Bonding, Chemical Reactions, and Nomenclature Reactions in Aqueous Solutions Measurements, Units, and the Mole Stiochiometry Energy and Thermochemistry

Question What is the name for HNO 3 ?

Answer 1 – 10 Nitric Acid

Question What type of bond represents a sea of electrons?

Answer 1 – 20 Metallic Bonding

Question The electrons in a nonpolar covalent bond are: a)Unequally shared between atoms b)Just exist and do not interact c)Shared equally between atoms

Answer 1 – 30 C) Shared equally between atoms

Question Balance this equation: __ HF(aq)+__Ca(OH) 2 (aq) → __ H 2 O(aq)+__ CaF 2 (aq)

Answer 1 – 40 2 HF(aq)+Ca(OH) 2 (aq) → 2 H 2 O(aq)+ CaF 2 (aq)

Question Name 6 polyatomic ions

Answer 1 – 50 NH 4 + NO 2- NO 3- SO 3 2- OH - CN -

Question What are the products in this double displacement reaction? NaOH (aq) + MgCl 2 (aq) → ?? 2. Does a precipitate form?

Answer 2 – NaOH (aq) + MgCl 2 (aq) → 2NaCl + Mg(OH) 2 2.Yes! Mg 2+ (aq) + 2OH - (aq) → Mg(OH) 2 (s)

Question What is a spectator ion?

Answer 2 – 20 its an ion that is present in solution but does not participate in the reaction

Question What is the difference between a strong base and a strong acid?

Answer 2 – 30 Strong Acid completely dissociates into H + and anion in water Strong Base completely dissociates into OH - and cation in water

Question Explain how to distinguish between the following types of reactions: Single replacement Double displacement (precipitation) Synthesis Acid-Base

Answer 2 – 40 Single Replacement: element a + compound BC → element B + compound AC Double Displacement/precipitation: a solid forms after mixing solutions of 2 ionic compounds Synthesis: 2 reactants → 1 Product Acid-Base: form H 2 O from H+ and OH- ions

Question How do you recognize the correct chemical formula for an ionic compound?

Answer 2 – 50 When the (+) cation(s) combine with the (-) anion(s) in a ratio that results in a net charge of 0

Question How many zeros does Avogadro's Number have?

Answer 3 – zeros – 6.02 x

Question What is the molar mass of CO 2 expressed with 3 sig figs?

Answer 3 – g/mol – Carbon = g/mol – Oxygen = g/mol (2x) – Add all together = g/mol – 3 sig figs!

Question How many sig figs are in the measurement kg?

Answer 3 – 30 4 sig figs

Question If the reactants areNa ₂S and Cu(NO ₃) ₂, what will the products be?

Answer 3 – 40 NaNO₃ and CuS

Question Determine the: 1.Empirical Formula 2.Molecular Formula 3.Percent Composition Of a substance with the molar mass of 78 g/ mol Percent of C: 92.3 % Percent of H: 7.7 %

Answer 3 – 50

Question Stoichiometry heavily relies on _____ ratios.

Answer 4 – 10 Mole

Question A sample contains 27.1 g of calcium oxide. How many moles of calcium oxide are in the sample?

Answer 4 – mol

Question A 2.00 g sample of ammonia is mixed with 4.00 g of oxygen. Which is the limiting reactant and how much excess reactant remains after the reaction has stopped? 4 NH 3(g) + 5 O 2(g)  4 NO (g) + 6 H 2 O (g)

Answer 4 – 30 Limiting Reactant: Excess Reactant:

Question Define limiting reactant and excess reactant.

Answer 4 – 40 Limiting Reactant - The reactant in a chemical reaction that limits the amount of product that can be formed. The reaction will stop when all of the limiting reactant is consumed. Excess Reactant - The reactant in a chemical reaction that remains when a reaction stops when the limiting reactant is completely consumed. The excess reactant remains because there is nothing with which it can react.

Question g of FeCl 3 reacts with 52.0 g of H 2 S. What is the limiting reactant? What is the mass of HCl produced? What mass of excess reactant remains after the reaction?

Answer 4 – 50 Grams of HCL: 60.8 g Limiting Reactant: FeCl 3 Excess reactant: 23.6 g H 2 S

Question Is burning coal an exothermic or an endothermic reaction?

Answer 5 – 10 Exothermic; heat is leaving the system.

Question A 450 g piece of iron (specific heat: J/g°C ) is heated from 22 °C to 87°C. How much heat was necessary to cause this change?

Answer 5 – 20 13,000 J

Question Which of the following is not a state function? Distance, energy, or temperature?

Answer 5 – 30 Distance

Question How much energy is required to heat 7.40 mL of water from 25°C to 46°C?

Answer 5 – 40 q = mc delta T q = (7.40 g) (4.184 J/gC) (21 C) – 7.40 mL X 1g/1mL = 7.40 g water q = 650. J 7.40 mL X 1g/1mL = 7.40 g water

Question O 3  3O 2 ∆H = kilojoules O 2  2 O∆H = kilojoules NO + O 3  NO 2 + O 2 ∆H = kilojoules Calculate the Enthalpy (∆H) for the overall reaction: NO + O  NO 2

Answer 5 – 50 Reverse reaction 1 Reverse reaction 2 Multiply reaction 3 by 2 Add the reactions, then divide by 2 delta H = +427 KJ – 459 KJ – 2 (199 KJ) = -430 KJ / 2 = -215 KJ