Chemistry Exam

An oxygen tank is being filled at a hospital for asthma patients. As the tank is being filled, what is true about the gas in the tank?

(b) The pressure of the gas in the tank will increase. As more gas is pumped into the tank, there will be more collisions of gas particles and so more pressure.

CH3(CH2)10CH3 reacts with another substance to form carbon dioxide and water. This is an example of

(b) combustion

C3H8 + 5O2 →→3CO2 + 4H2O What is this type of reaction called?

(b) combustion reaction

Which statements about limiting and excess reagents are true? Select all that apply. A. Any reactant that is not used up during the chemical reaction is called a limiting reagent. B. Any reactant that is not used up during the chemical reaction is called a excess reagent. C. The reactant that determines how much product can be formed during a chemical reaction is called the limiting reagent. D. The reactant that determines how much product can be formed during a chemical reaction is called the excess reagent. E. The chemical reaction continues after the limiting reagent is used up because some amount of the other reactant remains. F. The chemical reaction stops after the limiting reagent is used up even though some amount of the other reactant remains.

(b, c, f) Any reactant that is not used up during the chemical reaction is called a excess reagent, The reactant that determines how much product can be formed during a chemical reaction is called the limiting reagent, The chemical reaction stops after the limiting reagent is used up even though some amount of the other reactant remains.

Which mole ratios are possible for this equation? Select all that apply. 3N2H4 →→ 4NH3 + N2 A. 2 mol N2/3 mol N2H4 B. 1 mol N2/3 mol N2H4 C. 3 mol NH3/4 mol N2H4 D. 4 mol NH3/3 mol N2H4 E. 3 mol NH3/2 mol N2

(b, d) 1 mol N2/3 mol N2H4, 4 mol NH3/3 mol N2H4

Select the gas law and explanation that best describes the phenomenon that the traveler experienced on the plane.

(c) Boyle's law: as the pressure of a gas increases, the volume decreases

The organic compound 2,2-dimethylbutane is sometimes used as a component of motor and aviation fuel. Which molecular formula represents the condensed structural formula for 2,2-dimethylbutane?

(c) CH3C(CH3)2CH2CH3

Pick one distinguishing feature of the chemical reaction shown in the image.

(c) One reactant and two products are involved in a decomposition reaction.

The images show the state of a gas in two containers of different volumes. Select the best statement that describes the number of collisions among the gas molecules in the containers.

(c) The number of collisions among the gas molecules is greater in container 2 than in container 1 because the volume is smaller.

Death Valley in California is 86 m below sea level. Select the option that describes the partial pressure of oxygen in Death Valley.

(c) The partial pressure will be higher than at sea level at all times.

A large amount of heat energy was supplied during a combustion reaction. Which of the following symbols should be used in the chemical equation to represent the heat supplied during the reaction?

(c) a triangle placed above the yield sign

A carbon atom has four valence electrons and is able to combine with itself and with other elements, including hydrogen and oxygen, among others. Carbon compounds are generally classified as organic. Select the compound that is not an organic compound.

(c) carbon dioxide

The skeleton chemical equation for the reaction between zinc metal and hydrochloric acid is shown. Zn + HCl →→ ZnCl2 + H2 What should be done to balance the equation?

(c) put a coefficient 2 in front of HCl

A student placed a small piece of magnesium ribbon in a conical flask and added 60 mL hydrochloric acid. The student observed that when the hydrochloric acid came into contact with the magnesium ribbon, bubbles formed, indicating the release of hydrogen gas. The magnesium dissolved and magnesium chloride solution formed. Based on the student's observations, which type of reaction occurred?

(c) single replacement reaction

The components of a buffer system help to keep the pH at equilibrium

(c) when H+ or OH- are added to the system.

Acids and bases share some common properties. Which of the properties mentioned below do acids and bases share? Select all that apply. A. Both acids and bases have a sour taste. B. Both acids and bases are slippery to the touch. C. Both acids and bases can conduct electricity in aqueous solutions. D. Both acids and bases affect indicators such as litmus paper.

(c, d) Both acids and bases can conduct electricity in aqueous solutions, Both acids and bases affect indicators such as litmus paper.

Bromine water, which is reddish brown in color, is decolorized when added to certain hydrocarbons. Which statement best describes the hydrocarbons that will decolorize bromine water?

(d) Alkenes and alkynes will decolorize bromine water because they are both unsaturated hydrocarbons.

Proteins are made from a chain of amino acids that fold into complex shapes to perform various cellular functions. Proteins can also be denatured, which can be reversible or irreversible. Which of the following is the best example of denaturation?

(d) Intermolecular forces are disrupted through the addition of heat.

Which statement correctly describes the difference in energy between molecules of saturated and unsaturated fatty acids? Assume that an equivalent number of molecules that also have the same chain length are being compared.

(d) Saturated fat molecules have more energy because the two extra carbon-hydrogen bonds have more energy than one carbon-carbon double bond.

The figure shows the reaction of acetic acid in water. Identify the conjugate acid of water in this reaction.

(d) hydronium ion

The number of ___________ atoms in the parent chain determines the prefix of a hydrocarbon. The suffix is determined by the presence of a specific type of ____________.

carbon, bond

All chemical equations adhere to the law of conservation of mass. According to this law, the number of atoms on the reactant side __________ the number of atoms on the product side. This means that the total mass of reactants __________ the total mass of products. The total amount of moles in the reactants compared to the total amount of moles in the products of a reaction ___________ since some atoms may rearrange to form new products.

is the same as, is the same as, may vary

The production of an alcohol from a halocarbon is a(n) __________ reaction in which the halogen group on a halocarbon is replaced by a __________. Unsaturated hydrocarbons, however, readily undergo __________ reactions to form saturated compounds.

substitution, hydroxide ion, addition

Which of the following compounds would most likely be the reactants in a combustion reaction? A. sulfuric acid and water B. oxygen and a hydrocarbon C. oxygen and carbon dioxide D. carbon dioxide and a hydrocarbon

(b) oxygen and a hydrocarbon

Choose the words to finish the sentence.2NO + Cl2 →→ 2NOCl One possible mole ratio for this equation is __________ /__________

2 mol NO/2 mol NOCl

The balanced equation for the decomposition of HCl is:

(a) 2HCl →→ H2 + Cl2

Based on the understanding of the mechanism of a single displacement reaction, which of the following chemical equations represent a single displacement reaction? Select all that apply. A. NaCl + AgNO3 → NaNO3 + AgCl B. Cu + AgNO3 → CuNO3 + Ag C. 2NaBr + Cl2 → 2NaCl + Br2 D. F2 + 2NaBr → 2NaF + Br2 E. KOH + HCl → KCl + H2O

b, c, d

Consider the following organic reaction: C4H9Cl + KOH ⟶ C4H9OH + KCl What type of reaction is this?

(d) Substitution, because an atom or group of atoms replaces another atom or group.

The neutralization of __________ with __________ results in the formation of potassium sulfate.

potassium hydroxide, sulfuric acid

A hot-air balloon rises in the air and does not change in shape as long as the __________ caused by collisions of molecules inside is equal to that outside the balloon. If more gas is pumped into the balloon, the number of collisions of gas molecules inside will __________. . To counter this, the balloon will __________ in size.

pressure, increase, expand

H2 + O2 →→ H2O is an example of a skeleton equation. The chemicals on the left side of the arrow are present before the reaction takes place and are called __________, and the chemicals on the right side of the arrow are formed after the reaction has occurred and are called __________.

reactants, products

Drag the words to complete the sentence. Observe the reaction. N2(g) + 3H2(g) ⟶ 2NH3(g) In this reaction, __________ mole(s) of H2 is/are proportional with ___________ mole(s) of NH3.

three, two

Fatty acids with the cis and trans configurations are __________ hydrocarbons because of the double bond present. However, they are __________ isomers and have different properties. __________ isomers are a pair of _________ carbons that are mirror images.

unsaturated, geometric, optical, asymmetrical

How do greenhouse gases, such as carbon dioxide and water vapor, influence Earth's climate? Select all that apply. A. Greenhouse gases block solar radiation from entering Earth's atmosphere. B. Greenhouse gases allow solar radiation to pass through Earth's atmosphere. C. Greenhouse gases create infrared radiation, allowing heat to escape into space. D. Greenhouse gases absorb infrared radiation, trapping heat in Earth's atmosphere.

(b, d) Greenhouse gases allow solar radiation to pass through Earth's atmosphere, Greenhouse gases absorb infrared radiation, trapping heat in Earth's atmosphere.

A shipment of chemicals arrived at a manufacturing building to stock the various departments. The chemicals must be sent to the proper locations within the building based on their use. Alkanes will be used as fuels. Alkenes will be used in the production of plastics. Alkynes will be used to produce organic solvents to degrease machines. Which image(s) and/or description(s) match the chemical that will be used to degrease machines? Select all that apply.

(b, d) model, a chemical with a triple bond in the parent chain

Fill in the blanks with coefficients to balance the chemical equation shown: _____ Al + _____ CuCl2 ---> _____ Cu + _____ AlCl3

2, 3, 3, 2

The chemical reaction shows the conversion of n-hexane to cyclohexane and benzene products. To form cyclohexane, a molecule of hexane loses _____ hydrogen atoms to satisfy the covalency of carbon. A molecule of cyclohexane loses _____ hydrogen atoms to form benzene.

2, 6

In any chemical reaction, no new atoms are created or destroyed, but are simply rearranged. Therefore, when balancing equations, the atoms in the product are the same atoms in the reactants. In this reaction, nitrogen reacts with hydrogen to form ammonia. From the list, label this chemical reaction.

N2, 3H2, 2NH3

Two different hydrocarbons have the chemical formulas C4H8 and C3H8, respectively. The molecular structure of C4H8 is a hydrocarbon ring, and the molecular structure of C3H8 consists of a straight chain.Choose the correct terms to complete the sentences. The hydrocarbon with the formula C4H8 is ___________, and C3H8 is __________. Between these two hydrocarbons, the molecule with the __________ structure will have a higher boiling point.

cyclobutane, propane, hydrocarbon ring

Select the correct balanced equation to describe the reaction of iron (III) chloride with sodium sulfate to form iron (III) sulfate and sodium chloride.

(a) 2FeCl3 + 3Na2SO4→→ Fe2(SO4)3 + 6NaCl

Which of the following reactions represents the combustion of propane (C3H8)?

(a) C3H8 + 5O2 →→ 3CO2 + 4H2O

Propanoic acid (CH3CH2COOH) dissolves in water to produce two products. Select the equation that best represents the reaction between propanoic acid and water.

(a) CH3CH2COOH + H2O ⇋ CH3CH2COO⁻ + H3O⁺

Hydrogen and carbon atoms combine to form hydrocarbons. Two line-angle formulas of hydrocarbons are shown. The boiling points of the two hydrocarbons, in random order, are 150.8°C and 98.4°C. Which answer best matches the structure of A and B to their boiling points and why?

(a) Molecule B has a boiling point of 150.8°C, and molecule A has a boiling point of 98.4°C, because B has a larger surface area, so the intermolecular forces are stronger.

What are the products of the self-ionization of water?

(a) OH- and H3O+

Mixing a strong acid with a strong base produces a neutralization reaction with which of the following products?

(a) salt and water

This chemical reaction follows the law of conservation of mass. Mg(OH)2(aq) + 2HCl(aq) ⟶ 2H2O(l) + MgCl2(aq) Which of the statements are true? Select all that apply. A. In this reaction, atoms rearrange to form new molecules. B. Atoms are created and destroyed in this chemical reaction. C. Atoms are neither created nor destroyed in this chemical reaction. D. In this reaction, atoms do not rearrange to form new molecules. E. In this reaction, the number of atoms of the reactants is the same as the number of atoms of the products. F. In this reaction, the number of atoms of the reactants is different than the number of atoms of the products.

(a, c, e) In this reaction, atoms rearrange to form new molecules, Atoms are neither created nor destroyed in this chemical reaction, In this reaction, the number of atoms of the reactants is the same as the number of atoms of the products.

Bases dissolve in water. Determine which equations represent bases in water. Select all that apply. A. NH3 + H2O ⇌⇌ NH4⁺ + OH⁻ B. NH3 + H2O ⇌⇌ NH2 + H3O⁺ C. C5H5N + H2O ⇌⇌ C5H4N⁻ + H3O⁺ D. C5H5N + H2O ⇌⇌ C5H5NH⁺ + OH⁻

(a,d) NH3 + H2O ⇌⇌ NH4⁺ + OH⁻, C5H5N + H2O ⇌⇌ C5H5NH⁺ + OH⁻

The balanced equation for the decomposition of potassium chlorate to form potassium chloride and oxygen is

(b) 2KClO3 →→ 2KCl + 3O2

What is the mol ratio of sodium carbonate to aluminum chloride in this reaction? 2AlCl3(aq) + 3Na2CO3(aq) → 6NaCl(aq) + Al2(CO3)3(s)

(b) 3:2

The balanced chemical equation for the reaction of magnesium with hydrochloric acid is as follows: Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g) In order to produce 5 moles of H2(g), how many moles of Mg and HCl are needed?

(b) 5 moles of Mg and 10 moles of HCl

The given addition reaction takes place at 100°C in the presence of acidulated water: CH3CH = CHCH3 + H2O ⟶ What is the condensed structural formula of the expected product?

(b) CH3CH2CH(OH)CH3

What happens to gas particles within a closed container when the temperature increases?

(b) The kinetic energy of the particles increases.

Observe images B and C. What might be the reason why fatty acids do not mix or dissolve in water?

(b) The presence of long hydrocarbon chains makes them hydrophobic.

Fill in the blanks with coefficients to balance the chemical equation shown: _____ H2S + ______ O2 ---> _____ SO2 + _____ H2O

2, 3, 2, 2

Choose the correct terms to complete the sentence. According to Boyle's law, if volume is divided in half, pressure will __________ , so long as the number of particles in a gas __________.

double, remain constant

In the __________ reaction between CuSO4 and NaOH, CuSO4 is a __________ and Na2SO4 is a __________. The number "2" in the formula 2NaOH is a __________.

endothermic, reactant, product, coefficient

Choose the correct word(s) in each case to correctly complete the paragraph about the properties of gases. Gas particles will __________ to occupy the available space in the container. The large amount of space between gas particles also means that the volume of the gas can be made to decrease if the pressure on the gas is __________ . This will lead to ___________ collisions between particles. Decreasing the gas volume in this way is a measure of the gas's __________.

expand, increased, more, compressibility

Nucleotides form __________ in sets known as base pairs. This structure holds together the __________, which is folded into chromosomes.

hydrogen bonds, double helix

Phospholipid molecules are found in cell membranes. Their __________ ends are attracted to water. Their __________ ends repel water. This double layer enables the cell to form a __________ to keep the contents of the cell in while allowing certain molecules to move into and out of the cell.

hydrophilic, hydrophobic, barrier

The energy found in the food you eat is measured in __________. Monomers and polymers of aldehydes and ketones that have numerous additional hydroxyl groups attached are called __________. They are used to ____________________. Compounds that contain an amino group and a carboxyl group are called __________. Water-insoluble compounds like oils and fats are called __________.If they have _________ chains, then they are liquids or oils. Monomers that are made from a phosphate group, a five-carbon sugar, and a nitrogen base are called _________.

kilocalories, carbohydrates, store energy in cells, amino acids, lipids, unsaturated, nucleotides