Teste Ia

Question 1

What is the chemical formula for water?

Answer 1

H2O

Question 2

True or False: The pH scale ranges from 0 to 14.

Answer 2

True

Question 3

Fill in the blank: The process of a solid turning directly into a gas is called _______.

Answer 3

sublimation

Question 4

What is the main gas produced during cellular respiration?

Answer 4

Carbon dioxide (CO2)

Question 5

Which element has the atomic number 6?

Answer 5

Carbon

Question 6

What is the term for a substance that increases the rate of a chemical reaction without being consumed?

Answer 6

Catalyst

Question 7

True or False: Acids have a pH less than 7.

Answer 7

True

Question 8

What is the name of the process by which plants convert sunlight into chemical energy?

Answer 8

Photosynthesis

Question 9

Which gas is commonly known as laughing gas?

Answer 9

Nitrous oxide (N2O)

Question 10

Fill in the blank: The __________ is the smallest unit of an element that retains the properties of that element.

Answer 10

atom

Question 11

What type of bond involves the sharing of electron pairs between atoms?

Answer 11

Covalent bond

Question 12

What is the molar mass of carbon dioxide (CO2)?

Answer 12

44 g/mol

Question 13

Which type of reaction involves a substance breaking down into simpler substances?

Answer 13

Decomposition reaction

Question 14

True or False: All chemical reactions involve a change in energy.

Answer 14

True

Question 15

What is the primary component of natural gas?

Answer 15

Methane (CH4)

Question 16

Fill in the blank: The __________ law states that mass is neither created nor destroyed in a chemical reaction.

Answer 16

law of conservation of mass

Question 17

What is the term for the amount of solute that can dissolve in a given amount of solvent at a specific temperature?

Answer 17

Solubility

Question 18

Which element is represented by the symbol ‘Na’?

Answer 18

Sodium

Question 19

What is the difference between an ionic bond and a covalent bond?

Answer 19

Ionic bonds involve the transfer of electrons, while covalent bonds involve sharing electrons.

Question 20

True or False: Noble gases are highly reactive.

Answer 20

False

Question 21

What is the term for a solution that contains more solute than it can theoretically hold at a given temperature?

Answer 21

Supersaturated solution

Question 22

Which acid is commonly found in vinegar?

Answer 22

Acetic acid (CH3COOH)

Question 23

Fill in the blank: The __________ is a measure of the concentration of hydrogen ions in a solution.

Answer 23

pH

Question 24

What is the primary purpose of a buffer in a chemical system?

Answer 24

To maintain a stable pH

Question 25

Which type of reaction occurs when an acid and a base react to form water and a salt?

Answer 25

Neutralization reaction

Question 26

What is the term for the energy required to initiate a chemical reaction?

Answer 26

Activation energy

Question 27

True or False: The atomic number of an element is equal to the number of protons in its nucleus.

Answer 27

True

Question 28

What is the most abundant gas in the Earth's atmosphere?

Answer 28

Nitrogen (N2)

Question 29

Fill in the blank: A __________ is a substance that donates protons (H+) in a chemical reaction.

Answer 29

Bronsted acid

Question 30

What is the term for the process of a liquid turning into a gas?

Answer 30

Evaporation

Question 31

Which element is a liquid at room temperature?

Answer 31

Bromine (Br)

Question 32

What is the chemical formula for table salt?

Answer 32

NaCl

Question 33

True or False: All metals are good conductors of electricity.

Answer 33

False

Question 34

What is the process by which a gas turns into a liquid?

Answer 34

Condensation

Question 35

Fill in the blank: The __________ is the part of the atom that contains protons and neutrons.

Answer 35

nucleus

Question 36

What is the term for the temperature at which a liquid turns into a gas?

Answer 36

Boiling point

Question 37

Which type of radiation has the highest energy?

Answer 37

Gamma radiation

Question 38

What is the principle behind chromatography?

Answer 38

Separation of components based on their movement through a medium

Question 39

True or False: A strong acid completely dissociates in water.

Answer 39

True

Question 40

What is the molecular formula for glucose?

Answer 40

C6H12O6

Question 41

Fill in the blank: The __________ is the measure of the randomness or disorder of a system.

Answer 41

entropy

Question 42

What is the term for the energy stored in chemical bonds?

Answer 42

Chemical potential energy

Question 43

Which type of bond is formed by the attraction between positively and negatively charged ions?

Answer 43

Ionic bond

Question 44

What is the significance of the periodic table?

Answer 44

It organizes elements based on their properties and atomic structure.

Question 45

True or False: Isotopes of an element have the same number of neutrons.

Answer 45

False

Question 46

What is the term for the amount of heat energy required to raise the temperature of 1 gram of a substance by 1 degree Celsius?

Answer 46

Specific heat capacity