a material that increases the rate of reaction by lowering the activation energy required. An example of catalysts in your body are enzymes. Inhibitors are materials that decrease the reaction rate by slowing it down. Most inhibitors work by preventing reactants to come together.
500
How can fire be prevented?
You can prevent fire by having a fire extinguisher, alarm, and baking soda in your house. You also can make sure flammable items are away from flames.
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