CHEM 2 EXAM

Fill in the Blanks HCl (aq) + KOH (aq) --> KCl (aq) + H2O (I) is an blank reaction

acid-base

Please show the net ionic equation for the reaction of Copper II chloride with silver acetate.

b

Solid aluminum reacts with gaseous chlorine. If you begin with 0.552 mol of aluminum and 0.887 mol of chlorine, what is the limiting reactant and theoretical yield of the product in moles?

b

Solid aluminum reacts with gaseous chlorine. If you begin with 0.552 mol of aluminum and 0.887 mol of chlorine, what is the limiting reactant and theoretical yield of the product in moles?

b Al, 0.552 mol AlCl3

C3H8 + 3O2 → 3CO2 + 4H2How many moles of oxygen are necessary to react completely with 4.0 moles of propane C3H8?

b 12 moles O2

Friends of yours give about 1000 g of nuts an about 1000 g of bolts, How many nuts (average mass 4.35g) were you given?

b 230 nuts

Write a molecular equation (predict products) for the gas evolution reaction that occurs when you mix aqueous nitric acid and aqueous sodium carbonate.

b 2HNO3(aq) + Na2CO3(aq) ⇒H2O (l) + CO2(g) + 2NaNO3 (aq)

If the average mass o a nut is 4.35 g and we have 14 nuts, what is the mass of all the nuts given?

b 60.9 g

Using answer from 5.14, Calculate percent yield for the following reaction: 2As(s) +3S(l)⇒As2S3(s) when 10.4 g of As reacts with 11.8 g of S to produce 14.2 g As2S3.

b 83.0%

What should not be done when predicting products of reactions?

b Carrying over subscripts.

Classify the following reaction: Calcium and hydrochloric acid produce calcium chloride and hydrogen gas

b single replacement

2NaBr (aq) + Ca(OH)2 (aq) ---> CaBr2(aq)

b - double replacement

Identify the reactant(s) in the following reaction:

both A and B

Based upon lab question 5.00, how much of which reactant was left over?

c 1 bolt

Copper II chloride reacts with Sodium nitrate. If 15 g of Copper II chloride react with 20 g of Sodium nitrate, how much excess reactant is left over in this reaction? Hint: Find out how much NaNO3 is used with limiting reactant

c 1.03 g

Using the equation for the creation of ammonia gas. How many liters of ammonia gas would be produced if we start with 22.3 L of hydrogen? Write your answer as a number with correct sig figs only. Be sure to use the conversion factor of 22.4 L= 1 mole of any gas and you can use the shortcut if you would like.

c 14.9 L NH3 (g)

Given the product is represented by and the average mass of a bolt is 10.64 g and the average mass of a nut is 4.35 g, what is the mass of one product?

c 19.34 g

Consider the simple synthesis reaction combining solid potassium and liquid bromine. How many grams of solid Potassium bromide would be produced with 17.8 g of solid potassium?

c 54.2 g KBr

2KClO3 → 2KCl + 3O2How many moles of oxygen are produced by the decomposition of 6.0 moles of potassium chlorate?

c 9.0 moles O2

Why is step 6 (above) not a subtraction only problem?

c Because you cannot subtract one substance from a different substance (in algebra cannot subtract x from y).

What is fermentation? Remember this relates to our mass to volume stoichiometry problems.

c Fermentation is the breakdown of carbohydrates in an environment where there isn't oxygen.

Why is the following reaction a redox reaction? Zn(s) + Fe2+ (aq)⇒ Zn2+ (aq) + Fe(s)

c Zn transfers two electrons to Fe 2+.

The reactant with amounts left over is called the blank reactant.

excess

Fill in the blanks FeCl3+ NaOH--> Fe(OH)3+ NaCl

1 3 1 3

Fill in the Blanks N2+ H2 NH3

1 3 2

If we have the following equation: 1 cup flour + 2 eggs + 1/2 tsp baking powder---> 5 pancakes How many pancakes can we make with 3 cups of flour? Express your answer as a number only with three sig figs

15.0

What is the amount in liters that one mole of an ideal gas can occupy? Enter your answer as a number only.

22.4

Write a balanced chemical equation for the following description:Aluminum metal reacts with copper (II) chloride to produce aluminum chloride and copper metal.

2Al + 3CuCl2-->2AlCl3 + 3Cu

For the following reaction, determine what the products of this reaction will be. When you have predicted the products, balance the equation and use a table of solubility products to determine which of the products (if any) will precipitate. Assume all reactions take place in water._NaC2H3O2 + H2SO4 --->

2NaC2H3O2(aq) + 1H2SO4(aq) --> Na2SO4(aq) + 2CH3COOH(aq) (noprecip

Hydrochloric acid can dissolve solid iron according to the following reaction: Fe(s) + 2HCl(aq)⇒FeCl2(aq) +H2(g) How much HCl could dissolve a 2.8 g iron padlock? Express your answer as a number with correct sig figs only.

3.7

Sodium chloride forms in this reaction between sodium and chlorine. How many moles of NaCl result from the complete reaction of 3.4 moles of Cl2? Assume that there is more than enough Na. Express your answer as a number with two sig figs only.

6

The Lewis structure of oxygen has blank valence electrons. Express your answer as a number.

6

Write the ionic equation for Iron III chloride and magnesium metal.

C

What do resonance structures show?

Different structures for the same compound.

What is the complete name of the most electronegative element in the periodic table?

Fluorine

In this type of reaction, two aqueous compounds produce a solid product.

Precipitation

What specific business/marketing job utilizes the concept of excess reactants?

Purchaser

Write a balanced equation for the reaction between solid silicon dioxide and solid carbon to produce solid silicon monocarbide and carbon monoxide gas.

SiO2(s) + 3C (s)-->SiC(s) + 2CO(g)

Lewis theory predicts that the formula for a compound between barium and sulfur:

a

How many grams of oxygen would form with 2.13 g of Mercury (II) oxide? Use the following equation: 2HgO (s)⇒ 2Hg (l) + O2(g)

a 0.0787 g O2

Since you need 2x as many nuts as bolts, what is the mass of the product you could make with 94 bolts using the same equation ?

a 1817.96 g

Using the answer from Lab Question 5.08, what is the mass of the left over reactant?

a 182.7 g

Given the mass of the excess reactant (answer from Lab Question 5.09), calculate the mass of the bolts you would need to use up all of the nuts.

a 223.44 g

Which element has the highest electron affinity?

a C

Why is hydrogen considered an exception to the octet rule?

a It only needs 2 valence electrons.

Which of the following elements have the least metallic character?

a Li

How is metallic character defined?

a Metallic character is defined as how readily an atom can lose an electron.

Which of the following atoms have the following electron configuration ?

a Na

Which of the following elements have the lowest ionization energy?

a Rb

How are the patterns seen in the periodic table for ionization energy and electron affinity related?

a They both have the same trends seen.

f a molecule has 2 bonded pairs and 2 lone pairs, what will its shape be?

a bent

What type of bond does bromine gas have?

a single bond

The central atom in the chlorite anion, is surrounded by:

a two bonding and two unshared pairs of electrons

Lewis theory predicts that the formula for a compound between calcium and carbide is.

aCaC2 bCa4C2

Lewis theory predicts that the formula for a compound between potassium and sulfur is:

b

What is the angle between electron groups if they have tetrahedral geometry?

b 109.5 degrees

How many electrons can exist in an orbital?

b 2

Using answer from Lab Question 5.06 and information from Lab Question 5.07 (188 nuts), how many of which reactant is left over?

b 42 nuts

How many electrons are being shared by a triple bond? (What is total number of electrons represented by the triple bond?)

b 6

The Lewis structure for oxygen gas includes which of the following?

b double bond

What is a valence electron?

b electrons in outermost shell

What is the molecular geometry of carbon dioxide?

b linear

Classify the following reaction: 3HBr (aq) + Al(Oh)3(aq) ---> 3H2O(I)+ AlBr3(aq)

b acid base

Which of the following answers shows a complete and balanced equation showing the reaction of nitric acid with potassium hydroxide?

b- HNO3(aq) + KOH(aq) -> KNO3 (aq) + H2O (I)

Define limiting reactant.

bReactant that runs out first (smaller). cThis is also the theoretical yield.

Lewis theory predicts that the formula for a compound between flourine and calcium is:

c

How many core electrons are in a chlorine atom? Hint see larger group number.

c 10

How many valence electrons are in a chlorine atom?

c 7

Which of the following statements about Lewis structures is FALSE?

c All of the above statements are true.

What is unique about nitrogen gas?

c Forms a triple bond.

For covalent compounds, how does polyatomic ions typically impact these structures?

c They add the amount of electrons needed.

A molecule that is polar (has uneven charges/is asymmetrical and not sharing electrons evenly) is also known as a:

c dipole

What is the molecular geometry of CCl4?

c tetrahedral

The central atom in the chlorate anion, is surrounded by:

c three bonding and one unshared pair of electrons

Stoichiometry can be applied to the making of lots of foods we all enjoy such as blank1 - , blank2 , blank4 - and blank3

cheese , chocolate , wine

How many valence electrons are in sulfur dioxide?

d 18

How many valence electrons are in the nitrate ion?

d 24

How many valence electrons are in the noble gases (Group VIIIA) all the way to the right of the periodic table.

d 8

Why don't the noble gases bond very often?

d A and C.

What is the octet rule?

d Atoms bond together by either transferring or sharing electrons so that all atoms obtain an outer shell with 8 electrons.

Which of the following atoms is the largest?

d Cs

Which of the following is considered a single group of electrons?

d all of these

Using Figure 6.7 on molecular geometries above, which structure would be shown for 4 lone pairs?

d linear

Neon has blank valence electrons. Enter the word.

eight

What does l refer to when placing phases within a chemical equation?

liquid

Fill in the Blanks AgNO3 (aq) + KCI (aq) --> AgCl(s) + KNO3 (aq)

precipitation

What type of reaction is the following: 2KI(aq) + Pb(NO3)2 (aq)---> PbI2(s) +2KNO3(aq)

precipitation

What is solubility of CaCl2?

soluble

What is the molecular geometry if you have 3 single bonds and 1 lone pair? Answer as a word only-may be more than one word.

trigonal pyramidal

STP stands for blank1 blank2 - and blank3 -and is used to incorporate the conversion factor that 1 mole of an ideal gas occupies 22.4 L.

standard temperature pressure

Classify the following reaction: magnesium metal reacts with hydrochloric acid to form aqueous magnesium chloride and hydrogen gas

a - single replacement

Classify the following reaction: Magnesium and oxygen gas produce magnesium oxide

a-Redox

Please show the ionic equation of the reaction of Copper II chloride with silver acetate.

A

What is a spectator ion?

a Ions that are unchanged on both sides of equation and do not participate in the reaction.

When placing aluminum into sulfuric acid, aluminum sulfate and hydrogen gas is formed. 18.2 g of aluminum produces blank g of hydrogen gas.

2.05

What stoichiometry steps are specifically used to calculate amount of excess reactant left over?

a Perform stoichiometry steps to convert from limiting reactant to excess reactant and then subtract that amount from the excess reactant given.

Which reactant gives us the theoretical yield?

a limiting

Based upon lab question 5.00, which reactant is limiting?

a nuts

What is the formula for percent yield?

a percent yield = actual yield/ theoretical yield x 100%

What type of reaction does the following statement describe? electrons are transferred from one substance to another

a-redox

Write an equation for the precipitation reaction (if any) that occurs when solutions of lead (II) acetate and sodium sulfate are mixed. If no reaction occurs, choose NO REACTION.

a - Pb(C2H3O2)2 (aq) + Na2SO4(aq)⇒ PbSO4 (s) + 2NaC2H3O2(aq)

Using the equation for the Haber-Bosch process here : 4NH3 +3O2⇒2N2+ 6H2O How many liters of nitrogen gas would be produced if we start with 22.3 L of ammonia? Write your answer as a number with correct sig figs only. Be sure to use the conversion factor of 22.4 L= 1 mole of any gas and you can use the shortcut if you would like.

11.2

Using the equation for winemaking, let's go in the opposite direction and go from volume to mass. How many grams of glucose are needed to produce with 28.3 L of carbon dioxide? Enter your answer as a number with correct sig figs only.

114.0

10.4 g of Arsenic reacts with 11.8 g of sulfur to produce 14.2 g of As2S3. Write the theoretical yield as a number only.

17.1

Fill in the Blanks NaBr+ CaF2--> NaF+ CaBr2

2 1 2 1

Fill in the Blanks NaCl+ F---->2 NaF + CL2

2 1 2 1

Fill in the blank to balance the equation (use a 1 if needed): C8H18+ O2--> CO2+ H2O

2 25 16 18

Review the photosynthesis reaction: 6 CO2 (g) + 6 H2O (l) -> 6 O2 (g) + C6 H12O6(aq) How many grams of glucose can be synthesized from 58.5 g of CO2? Assume there is more than enough water present to react with all of the CO2. Express your answer as a number only with three sig figs.

39.9

For the following reaction, determine what the products of this reaction will be. When you have predicted the products, balance the equation and use a table of solubility products to determine which of the products (if any) will precipitate. Assume all reactions take place in water.__ Cu(OH)2 + H3PO4 -->

3Cu(OH)2(aq) + 2H3PO4(aq) --> 6H2O(I) + Cu3(PO4)2(S)

Fill in the Blanks P+ O2---> P2O5

4 5 2

Using the equation above : 4NH3 +3O2⇒2N2+ 6H2O How many liters of nitrogen gas would be produced if we start with 13.28 L of ammonia? Write your answer as a number with correct sig figs only. Be sure to use the conversion factor of 22.4 L= 1 mole of any gas and you can use the shortcut if you would like.

6.64

K3PO4 + Al(NO3)3→ 3KNO3 + AlPO4How many moles of potassium nitrate are produced when 2.5 moles of potassium phosphate react? Write your answer as number only.

7.5

Using the equation for winemaking, how many liters of carbon dioxide would be produced with 287.62 g of glucose? Enter your answer as a number with correct sig figs only.

71.5

10.4 g of Arsenic reacts with 11.8 g of sulfur to produce 14.2 g of As2S3. What is the percent yield? Write your answer as a number with two sig figs only.

83.0

Classify the following reaction: 3Pb(s) + 2H3PO(aq) ---> 3H2(g) + Pb3(PO4)2(S)

a-single replacement

For the following reaction, determine what the products of this reaction will be. When you have predicted the products, balance the equation and use a table of solubility products to determine which of the products (if any) will precipitate. Assume all reactions take place in water. Feel free to use outside solubility chart if needed. __ (aq) this is actually slightly soluble-more on this in future classes+ __ HF (aq)--->

Ca(OH)2(aq) + 2HF (aq) ---> 2H2O (I) + CaF2 (s) (CaF2precipitates)

Fill in the Blanks The molecular equation that shows the reaction of Copper II chloride with silver acetate is blank Please show states of matter in parentheses and depict ---> to

CuCl2(aq) + 2AgC2H3O2(aq) ---> Cu(C2H3O2)2(aq) + 2AgCl(s)

Write an equation for the precipitation reaction that occurs (if any) when solutions of sodium carbonate and copper (II) chloride are mixed.

D - Na2CO3(aq) +CuCl2(aq)⇒CuCO3(s) + 2NaCl (aq)

Refer to the following chemical equation to answer this question: H2 + O2 --> 2H2O Explain this in words.

Two hydrogen atom combine with one oxygen molecule to produce two water molecules.

Write the molecular equation that show the reaction of Iron III chloride with magnesium metal.

a

Copper II chloride reacts with Sodium nitrate. If 15 g of Copper II chloride react with 20 g of Sodium nitrate, how much sodium chloride can be formed-use four sig figs in your response? Hint: Smallest amount is that 'theoretical yield.' Bear in mind, this answer will be used in the continuation of this problem to achieve the objective of finding amount of excess reactant left over.

a 12.36 g NaCl

1 cup flour + 2 eggs + 1/2 tsp baking powder ⇒5 pancakes How many pancakes can we make if we have 5 eggs? Assume we have enough of all other ingredients (more on this in section to follow).

a 12.5 pancakes but really only 12 then

How many moles of NaCl result from the complete reaction of 8.2 mol Cl2? Assume more than enough Na. 2Na(s) +Cl2(g) ⇒2NaCl(s) Answer with correct sig figs.

a 16 mol NaCl

Calculate limiting reactant and theoretical yield for the following reaction: 2As(s) +3S(l)⇒As2S3(s) when 10.4 g of As reacts with 11.8 g of S to produce 14.2 g As2S3.

a 17.1 LR is As.

Zn + 2HCl → ZnCl2+ H2How many moles of hydrogen are produced from the reaction of 3.0 moles of zinc with an excess of hydrochloric acid?

a 3.0 moles H2

If each set of nuts and bolts contains 8 bolts and 14 nuts and the equation is , how many products could you make?

a 7

Using the same equation and given that the average mass of a bolt is 10.64 g and the average mass of a nut is 4.35 g, what is the mass of all the bolts (8) given?

a 85.12 g

In the making of cheese (please note different pH levels result in different cheeses-more on pH in Chapter 9) , the bacteria ferment the sugar present in milk, called lactose (C12H22O11), into lactic acid (CH3CHOHCOOH), as follows:C12H22O11 + H2O ⇾ 4 CH3CHOHCOOHIf we start with 332.9 g of lactose, how many liters (theoretically-we are assuming in this equation it is a gas for the purposes of this problem) of lactic acid can be produced?

a 87.1 L Lactic acid

10.4 g of Arsenic reacts with 11.8 g of sulfur to produce 14.2 g of As2S3. What is the limiting reactant?

a As

Copper II chloride reacts with Sodium nitrate. If 15 g of Copper II chloride react with 20 g of Sodium nitrate, what is the limiting reactant? Use answer explanation and knowledge from 5.29 to answer.

a CuCl2

22.0 g of potassium reacts with 18.2 g of iodine. Calculate which reactant is limiting and how much product is made. LR=Limiting Reactant

a I2LR, 24.0 g KI

Using the reaction of 2 Na (s) + Cl2 (g) ---> 2 NaCl (s) If we have 53,2 g Na and 65.8 g of , what is the limiting reactant? Answer by writing the word for the product (not the formula).

chlorine, chlorine gas, CI2

Fill in the Blanks CH4 + 2O2 --> CO2 + 2H2O is a blank

combustion

Copper II chloride reacts with Sodium nitrate. If 15 g of Copper II chloride react with 20 g of Sodium nitrate, how many grams of Copper II nitrate are formed with four sig figs? Hint: Use limiting reactant starting amount.

d 20.93 g Cu (NO3) 2

Consider the following equation which shows the combustion of butane used in lighters: 2C4H10(g) + 13 O2(g) ⇒8CO2(g) +10 H2O (l). How many grams of water can be produced from 5.22 g of butane (C4H10)?

d 8.09 g H2O

What other reaction types can an acid-base reaction also be?

d B and C

What is the net ionic equation for the following reaction? Pb(NO3)2(aq) + 2LiCl(aq) ⇒ PbCl2(s) + 2LiNO3(aq)

d Pb2+ (aq) + 2Cl-(aq) ⇒PbCl2(s)

What is step 5 in stoichiometry problems?

d Use your mole ratio from the balanced chemical equation. (The mole conversion factor comes from the coefficients of the balanced chemical equation.)

What is the formula for percent yield?

d actual yield/theoretical yield x 100%

Classify the following reaction: 2NH3(aq) + H2SO4(aq) --> (NH4)2SO4(aq)

d - synthesis

Classify the following reactions: 4C5H9O (aq) + 2702 (g) --> 20Co2(g) 18H2O(I)

d combustion

Which of the following answers shows a complete and balanced equation showing the combustion of propane (C3H8)?

d. C3H8(g) + 50(g) -> 3CO2(g) + 4H2O(I)

Which of the following show evidence of a chemical reaction?

formation of gas

2HCl (aq) + K2S (aq) --> H2S (g) + 2KCl (aq) What type of reaction is this? End your answer with the word reaction.

gas-evolving reaction acid-base reaction

The blank reactant is the reactant that gets used up first and determines the amount of product for a problem.

limiting