Chapter 05 Introduction to Solutions and Aqueous Dynamic Study Module Flashcards

Molarity is one of the most commonly used concentration units for solutions and is abbreviated as “M.”

Molarity is calculated by determining the number of moles of the solute, or the substance being dissolved, in 1 liter of solution. In other words, molarity is the number of moles/liter. This is summarized as follows:

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What is the molarity of a solution prepared from 29.2 grams of KNO ₃ in 425 milliliters of solutions?

• 0.0687 M KNO3
• 0.680 M KNO3
• 0.815 M KNO3
• 1.47 M KNO3

Molarity is one of the most commonly used concentration units for solutions and is abbreviated as “M.”

Molarity is calculated by determining the number of moles of the solute, or the substance being dissolved, in 1 liter of solution. In other words, molarity is the number of moles/liter. This is summarized as follows:

image attached

What is the molarity of a solution prepared from 19.4 g NaCl in 300.0 mL of solution?

• 1.11 M NaCl
• 0.0996 M NaCl
• 1.00 M NaCl
• 0.0647 M NaCl

Molarity is one of the most commonly used concentration units for solutions and is abbreviated as “M.”

Molarity is calculated by determining the number of moles of the solute, or the substance being dissolved, in 1 liter of solution. In other words, molarity is the number of moles/liter. This is summarized as follows:

image attached

Which solution has the highest molarity when 25.0 grams of the solute is dissolved in 250.0 milliliters of solution?

• LiCl
• Mg(OH)2
• NaCl
• AgNO3

The equation for a chemical reaction can be written in multiple ways. The most frequent method is to write molecular equations which show all substances as compounds or elements. Complete ionic and net ionic equations provide a more accurate representation of the reaction because they show the dissociation of substances in water. A complete ionic equation shows all aqueous substances as their component ions while a net ionic equation omits any spectator ions.

Select the net ionic equation for the reaction between HCl and NaOH.

• HCl(aq) + NaOH(aq) → H2O(l) + NaCl(aq)
• No reaction
• H+(aq) + OH−(aq) → H2O(l)
• H+(aq) + Cl−(aq) + Na+(aq) + OH−(aq) → H2O(l) + Cl−(aq) + Na+(aq)
• HCl(aq) + NaOH(aq) → H+(aq) + Cl−(aq) + Na+(aq) + OH−(aq)

What is the oxidation state of silicon in SiO ₃ ²⁻ ?

• −2
• 0
• +4
• +2
• −4

Precipitation reactions are the result of two aqueous substances reacting to form a solid product.

Identify the solid product formed, if any, from the reaction of (NH ₄ ) ₂ CO ₃ and Mg(NO ₃ ) ₂ .

• Mg(NO3)2
• NH4NO3
• No solid product formed.
• MgCO3
• (NH4)2CO3

What is the oxidation state of sulfur in Na ₂ S ₂ O ₃ ?

• +2
• −2
• +6
• +4

Molarity is one of the most commonly used concentration units for solutions and is abbreviated as “M.”

Molarity is calculated by determining the number of moles of the solute, or the substance being dissolved, in 1 liter of solution. In other words, molarity is the number of moles/liter. This is summarized as follows:

What is the molarity of a solution prepared from 10.0 grams of methanol (CH ₃ OH, density = 0.792 g/mL) with 125.0 milliliters of ethanol (CH ₃ CH ₂ OH)? Assume the volumes are additive.

• 0.800 M CH3OH
• 0.725 M CH3OH
• 2.27 M CH3OH
• 2.50 M CH3OH

What is the oxidation state of iodine in IO ₃ ⁻ ?

• −1
• +7
• +5
• +1

Strong electrolytes dissociate completely, weak electrolytes dissociate partially, and nonelectrolytes do not dissociate in water. The equilibrium arrow ( ⇌ ) is used to indicate compounds that partially dissociate.

Which equation best represent s the behavior of acetic acid, HC ₂H ₃ O ₂ , in water?

• HC2H3O2(l) ⇌ H+(aq) + C2H3O2−(aq)
• HC2H3O2(l) → H+(aq) + C2H3O2−(aq)
• HC2H3O2(l) ⇌ HC2H3O2(aq)
• HC2H3O2(l) → HC2H3O2(aq)

What volume of solution is prepared when 25.0 g of NaCl is added to enough water to make a 2.50 M NaCl solution?

• 0.585 L
• 0.935 L
• 1.07 L
• 0.171 L

Solution stoichiometry allows chemists to determine the volume of reactants or products involved in a chemical reaction when the chemical substances are dissolved in water. Instead of using mass to calculate the resulting amount of reactants or products, molarity and volume will be used to calculate the moles of substances.

A 35.00-mL sample of a 0.200 M solution of H ₃ PO ₄ reacts with excess NaOH. What mass of H ₂ O is produced in the reaction?

H ₃ PO ₄ ( aq ) + 3 NaOH( aq ) → Na ₃ PO ₄ ( aq ) + 3 H ₂ O( l )

• 0.126 g H2O
• 1.05 g H2O
• 0.0420 g H2O
• 0.378 g H2O

Electrolytes are substances that are able to conduct an electrical current as they form ions when they dissolve in water.

Strong electrolytes completely dissociate or break up into their ions. Soluble ionic solids, strong acids, and strong bases are all strong electrolytes.

Weak electrolytes partially dissociate or break up into their ions. Weak acids and weak bases are weak electrolytes.

Nonelectrolytes are unable to conduct an electrical current as they dissolve as molecules. Covalent compounds are nonelectrolytes.

Which of the following is a nonelectrolyte?

• Hydrochloric acid, HCl
• Ammonium chloride, NH4Cl
• Lactose, C12H22O11
• Water, H2O

What is the oxidation state of phosphorus in H ₃ PO ₄ ?

• +1
• +5
• +3
• +4

The equation for a chemical reaction can be written in multiple ways. The most frequent method is to write molecular equations which show all substances as compounds or elements. Complete ionic and net ionic equations provide a more accurate representation of the reaction because they show the dissociation of substances in water. A complete ionic equation shows all aqueous substances as their component ions while a net ionic equation omits any spectator ions.

Select the complete ionic equation for the reaction between AgNO ₃ and NaCl.

• Ag+(aq) + NO3−(aq) + Na+(aq) + Cl−(aq) → AgCl(s) +NO3-(aq) + Na+(aq)
• Ag+(aq) + Cl−(aq) → AgCl(s)
• AgNO3(aq) + NaCl(aq) → Ag+(aq) + NO3−(aq) + Na+(aq) + Cl−(aq)
• AgNO3(aq) + NaCl(aq) → AgCl(s) + NaNO3(aq)

Oxidation-reduction reactions are more commonly referred to as “redox reactions.” Redox reactions involve the simultaneous reduction and oxidation of two different chemicals due to the transfer of electrons.

Reduction occurs when an atom has gained electrons, resulting in a decrease in the oxidation state of that atom. The decrease in oxidation state occurs due to the gain of negatively charged electrons.

Oxidation occurs when an atom has lost electrons, resulting in an increase in the oxidation state of that atom. The increase in oxidation state occurs due to the loss of negatively charged electrons.

By comparing the oxidation states before and after a reaction occurs, you can determine if a substance was reduced or oxidized.

In the reaction shown below, which substance is reduced?

Mg ⁰ ( s ) + Zn ²⁺ ( aq ) → Mg ²⁺ ( aq ) + Zn ⁰ ( s )

• Mg0(s)
• Zn2+(aq)
• Mg2+(aq)
• Zn0(s)

Many ionic compounds, or salts, such as sodium chloride, are water-soluble. These compounds are referred to as soluble salts. When a soluble salt is placed in water, the ions separate or dissociate, creating a solution.

There are a number of ionic compounds that are not water-soluble. These compounds are referred to as insoluble salts, as they either stay as a solid, or form a solid, when placed in water.

Salts are soluble or insoluble based on interactions between the solute and the solvent. The solubility rules are arbitrary empirical rules based on a test such as ability to form a 0.1 M solution at 25 °C, or ability to dissolve one gram of solute in one liter of water. Many insoluble substances will dissolve less than the amount required to be considered soluble. We study these substances in chapter 18.

In using these solubility rules, for the salt to be considered water-soluble, the cation or anion must be able to dissolve in water.

The table of solubility rules provided here could differ from the table listed in your text. Using the table provided here, please answer the following question: Which of the following salts is insoluble in water?

• KNO3
• BaS
• CaSO4
• MgBr2

Electrolytes are substances that are able to conduct an electrical current, as they form ions when they dissolve in water.

Strong electrolytes completely dissociate or break up into their ions. Soluble ionic solids, strong acids, and strong bases are all strong electrolytes.

Weak electrolytes partially dissociate or break up into their ions. Weak acids and weak bases are weak electrolytes.

Nonelectrolytes are unable to conduct an electrical current, as they dissolve as molecules. Covalent compounds are nonelectrolytes.

Which of the following is a strong electrolyte?

• Potassium iodide, KI
• Acetic acid, CH3COOH
• Glucose, C6H12O6
• Methanol, CH3OH

Molarity is one of the most commonly used concentration units for solutions and is abbreviated as “M”.

Molarity is calculated by determining the number of moles of the solute, or the substance being dissolved, in 1 liter of solution. In other words, molarity is the number of moles/liter. This is summarized as follows:

What is the molarity of a solution containing 2.8 mol of LiCl and a volume of 5.00 × 10 ² mL?

• 1.4 M LiCl
• 5.6 M LiCl
• 0.17 M LiCl
• 6.0 M LiCl

Solution stoichiometry allows chemists to determine the volume of reactants or products involved in a chemical reaction when the chemical substances are dissolved in water. Instead of using mass to calculate the resulting amount of reactants or products, molarity and volume will be used to calculate the moles of substances.

Select the missing conversion factor for the following set of calculations:

Assume 0.38 L of a 2.8 M solution of magnesium chloride, MgCl ₂ , reacts with a 2.3 M solution of silver nitrate, AgNO ₃ , to produce silver chloride, AgCl, and magnesium nitrate, Mg(NO ₃ ) ₂ . The problem requires that you determine the volume of silver nitrate, AgNO ₃ , needed for the reaction to occur.

MgCl ₂ ( aq ) + 2 AgNO ₃ ( aq ) → 2 AgCl( s ) + Mg(NO ₃ ) ₂ ( aq )

What volume of 4.00 M HCl should be diluted to prepare 75.00 mL of a 1.25 M HNO ₃ solution?

• 2.40 mL
• 23.4 mL
• 42.7 mL
• 41.7 mL

Molarity is one of the most commonly used concentration units for solutions and is abbreviated as “M.”

Molarity is calculated by determining the number of moles of the solute, or the substance being dissolved, in 1 liter of solution. In other words, molarity is the number of moles/liter. This is summarized as follows:

What is the molarity of a solution having 1.4 mol of sodium chloride, NaCl, and a volume of 525 mL?

• 2.7 M NaCl
• 0.38 M NaCl
• 3.8 × 102 M NaCl
• 0.0027 M NaCl

What is the oxidation state of manganese in KMnO ₄ ?

• +5
• +3
• +7
• +1

Oxidation-reduction reactions are more commonly referred to as “redox reactions.” Redox reactions involve the simultaneous reduction and oxidation of two different chemicals due to the transfer of electrons.

A reducing agent causes another substance to be reduced. During the reaction, the reducing agent is oxidized. The electrons lost by the reducing agent are gained by another chemical, which is reduced.

An oxidizing agent causes another substance to be oxidized. During the reaction, the oxidizing agent is reduced.

Which substance is the oxidizing agent in the following reaction?

2 Au ³⁺ ( aq ) + 6 I ⁻ ( aq ) → 2 Au ⁰ ( s ) + 3 I ₂ ⁰ ( s )

• I20(s)
• Au3+(aq)
• I-(aq)
• Au0(s)

Oxidation-reduction reactions are more commonly referred to as “redox reactions.” Redox reactions involve the simultaneous reduction and oxidation of two different chemicals due to the transfer of electrons.

Reduction occurs when an atom has gained electrons, resulting in a decrease in the oxidation state of that atom. The decrease in oxidation state occurs due to the gain of negatively charged electrons.

Oxidation occurs when an atom has lost electrons, resulting in an increase in the oxidation state of that atom. The increase in oxidation state occurs due to the loss of negatively charged electrons.

By comparing the oxidation states before and after a reaction occurs, you can determine if a substance was reduced or oxidized.

In the reaction shown below, which substance is oxidized?

2 Fe ³⁺ ( aq ) + Sn ²⁺ ( aq ) → 2 Fe ²⁺ ( aq ) + Sn ⁴⁺ ( aq )

• Sn4+(aq)
• Sn2+(aq)
• Fe3+(aq)
• Fe2+(aq)

What is the final volume when 20.00 mL of 3.00 M NaCl solution is diluted to a final concentration of 0.100 M?

• 150. mL
• 167 mL
• 60.0 mL
• 600. mL

Solution stoichiometry allows chemists to determine the volume of reactants or products involved in a chemical reaction when the chemical substances are dissolved in water. Instead of using mass to calculate the resulting amount of reactants or products, molarity and volume will be used to calculate the moles of substances.

Select the missing conversion factor for the following set of calculations:

Assume 0.42 L of a 0.95 M solution of nickel(II) chloride, NiCl ₂ , reacts with a 1.5 M solution of sodium hydroxide, NaOH, to produce nickel(II) hydroxide, Ni(OH) ₂ , and sodium chloride, NaCl. The problem requires that you determine the volume of sodium hydroxide, NaOH, needed for the reaction to occur.

NiCl ₂ ( aq ) + 2 NaOH( aq ) → Ni(OH) ₂ ( s ) + 2 NaCl( aq )

What mass of KBr is present in 75.0 mL of 0.250 M KBr solution?

• 0.158 g
• 0.448 g
• 2.23 g
• 6.35 g

Solution stoichiometry allows chemists to determine the volume of reactants or products involved in a chemical reaction when the chemical substances are dissolved in water. Instead of using mass to calculate the resulting amount of reactants or products, molarity and volume will be used to calculate the moles of substances.

Select the missing conversion factor for the following set of calculations:

Assume 0.25 L of a 1.8 M solution of aluminum sulfate, Al ₂ (SO ₄ ) ₃ , reacts with a 4.2 M solution of sodium hydroxide, NaOH, to produce sodium sulfate, Na ₂ SO ₄ , and aluminum hydroxide, Al(OH) ₃ . The problem requires that you determine the volume of sodium hydroxide, NaOH, needed for the reaction to occur.

Al ₂ (SO ₄ ) ₃ ( aq ) + 6 NaOH( aq ) → 3 Na ₂ SO ₄ ( aq ) + 2 Al(OH) ₃ ( s )

Oxidation-reduction reactions are more commonly referred to as “redox reactions.” Redox reactions involve the simultaneous reduction and oxidation of two different chemicals due to the transfer of electrons.

Reduction occurs when an atom has gained electrons, resulting in a decrease in the oxidation state of that atom. The decrease in oxidation state occurs due to the gain of negatively charged electrons.

Oxidation occurs when an atom has lost electrons, resulting in an increase in the oxidation state of that atom. The increase in oxidation state occurs due to the loss of negatively charged electrons.

By comparing the oxidation states before and after a reaction occurs, you can determine if a substance was reduced or oxidized.

In the reaction shown below, which substance is oxidized?

Al ⁰ ( s ) + Cr ³⁺ ( aq ) → Al ³⁺ ( aq ) + Cr ⁰ ( s )

• Al3+(aq)
• Cr3+(aq)
• Cr0(s)
• Al0(s)

Oxidation-reduction reactions are more commonly referred to as “redox reactions.” Redox reactions involve the simultaneous reduction and oxidation of two different chemicals due to the transfer of electrons.

A reducing agent causes another substance to be reduced. During the reaction, the reducing agent is oxidized. The electrons lost by the reducing agent are gained by another chemical, which is reduced.

An oxidizing agent causes another substance to be oxidized. During the reaction, the oxidizing agent is reduced.

Which substance is the reducing agent in the following reaction?

Fe ₂ O ₃ ( s ) + 3 CO( g ) → 2 Fe( s ) + 3 CO ₂ ( g )

• CO(g)
• Fe2O3(s)
• CO2(g)
• Fe(s)

A 25.00-mL sample of 6.00 M HCl solution is diluted to a new volume of 85.00 mL. What is the concentration of the dilute solution?

• 1.76 M
• 0.568 M
• 2.82 M
• 2.04 M

Oxidation-reduction reactions are more commonly referred to as “redox reactions.” Redox reactions involve the simultaneous reduction and oxidation of two different chemicals due to the transfer of electrons.

Reduction occurs when an atom has gained electrons, resulting in a decrease in the oxidation state of that atom. The decrease in oxidation state occurs due to the gain of negatively charged electrons.

Oxidation occurs when an atom has lost electrons, resulting in an increase in the oxidation state of that atom. The increase in oxidation state occurs due to the loss of negatively charged electrons.

By comparing the oxidation states before and after a reaction occurs, you can determine if a substance was reduced or oxidized.

In the reaction shown below, which substance is oxidized?

Ca ⁰ ( s ) + Pb ²⁺ ( aq ) → Ca ²⁺ ( aq ) + Pb ⁰ ( s )

• Ca2+(aq)
• Pb2+(aq)
• Ca0(s)
• Pb0(s)