Chemical Reaction ( Change, Properties , Law COM) -EOG 2022

Chemical Reaction ( Elements , Compounds Mixture ,Change, Properties , Law COM) -EOG 2022

By Garfield Baker

Tes​t Taking strategies

1. Read the Entire Question

2. Read all the Answer Choices

3. What is the question really asking you ? ( Put in your own words)

4. Highlight key terms and vocabulary.

5. What topic was this completed under?

6. Eliminate choices that do not make sense

7. Pick the best answer

Multiple Choice

The image below shows models that represent the reactants and products of a chemical reaction.Based on the above image, which of the following is true?

• Mass was conserved in this chemical reaction because the same atoms are present in both the products and the reactants.

• Mass was lost in this chemical reaction because the atoms in the reactants are smaller than the atoms in the products.

• Mass could have either been gained or lost during this chemical reaction because atoms always change mass when they react.

• Mass was gained in this chemical reaction because there are more atoms in the products than there were in the reactants.

Multiple Choice

How are compounds related to elements?

• Elements are pure substances, and compounds are mixtures of two or more elements that are physically combined.

• Compounds are mixtures composed of molecules, and elements are pure substances composed of atoms.

• Compounds are pure substances that include two or more elements that are chemically combined.

• Elements are composed of energy, and compounds are composed of atoms.

Multiple Choice

Which of the following is a chemical compound?

• Co
•  CO₂
• Mg
• Al

Multiple Choice

Which element is found in air?

• Neon
• Carbon
• Oxygen
• Hydrogen

Multiple Choice

Milk is a:

• Element
• Compound
• Solid
• Mixture

Multiple Choice

Compounds are two or more elements that are chemically bonded together.

• True
• False

Multiple Choice

Which of these is a compound that is part of the processes shown in the picture?

•  CO₂
• Sunlight
• NaCl
• Oxygen

Multiple Choice

Which is classified as an element?

• Carbon Dioxide

• Vinegar

• Iron

• Water

Multiple Choice

When heated, calcium carbonate goes through a chemical reaction, and produces calcium oxide (quick lime) powder and carbon dioxide gas. A chemist performed this reaction in a lab and found that the mass of the calcium oxide (quick lime) was less than the mass of the calcium carbonate. What is the reason behind this decrease in mass?

• The carbon dioxide molecules produced were unstable and lighter in mass

• Calcium oxide crystals produced break up at room temperature, leading to the difference in mass.

• The calcium oxide crystals produced were unstable and lighter in mass.

• Carbon dioxide is produced, and as a gas, it was not captured to measure its mass.

Multiple Choice

When iron reacts with oxygen, it forms iron oxide, or rust.

4 Fe + 3 O₂  ------  2 Fe₂O₃

If 112 g of iron (Fe) combines with 24 g of oxygen (O₂), how much iron oxide is formed?

• 136 g Fe₂O₃

• 24 g Fe₂O₃

• 88 g Fe₂O₃

• 112 g Fe₂O₃

Multiple Choice

The balanced equation for the production of sugars by photosynthesis is shown below. This equation demonstrates the law of conservation of mass because

• the sugar molecule on the right has the same mass as the carbon dioxide molecules on the left.

• there is the same number of compounds on the right side of the equation as the left.

• there are more oxygen atoms on the right side of the equation than on the left

• there is the same number of each type of atom on the right side of the equation as the left

Multiple Choice

Which of the following equations is balanced correctly?

• 2 C₂H₂ + 5 O₂ → 4 CO₂ + 2 H₂O

• 2 C₃H₃ + O₂ → 2 CO₂ + H₂O

• Cl₂ + 2 KBr → KCl + Br₂

• 3 H₂O → H₂ + 3 O₂

Multiple Choice

Which of the following is true about the mass of the reactants in a chemical reaction?

• The total mass of the reactants in a chemical reaction will be significantly more than the total mass of the products.

• The total mass of the reactants in a chemical reaction will never be equal to the total mass of the products.

• The total mass of the reactants in a chemical reaction is conserved and will be equal to the total mass of the products.

• The total mass of the reactants in a chemical reaction will be significantly less than the total mass of the products.

Multiple Choice

Which statement below is also true of the rearrangement of atoms?

• The amount of matter decreases

• The number of substances is conserved

• The number of substances increases

• The amount of matter is conserved

Multiple Choice

A green powder is heated & a gas is given off while it turns to a black solid. This describes

• Physical Change

• Chemical Change

• Change in State

• Change in Temperature

Multiple Choice

Which of the following could indicate that a chemical change took place?

• Change in color

• Production of Energy

• Formation of Gas

• All are correct

Multiple Choice

What does a chemical change result in?

• A change in state of the substance (ex. liquid to solid)

• A change in texture of the substance.

• A change in the way atoms are bonded to each other.

• A change in the appearance of the substance.

Multiple Choice

Identify what type of change happening in the picture below...

• Chemical Change

• Physical Change

• Endothermic Reaction

• Exothermic Reaction

Multiple Choice

Identify what type of change happening in the picture below...

• Chemical Reaction

• Physical Change

• Change in State

• Change in appearance only

Multiple Choice

If the chemical properties of a substance remain unchanged & the appearance or shape of an substance changes it is a...

• Chemical Change

• Physical Change

• Both a physical and chemical change.

• Neither a physical or chemical change.

Multiple Choice

Which of the following is an example of a physical change?

• A glass falling and shattering on the floor.

• Baking a birthday cake.

• Burning a piece of paper.

• Baking soda and vinegar mixing together.

Multiple Choice

Which type of change are irreversible?

• Chemical Changes

• Physical Changes

• Changes in State

• Changes in Temperature

Multiple Choice

Aurelia dropped a piece of metal into a beaker, and then she added acid to it. She saw colorless bubbles rising from the metal. The metal began to turn black. What type of change did Aurelia see?

• physical, because the metal changed color

• chemical, because a new gas was formed

• chemical, because the metal changed phase

• physical, because the acid changed phase