Alright so let's talk about the law of conservation of mass, the law of conservation of mass states exactly what it sounds like it should, mass is neither created or destroyed during a chemical change and it's conserved so we are only going to be able to change mass or change matter, we're not allowed to actually create matter out of nothing or destroy matter into nothing. Alright so how is this helpful in dealing with chemi- in dealing with chemical reactions, here's a scenario that we might use to employ the law of conservation of mass.
Alright let's say we have an experiment we have 10 grams of red mercury 2 oxide and it's placed in an oven flask and it's heated until all of it decomposes and it decomposes into it's elements mercury and oxygen and the liquid mercury has a mass of 9.26 grams, what is the mass that of oxygen that gas that is formed. Alright so we started off with a mass of 10 grams of mercury 2 oxide okay we're going to take this sign this is saying here are the reactants reacted to decomposing into its products we're going to say this is equal 2. We have mercury, mercury we measured in that's its 9.26 grams okay? And we wanted how much how much oxygen gas its given off, we don't know we also we do know that law of conservation of mass states we're not going to destroy any matter we can't create matter out of nothing so the same the mass on this side should equal the mass of the products, so we can just do a basic mathematical problem and subtract 9.26 from both sides and we come up with point 74 grams of oxygen gas that's given off okay so the law of conservation of mass is really easy and it's really it explains a simplest concept that we cannot create matter out of nothing we cannot destroy matter into nothing.
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5.1 The Law of Conservation of Matter
- Correctly define a law as it pertains to science.
- State the law of conservation of matter.
In science, a lawA general statement that explains a large number of observations. is a general statement that explains a large number of observations. Before being accepted, a law must be verified many times under many conditions. Laws are therefore considered the highest form of scientific knowledge and are generally thought to be inviolable. Scientific laws form the core of scientific knowledge.
One scientific law that provides the foundation for understanding in chemistry is the law of conservation of matterIn any given system that is closed to the transfer of matter (in and out), the amount of matter in the system stays constant.. It states that in any given system that is closed to the transfer of matter (in and out), the amount of matter in the system stays constant. A concise way of expressing this law is to say that the amount of matter in a system is conserved.
What does this mean for chemistry? In any chemical change, one or more initial substances change into a different substance or substances. Both the initial and final substances are composed of atoms because all matter is composed of atoms. According to the law of conservation of matter, matter is neither created nor destroyed, so we must have the same number and type of atoms after the chemical change as were present before the chemical change.
Before looking at explicit examples of the law of conservation of matter, we need to examine the method chemists use to represent chemical changes.
Concept Review Exercises
What is the law of conservation of matter?
How does the law of conservation of matter apply to chemistry?
The law of conservation of matter states that in any given system that is closed to the transfer of matter, the amount of matter in the system stays constant
The law of conservation of matter says that in chemical reactions, the total mass of the products must equal the total mass of the reactants.
- The amount of matter in a closed system is conserved.
Express the law of conservation of matter in your own words.
Explain why the concept of conservation of matter is considered a scientific law.
Matter may not be created or destroyed.