Chapter 1

Question 1

What does the flame symbol indicate in scientific safety?

Answer 1

The flame symbol indicates flammable materials.

Question 2

True or False: The skull and crossbones symbol is used to indicate toxic substances.

Answer 2

True

Question 3

Fill in the blank: The __________ symbol indicates that a substance may cause an explosion or is reactive.

Answer 3

explosion

Question 4

Which safety symbol is used for corrosive substances?

Answer 4

The test tube pouring a liquid onto a hand and a surface.

Question 5

Multiple Choice: What does the exclamation mark symbol represent? A) Flammable B) Irritant C) Corrosive

Answer 5

B) Irritant

Question 6

What does the gas cylinder symbol represent?

Answer 6

It indicates gases under pressure.

Question 7

True or False: The environmental hazard symbol is used for substances harmful to aquatic life.

Answer 7

True

Question 8

Fill in the blank: The __________ symbol indicates that a substance is harmful if inhaled or absorbed through the skin.

Answer 8

health hazard

Question 9

What is the purpose of safety symbols in scientific settings?

Answer 9

To communicate hazards and ensure safety in handling materials.

Question 10

Multiple Choice: Which symbol indicates that a substance is an oxidizer? A) Flame B) Flame over circle C) Skull and crossbones

Answer 10

B) Flame over circle

Question 11

What is the basic unit of electrical charge in an atom?

Answer 11

The basic unit of electrical charge in an atom is the electron.

Question 12

True or False: Protons have a negative electrical charge.

Answer 12

False: Protons have a positive electrical charge.

Question 13

Fill in the blank: An atom that has more electrons than protons is called a __________.

Answer 13

anion

Question 14

Which subatomic particle carries a positive charge?

Answer 14

Proton

Question 15

Multiple Choice: What is the charge of a neutron?

Answer 15

Neutral

Question 16

What is the relative mass of a proton, neutron and electron

Answer 16

1, 1, 0

Question 17

What is the electrical charge of a proton, neutron and electron

Answer 17

+1, 0, -1

Question 18

What is an element

Answer 18

A pure substance which can only be broken down further into atoms

Question 19

What is a compound

Answer 19

A substance which contains two or more chemically bonded atoms

Question 20

What is an atom

Answer 20

The most small and basic particle, used to make elements when combined

Question 21

What is a molecule

Answer 21

A substance with multiple atoms

Question 22

What is a mixture

Answer 22

Elements, atoms and compounds mixed together

Question 23

What is a chemical formula?

Answer 23

A representation of a substance using symbols for its constituent elements and numerical subscripts to indicate the number of atoms.

Question 24

True or False: The formula H2O represents water.

Answer 24

True

Question 25

Fill in the blank: The chemical formula for sodium chloride is _____.

Answer 25

NaCl

Question 26

Which of the following is a molecular formula? A) C3H8 B) NaCl C) CaCO3

Answer 26

A) C3H8

Question 27

What does the subscript in a chemical formula indicate?

Answer 27

The number of atoms of the element in one molecule of the compound.

Question 28

Name the chemical formula for carbon dioxide.

Answer 28

CO2

Question 29

Multiple Choice: Which of the following formulas is an empirical formula? A) C6H12O6 B) CH2O C) C2H4

Answer 29

B) CH2O

Question 30

Short Answer: What is the difference between a molecular formula and an empirical formula?

Answer 30

A molecular formula shows the actual number of atoms of each element in a molecule, while an empirical formula shows the simplest whole-number ratio of the elements.

Question 31

True or False: The formula for ammonia is NH3.

Answer 31

True

Question 32

What is the significance of parentheses in a chemical formula?

Answer 32

Parentheses are used to indicate groups of atoms that act as a single unit within a compound.

Question 33

What is the definition of oxidation in chemistry?

Answer 33

Oxidation is the process where an atom, ion, or molecule loses electrons.

Question 34

True or False: Oxidation always involves the addition of oxygen.

Answer 34

False

Question 35

Fill in the blank: In a redox reaction, the substance that gets oxidized is called the __________.

Answer 35

reducing agent

Question 36

Which of the following elements commonly undergo oxidation: A) Hydrogen B) Carbon C) Iron?

Answer 36

All of the above

Question 37

What is the oxidation state of carbon in carbon dioxide (CO2)?

Answer 37

+4

Question 39

What does the law of conservation of mass state?

Answer 39

Matter cannot be created or destroyed in a closed system.

Question 40

True or False: The total mass of reactants in a chemical reaction is always equal to the total mass of the products.

Answer 40

True

Question 41

Fill in the blank: In a chemical reaction, the mass of the _____ is equal to the mass of the _____ produced.

Answer 41

reactants, products

Question 42

Which scientist is most commonly associated with the formulation of the law of conservation of mass?

Answer 42

Antoine Lavoisier

Question 43

Multiple Choice: Which of the following scenarios illustrates the conservation of mass? A) Burning wood, B) Dissolving sugar in water, C) Both A and B, D) None of the above.

Answer 43

C) Both A and B

Question 44

What is the purpose of balancing a chemical equation?

Answer 44

To ensure that the number of atoms for each element is the same on both sides of the equation.

Question 45

True or False: In a balanced equation, the mass of the reactants must equal the mass of the products.

Answer 45

True

Question 46

Fill in the blank: The law of ______ states that matter cannot be created or destroyed in a chemical reaction.

Answer 46

conservation of mass

Question 47

Which of the following is a step in balancing chemical equations? A) Change the chemical formulas B) Adjust coefficients C) Add or remove elements

Answer 47

B) Adjust coefficients

Question 48

What is the balanced equation for the combustion of methane (CH4)?

Answer 48

CH4 + 2O2 → CO2 + 2H2O

Question 49

What is a solution in chemistry?

Answer 49

A homogeneous mixture of two or more substances.

Question 50

True or False: A solute is the substance that is dissolved in a solution.

Answer 50

True

Question 51

Fill in the blank: The substance that does the dissolving in a solution is called the ______.

Answer 51

solvent

Question 52

Which of the following is an example of a solvent? A) Salt B) Water C) Sugar D) Oil

Answer 52

B) Water

Question 53

What term describes the maximum amount of solute that can be dissolved in a solvent at a given temperature?

Answer 53

Solubility

Question 54

What is the primary purpose of distillation?

Answer 54

To separate components of a liquid mixture based on differences in their boiling points.

Question 55

True or False: Fractional distillation is used for separating mixtures with significantly different boiling points.

Answer 55

False

Question 56

Fill in the blank: In fractional distillation, a __________ column is used to increase the efficiency of separation.

Answer 56

fractionating

Question 57

What is the main difference between simple distillation and fractional distillation?

Answer 57

Simple distillation is used for mixtures with a large difference in boiling points, while fractional distillation is for those with closer boiling points.

Question 58

What type of mixtures is fractional distillation best suited for?

Answer 58

Complex mixtures with components that have boiling points close to each other.

Question 59

Multiple Choice: Which of the following is NOT a step in the distillation process? A) Heating, B) Cooling, C) Filtration, D) Condensation

Answer 59

C) Filtration

Question 60

What is the role of the condenser in the distillation process?

Answer 60

To cool and condense the vapor back into liquid form.

Question 61

True or False: Distillation can be used to purify water.

Answer 61

True

Question 62

Short Answer: Name one application of fractional distillation in the industry.

Answer 62

Petroleum refining.

Question 63

What is the significance of the boiling point in the distillation process?

Answer 63

It determines when a substance will vaporize and separate from the mixture.

Question 64

How does chromatography separate dyes

Answer 64

The more soluble ones dissolve in the mobile phase faster and therefore move more up the stationary phase

Question 65

How do you calculate the Rf value

Answer 65

Pigment distance ———————— Solvent distance It should always be less than one

Question 66

What is the purpose of the pencil line of origin

Answer 66

It acts as an insoluble line to measure from

Question 67

In chromatography, what type of molecule has the highest boiling point

Answer 67

Larger molecules