Unit 2 Lesson 7: Matter conservations Matters

Question 1

What does the law of conservation of matter mean?

Answer 1

According to the law of conservation of matter, matter cannot be created or destroyed, but it can change forms.

Question 2

What happens during a chemical reaction?

Answer 2

During a chemical reaction, the chemical structure of matter changes to form a new substance. This process requires breaking bonds between atoms and forming new bonds. When this occurs, the number of atoms in the reactants and the products remain the same. The reactants are the inputs of a chemical reaction, and the products are the outputs.

Question 3

What is the coefficient of a chemical formula? What does it indicate?

Answer 3

The number in front of the chemical formula is a coefficient, which indicates the number of molecules.

Question 4

2H20 what does the 2 infront of the h mean?

Answer 4

the number 2 in front of H2O
indicates that there are two water molecules in the reactants.

Question 5

In 2H2o what does the 2 after the hydrogen mean? What is a subsricpt?

Answer 5

The number 2 after the hydrogen is a subscript. It indicates that there are two hydrogen atoms in each water molecule.

Question 6

What if there is not coefficient or subsript?

Answer 6

If there is no coefficient or subscript it is assumed the number is 1.

Question 7

How do you calculate the total number of atoms in a chemical formula?

Answer 7

. To calculate the total number of atoms, multiply the coefficient by the subscript.

Question 8

Are the number of atoms in the the products and the reactants the same or differnt?

Answer 8

The number of each type of atom is the same in the products and in the reactants.

Question 9

Cellular respiration consists of a series of chemical reactions in which glucose and oxygen form ATP, water, and carbon dioxide. One of the major steps of cellular respiration is the Krebs cycle. What happens during the Krebs cycle?

Answer 9

This cycle consists of a series of chemical reactions that change the size and structure of carbon-based molecules. During each of these reactions, the numbers and types of atoms in the reactants equal the numbers and types of atoms in the products.

Question 10

What happens to glucose during the Krebs cycle?

Answer 10

Glucose molecules are broken down via the Krebs cycle to provide energy to power cells. Glucose is a carbohydrate molecule made up of carbon, hydrogen, and oxygen. But in other parts of our bodies simple carbohydrate monomers (glucose and fructose) are being linked together by covalent bonds (when atoms share an electron) to form chain-like molecules called polymers.

Question 11

What are Covlant bonds the result of

Answer 11

Covalent bonds are the result of a dehydration reaction, where one sugar releases a hydroxyl group (–OH)
and the neighboring sugar releases a hydrogen (–H)
.

Question 12

What is a dehydration reaction?

Answer 12

a dehydration reaction, where one sugar releases a hydroxyl group (–OH) and the neighboring sugar releases a hydrogen (–H)

Question 13

What forms water?

Answer 13

Together the hydroxyl group and hydrogen form water. The sugars both bond to the remaining oxygen.

Question 14

Cellulose vs arthropods

Answer 14

Cellulose is a polysaccharide that is a major component of the cell walls of plants. Chitin is a polysaccharide used by arthropods to build their exoskeleton. Cellulose and chitin are similar, both using carbon, hydrogen and oxygen. But chitin contains nitrogen and cellulose does not.

Question 15

What are the foundations of lifr?

Answer 15

Carbon-based molecules, in various combinations with nitrogen, hydrogen, oxygen, and occasionally sulfur, are the foundations of life on Earth.

Question 16

Which statement is true about the chemical reaction for photosynthesis in which carbon dioxide and water react to form glucose and oxygen?

1. Glucose and oxygen have a higher total mass than carbon dioxide and water.
2. The number of carbon atoms in the reactants and products are equal.
3. Light energy destroys some of the matter during the reaction.
4. The process of photosynthesis is a physical change.

Answer 16

The number of carbon atoms in the reactants and products are equal.

Question 17

A student is performing a chemical reaction. The mass of Reactant 1 is 33 grams. The mass of Reactant 2 is 57 grams. The reaction forms a solid and a gas. The mass of the solid is 26 grams. What is the mass of the gas?

Answer 17

The mass of the gas is 64 grams. The total mass of the products equals the total mass of the reactants.

Question 18

Give an example of a chemical change. Explain how matter is conserved during chemical changes.

Answer 18

Sample answer: An example of a chemical change is the rusting of iron in the presence of water and oxygen. Iron and oxygen combine to form iron oxide. When rust forms, the total amount of matter in the rust equals the mass of the reactants (iron and oxygen).

Question 19

Glucose can react with nitrogen compounds to form amino acids. Is matter conserved during these reactions? Explain your reasoning.

Answer 19

Yes, matter is conserved. All of the atoms in glucose and the nitrogen compounds are also present in the products. I know this because matter cannot be created or destroyed.

Question 20

The chemical reaction for photosynthesis is as follows:

6CO2 + 6H2O → C6H12O6 + 6O2
Explain how this reaction shows the conservation of matter.

Answer 20

The reactants and the products both have 6 carbon atoms, 18 oxygen atoms, and 12 hydrogen atoms. This shows that matter is not created nor destroyed during the reaction.

Question 21

Describe how you could demonstrate the law conservation of matter when water changes states. In your answer, describe the evidence you would use to support your argument.

Answer 21

I could measure the mass of each state of matter on a mass balance. For example, I could put ice in a sealed container and put it on the balance to measure its mass. I could then wait for the ice to melt and measure the mass again. The mass will be the same because matter is conserved. If I was making steam from liquid water, I could use a device to capture the steam and measure the mass of the steam that forms.

Question 22

What are the reactants of photosynthesis?

Answer 22

water and carbon dioxide are the reactants of photosynthesis

Question 23

What are the products of photosynthesis?

Answer 23

The products of photosynthesis are glucose and oxygen.

Question 24

What happens when an animal eats another animal

Answer 24

When an animal eats a plant, the animal’s digestive system converts the matter in the plant into the biomolecules the animal needs to grow and survive. Animals also release waste products into the environment. A similar process happens when an animal eats another animal. Some of this matter is used to grow or repair the animal’s body, and some matter is released as waste. The total amount of matter any plant or animal takes in is conserved.

Question 25

DEscribe the carbon cycle

Answer 25

The carbon cycle below shows how carbon changes form as it cycles through living things and the environment. Plants take in carbon dioxide from the atmosphere during photosynthesis. This carbon becomes part of glucose. When an animal eats the plant, the carbon in the glucose is used to make other biomolecules in the animal’s body. Some of this carbon is eventually released back into the environment as carbon dioxide or as digestive waste. When the animal dies, bacteria and other decomposers consume the biomolecules in the animal’s body and release carbon dioxide into the atmosphere. The decomposers also break down solid waste excreted by the animal. Oil, natural gas, and other fossil fuels contain carbon from organisms that lived thousands of years ago. When these fuels are burned, the carbon in these fuels is released back into the atmosphere as carbon dioxide. Carbon changes form as it cycles through living things, but the total amount of carbon in the system is conserved.