Unit 3 - Clemson Schroeder CH-1010 Flashcards

What is the charge on group 2 metals and how does it affect their reaction with phosphorus?

Group 2 metals have a +2 charge and react with phosphorus by forming compounds that balance the charges, for example, Mg with +2 and P with -3 forms a stable compound.

How do you combine reactants in a double displacement reaction such as silver nitrate and potassium chloride?

Combine the cation from one reactant with the anion from the other to form compounds; for example, silver nitrate and potassium chloride form silver chloride, which can be determined using solubility rules.

What ions are considered spectator ions in a reaction between AgNO3 and KCl?

Nitrate and potassium ions are spectator ions as they do not participate in the formation of the precipitate and remain in solution as ions.

How do you determine if an acid like HBr dissociates completely in water?

HBr is a weak acid and does not dissociate significantly in water; the strength of acids can predict their dissociation.

What criteria are used to classify a reaction as a redox reaction?

A reaction is classified as redox if there is a change in oxidation states of the elements, indicating electron transfer as in the oxidation of Zn from 0 to +2.

How are oxidation numbers assigned in compounds?

Oxidation numbers are assigned based on standard states and balancing charges where the sum of oxidation numbers in a neutral compound must equal zero.

How do you calculate the change in enthalpy (Delta H) for a chemical reaction?

Calculate Delta H by using bond dissociation energies: break bonds (endothermic, positive value) and form bonds (exothermic, negative value), then sum these energies.

When predicting reaction products, how do solubility rules assist in determining the formation of solids?

Solubility rules help determine which combinations of ions will form insoluble compounds (solids) in solution, such as silver chloride being insoluble.

In redox reactions, how do you identify the substance being oxidized and reduced?

Identify substances being oxidized and reduced by changes in oxidation numbers: the element whose oxidation number increases is oxidized, and the one whose number decreases is reduced.

What is the significance of identifying spectator ions in chemical reactions?

Identifying spectator ions is important to simplify equations to net ionic forms, highlighting only the ions involved in forming the precipitate or product.

How do you predict whether a substance will be a strong or weak electrolyte?

Predict based on dissociation in solution: strong electrolytes (like strong acids) dissociate completely, while weak electrolytes (like weak acids) do not.

Why are solubility rules important in predicting precipitation reactions?

Solubility rules predict which ions form insoluble compounds in aqueous solutions, crucial for predicting if a precipitation reaction will occur.

Explain how acid-base reactions result in the formation of salt and water.

In acid-base reactions, an acid reacts with a base to form water and a salt, as the hydroxide ions combine with hydrogen ions to form water.

What steps should you follow when using bond dissociation energies to calculate reaction enthalpies?

Identify all bonds broken (endothermic) and formed (exothermic), use bond energies to calculate total enthalpy change, and sum these energies for total reaction enthalpy.

How do changes in oxidation number indicate a redox reaction?

Changes in oxidation numbers indicate a redox reaction; the element with an increased oxidation number is oxidized, while one with decreased is reduced.

What are the rules for assigning oxidation numbers to elements in their standard states?

Elements in their standard states are assigned an oxidation number of 0.

How can Hess's Law be used to calculate the enthalpy change of a reaction?

Hess's Law calculates reaction enthalpy by manipulating algebraic equations of known reactions to derive the enthalpy change of the target reaction.

What factors influence a substance's specific heat capacity?

A substance's specific heat capacity is influenced by its molecular structure and phase, which affect its ability to retain and transfer heat.

Define exothermic and endothermic reactions in thermochemistry.

Exothermic reactions release heat to the surroundings, while endothermic reactions absorb heat from the surroundings.

What is the thermodynamic standard state, and why is it significant?

The thermodynamic standard state is the most stable form of a substance under standard conditions. It is used for accurate calculations of thermochemical data like enthalpies.

How do you use the standard heat of formation to calculate reaction enthalpy?

The standard heat of formation calculations involve using tabulated values for standard states to find the total enthalpy change by summing the energies of products and reactants.

What common mistakes should be avoided when solving stoichiometry problems?

Common stoichiometry mistakes include incorrect variable entry, improper balancing of equations, and misunderstanding of mole-to-mole ratios.

How can bond dissociation energy be used to approximate ΔH for a reaction?

Bond dissociation energy can approximate ΔH by summing the energies required to break bonds in reactants minus the energy released when forming bonds in products.

What is the significance of a substance's specific heat in terms of energy retention?

A high specific heat means the substance can absorb more heat without significant changes in temperature, influencing thermal stability and heat retention.

How do you manipulate reaction equations using Hess's Law to derive ΔH?

With Hess's Law, calculate ΔH by rearranging and combining known reactions to cancel unwanted substances and derive the target reaction's enthalpy.

What are the designated charges of elements in compounds when assigning oxidation numbers?

Elements in compounds usually have oxidation numbers equal to their charge, reflecting gains or losses of electrons in bonding.

Can you explain the role of a periodic table in stoichiometry and thermochemistry exam questions?

The periodic table helps identify elements' properties such as atomic mass, which is necessary for calculating moles, balancing equations, and determining reaction energetics.

What is coffee cup calorimetry and how does it relate to ΔH?

Coffee cup calorimetry measures the heat of reaction at constant pressure, providing the ΔH, indicated by temperature change (warm for exothermic, cold for endothermic).

How should one approach old exams for effective exam preparation in stoichiometry?

Map practice questions to old exam questions to identify patterns, recurring themes, and key concepts likely to be assessed in current exams.

In what situations can standard formation reaction tables aid in calculating enthalpies?

Standard formation reaction tables are useful when the overall reaction can be broken down into component formation reactions from elemental states.

What is the significance of 'squeakyometry' in Chapter 9?

Squeakyometry, likely a colloquial term for stoichiometry, involves the calculations of reactants and products in chemical reactions, important for exam preparation.

How do exothermic reactions impact system and surroundings energy transfer?

In exothermic reactions, the system loses energy to the surroundings, typically releasing heat.

Compare and contrast specific heat capacity and heat capacity concepts.

Specific heat capacity refers to the heat required to change a unit mass of a substance by one degree Celsius, while heat capacity is the heat required to change the temperature of a specific amount of substance.

How can grading errors affect the learning process?

Grading errors can lead to misunderstandings of key concepts if not corrected, underscoring the importance of accuracy in assessments.

Explain the role of a calorimeter in energy measurement experiments.

A calorimeter is used to measure the heat transfer during a chemical reaction, helping to determine the energy changes involved.

What is the relationship between work done by a system and volume change?

Work done by the system is related to volume change by the equation Work = -PΔV, where expansion denotes work done on surroundings, and compression indicates work done on the system.

Why are state functions like energy considered path-independent?

State functions depend only on the initial and final states, not the path taken to get there, similar to climbing a mountain where different paths lead to the same summit.

Describe the importance of heat, work, and energy in chemical reaction studies.

Heat, work, and energy are crucial for understanding how energy is transferred and transformed during chemical reactions, impacting reaction dynamics and system changes.

What problem-solving strategies are effective for understanding limiting reactants?

Effective strategies include setting up balanced equations, determining the moles of reactants, and calculating which reactant is used up first in the reaction context.

How does the example of rust reaction with hand warmers illustrate thermal energy concepts?

The rust reaction in hand warmers is exothermic, demonstrating how chemical reactions can transfer thermal energy to surroundings, such as warming hands.

What errors are commonly seen in grading energy-related problems and how to avoid them?

Common errors include miscalculating path-independent variables or neglecting units. These can be avoided by double-checking calculations and adhering to dimensional analysis.

How do you convert work from atmospheres to joules?

To convert work from atm to joules, use the conversion factor: 1 L·atm = 101.3 Joules.

What are the implications of temperature changes on heat capacity calculations?

Temperature changes impact the amount of heat required or released in reactions, influencing calculations with equations like Q = C × mass × ΔT.

How does the concept of limiting reactants relate to stoichiometry problems?

Limiting reactants determine the maximum yield in a reaction, making it critical to stoichiometry problems where reactant quantities dictate product formation.

What strategies are suggested for effective exam preparation based on class notes?

Recommended strategies include reviewing specific chapters, utilizing practice exams, and focusing on correcting misunderstandings before testing.

What distinguishes a strong acid from a weak acid in their behavior in water?

Strong acids completely dissociate in water, whereas weak acids only partially dissociate.

Why is it important to recognize strong electrolytes when predicting chemical reactions?

Strong electrolytes completely dissociate into ions in water, which can affect the formation of products, especially in precipitation and acid-base reactions.

What steps are involved in writing a balanced net ionic equation from a molecular equation?

Predict the products, balance the equation, identify and cancel out spectator ions to achieve the net ionic equation.

How can you determine if an ionic compound is soluble in water based on solubility rules?

Consult the solubility rules table to check if the compound is above the solubility line (soluble) or below it (insoluble).

Describe the process and result of a precipitation reaction using lead nitrate and iodide as an example.

Lead nitrate reacts with potassium iodide to form a precipitate of lead iodide, which is an insoluble compound, and a soluble nitrate salt.

How do strong bases differ in their dissociation process compared to weak bases?

Strong bases, typically metal hydroxides, dissociate completely in water to release hydroxide ions.

What is the mnemonic OIL RIG used for in chemistry, and what does it stand for?

OIL RIG is used to remember the principles of oxidation and reduction: Oxidation Is Loss (of electrons), Reduction Is Gain (of electrons).

In an acid-base reaction, what is typically produced when a strong acid reacts with a strong base?

The reaction usually produces water and a salt.

Explain the significance of oxidation numbers in determining redox reactions.

Oxidation numbers help identify which elements are oxidized or reduced by indicating whether they gain or lose electrons.

Why is the law of conservation of energy crucial in the study of thermodynamics?

It states that energy cannot be created or destroyed but can only be transferred or transformed, ensuring energy balance in reactions.

What are the system and surroundings in thermodynamics, and how do interactions between them occur?

The system is the part of the universe under study, while the surroundings are everything else. Interactions occur as energy (heat and work) is transferred between them.

In thermodynamics, why are positive and negative signs important for interpreting energy transfer?

A positive sign indicates energy is gained by the system, while a negative sign indicates energy is lost, crucial for understanding the system's behavior.

What is the role of spectator ions in chemical equations, and how are they treated in net ionic equations?

Spectator ions do not participate in the chemical reaction and are canceled out or removed to simplify the net ionic equation.

How would you use the solubility rules table to predict if silver sulfate and sodium chloride would react in aqueous solution?

Check the solubility of both compounds using the table. Silver sulfate may precipitate if it's insoluble, while sodium chloride, being soluble, dissociates completely.

What is a real-world example of a redox reaction and the specific changes in electron transfer?

Rust formation is a redox reaction where iron loses electrons (oxidation) and oxygen gains electrons (reduction).

What is the main purpose of balancing a chemical equation?

To ensure there are equal numbers of each element on both sides of the equation, maintaining the law of conservation of mass.

How do you identify a limiting reactant in a chemical reaction?

Calculate the amount of product each reactant can produce, and the reactant that produces the least amount of product is the limiting reactant.

What are the basic solubility rules for halogen series (chlorine, bromine, and iodine)?

Chlorine, bromine, and iodine compounds are generally soluble except when combined with silver (Ag).

Explain the importance of molar mass in stoichiometry.

Molar mass allows conversion between the mass of a substance and the number of moles, which is essential for stoichiometric calculations in chemical reactions.

What are the 12 polyatomic ions you need to know for advanced stoichiometry?

This specific set of ions wasn't detailed in the notes provided. Generally, it includes ions like sulfate (SO₄²⁻), nitrate (NO₃⁻), and ammonium (NH₄⁺) among others.

State the dilution equation and explain its components.

The dilution equation is M₁V₁ = M₂V₂, where M refers to molarity and V refers to volume; it calculates how concentration changes when a solution is diluted.

Describe the difference between strong and weak electrolytes.

Strong electrolytes dissociate completely in solution, such as strong acids and bases, whereas weak electrolytes only partly dissociate.

What is a net ionic equation and its purpose?

A net ionic equation shows only the ions and molecules directly involved in a chemical reaction, omitting spectator ions to highlight the actual chemical change.

Why are Group 1 and ammonium compounds always considered soluble?

These compounds universally dissolve in water under standard conditions due to their ionic nature and interaction with polar water molecules.

How do strong acids and bases behave in solution?

Strong acids and bases dissociate completely in aqueous solutions, resulting in increased conductivity due to the free ions.

What is the role of molarity in stoichiometric calculations involving solutions?

Molarity, defined as moles of solute per liter of solution, helps determine the concentration and is crucial for calculations related to solution reactions.

Explain the concept of theoretical yield in stoichiometry.

Theoretical yield is the maximum amount of product that can be generated from a given amount of reactants under perfect conditions.

How are molecular equations different from ionic equations?

Molecular equations present compounds as whole formulas, while ionic equations break them into their constituent ions to show all species present in the reaction.

What concept is emphasized in Quiz 13 related to stoichiometry?

Quiz 13 emphasizes the application of stoichiometry concepts, particularly balancing equations, identifying limiting reactants, and using conversion factors.

Discuss the solubility rules for compounds that do not abide by the general solubility rules.

Compounds that contain lead (Pb²⁺), mercury (Hg₂²⁺), and barium (Ba²⁺) are exceptions in some cases; these usually form precipitates and remain insoluble.

What is the primary purpose of balancing chemical equations?

To ensure that there are equal numbers of each type of atom on both sides of the equation, maintaining the law of conservation of mass.

What is direct balancing by inspection?

A method used in balancing chemical equations where one adjusts the coefficients directly to balance the number of atoms in reactants and products.

In stoichiometry, how is the mole used to relate reactants and products?

The mole is used to convert between mass and number of particles and to use the ratio of moles in the balanced equation to calculate amounts of reactants and products.

Why must chemical equations be balanced before performing stoichiometry calculations?

Balancing equations ensures that stoichiometry calculations are accurate, as they rely on the mole ratios provided by the balanced equation.

What is a limiting reactant and why is it important?

The limiting reactant is the substance that is completely consumed first, limiting the amount of product formed in a chemical reaction.

How does one calculate the theoretical yield of a reaction?

Theoretical yield is calculated by using stoichiometry to find the maximum amount of product that can be formed from the limiting reactant.

What is the relationship between atomic mass and molar mass?

Atomic mass is the mass of a single atom, while molar mass is the mass of one mole of atoms (or molecules) expressed in grams.

Explain how to calculate percent yield.

Percent yield is calculated by dividing the actual yield by the theoretical yield and multiplying by 100%.

Why are diatomic molecules important when calculating molar mass?

Diatomic molecules, such as O2 or H2, must be considered as two atoms, impacting the calculated molar mass used in stoichiometry.

What is the significance of excess reactants in a chemical reaction?

Excess reactants are the substances left over after the limiting reactant is completely consumed; they do not limit production but can affect cost-effectiveness.

How can stoichiometry be applied in industrial chemical reactions?

Stoichiometry ensures efficient use of reactants, minimization of waste, and cost-effectiveness in producing desired chemical products in industry.

What approach can be used to find the mass of a second reactant needed if the mass of another reactant is given?

Use the balanced equation to determine the mole ratio between the reactants, then convert the given mass to moles and apply the ratio to find the needed mass.

Why is it essential to regularly practice stoichiometry problems?

Regular practice helps build familiarity and confidence, ensuring a deeper understanding and ability to apply stoichiometric principles in varied situations.

Describe a real-world scenario where stoichiometry is crucial.

In pharmaceuticals, stoichiometry is crucial in determining drug compositions and reactions to ensure both safety and efficacy.

How can economic considerations influence the use of stoichiometry in industry?

Proper stoichiometry minimizes the waste of expensive chemicals and can optimize processes for better resource utilization and cost efficiency.

How is the final grade calculated if Canvas is not used for final grade calculation?

Grades are calculated based on skills, with a specific distribution of 15% for each named component and a total of 45% of the points divided to achieve a complete score.

How does electronegativity relate to the polarity of bonds?

Electronegativity differences determine bond polarity, with more polar bonds having greater electronegativity differences.

Which atom is considered least electronegative in bond discussions?

Hydrogen is considered the least electronegative.

What is the implication of a negative charge on resonance structures?

The negative charge should be placed on more electronegative atoms.

What are the factors affecting lattice energy?

Lattice energy is influenced by the charge and radius of ions involved.

In molecular structures, how is the central atom determined?

Central atoms can be determined by examining the compound's structure and electronegativity.

What type of geometric shape is formed by the compound SF6?

SF6 forms an octahedral geometry.

Differentiate between hydrogen bonds and dipole interactions in terms of strength and characteristics.

Hydrogen bonds are usually stronger than dipole interactions and involve hydrogen and electronegative atoms like nitrogen, oxygen, or fluorine.

Why is chlorine considered highly electronegative among the halogens?

Chlorine has a higher ability to attract electrons within a bond compared to other halogens.

Describe the stoichiometric process of converting from grams to moles.

Stoichiometry involves calculating the number of moles from a given mass by using the molecular weight as a conversion factor.