Question 1

How many oxygen atoms are there in 7.00 g of sodium dichromate,Na2Cr2O7?

Accepted Answer

A) 0)187 oxygen atoms 
B) 2)30 × 1021 oxygen atoms 
C) 1)60 × 1022 oxygen atoms 
D) 1)13 × 1023 oxygen atoms 
A) 0)187 oxygen atoms 
B) 2)30 × 1021 oxygen atoms 
C) 1)60 × 1022 oxygen atoms 
D) 1)13 × 1023 oxygen atoms

Question 2

Which of the following statements about mass spectrometry is false?

Accepted Answer

A) Mass spectrometry can be used to determine the molecular weight of a compound. 
B) The curvature of the path in a magnetic field is determined by the mass of the ion. 
C) The paths of heavier ions are deflected more strongly than the paths of lighter ions. 
D) The sample is changed into positively charged ions. 
A) Mass spectrometry can be used to determine the molecular weight of a compound. 
B) The curvature of the path in a magnetic field is determined by the mass of the ion. 
C) The paths of heavier ions are deflected more strongly than the paths of lighter ions. 
D) The sample is changed into positively charged ions.

Question 3

When carbon dioxide dissolves in water,H+ is formed,which makes the solution acidic,as shown in the balanced equation below.
CO2 + H2O → HCO3- + H+
What is the percent yield if 0.0088 g of CO2 reacts with 900 g of H2O to form 0.000108 g of H+?

Accepted Answer

Question 4

Assume that the unshaded spheres in the buret represent HS1U1P1+S1S1P0 ions,the shaded spheres in the flask represent OHS1U1P1-S1S1P0 ions,and you are carrying out a titration of the base with the acid.  
-If the volumes in the buret and the flask are identical and the concentration of the acid in the buret is 0.500 M,what is the concentration of the base in the flask?

Accepted Answer

A) 0)333 M 
B) 0)500 M 
C) 0)667 M 
D) 0)750 M 
A) 0)333 M 
B) 0)500 M 
C) 0)667 M 
D) 0)750 M

Question 5

Balance the chemical equation given below,and determine the number of milliliters of 0.0300 M phosphoric acid required to neutralize 25.00 mL of 0.0150 M calcium hydroxide.
_____ Ca(OH)2(aq)+ _____ H3PO4(aq)→ _____ Ca3(PO4)2(s)+ _____ H2O(l)

Accepted Answer

A) 1)69 mL 
B) 8)33 mL 
C) 12.5 mL 
D) 18.8 mL 
A) 1)69 mL 
B) 8)33 mL 
C) 12.5 mL 
D) 18.8 mL

Question 6

Balance the chemical equation given below,and determine the number of grams of MgO needed to produce 15.0 g of Fe2O3.
_____ MgO(s)+ _____ Fe(s)→ _____ Fe2O3(s)+ _____ Mg(s)

Accepted Answer

A) 0)0877 g 
B) 1)26 g 
C) 3)78 g 
D) 11.4 g 
A) 0)0877 g 
B) 1)26 g 
C) 3)78 g 
D) 11.4 g

Question 7

How many moles are there in 3.00 g of ethanol,CH3CH2OH?

Accepted Answer

A) 0)00725 mol 
B) 0)0652 mol 
C) 15.3 mol 
D) 138 mol 
A) 0)00725 mol 
B) 0)0652 mol 
C) 15.3 mol 
D) 138 mol

Question 8

What is the identity of substance X if 0.380 mol of X weighs 17.5 g?

Accepted Answer

A) NO2 
B) NO3 
C) N2O 
D) N2O4 
A) NO2 
B) NO3 
C) N2O 
D) N2O4

Question 9

How many mL of a 0.175 M FeCl3 solution are needed to make 250.mL of a solution that is
0)300 M in Cl- ion?

Accepted Answer

A) 0)429 mL 
B) 143 mL 
C) 429 mL 
D) It is not possible to make a more concentrated solution from a less concentrated solution. 
A) 0)429 mL 
B) 143 mL 
C) 429 mL 
D) It is not possible to make a more concentrated solution from a less concentrated solution.

Question 10

When the reaction C4H10 + O2 → CO2 + H2O is balanced using the smallest whole number coefficients,the coefficient in front of O2 is ________.

Accepted Answer

Question 11

What is the balanced chemical equation for the reaction of element A (unshaded spheres)with element B (shaded spheres)as represented below?

Accepted Answer

A) A + B → AB 
B) 4A + 2B → 4AB 
C) A2 + B2 → A2B 
D) 2A2 + B2 → 2A2B 
A) A + B → AB 
B) 4A + 2B → 4AB 
C) A2 + B2 → A2B 
D) 2A2 + B2 → 2A2B

Question 12

The following diagram represents the reaction of A2 (unshaded spheres)with B (shaded spheres).How many moles of product can be produced from the reaction of 1.0 mol of A2 and 1.0 mol of B?

Accepted Answer

A) 0)5 mol of product 
B) 1)0 mol of product 
C) 3)0 mol of product 
D) 6)0 mol of product 
A) 0)5 mol of product 
B) 1)0 mol of product 
C) 3)0 mol of product 
D) 6)0 mol of product

Question 13

Given the chemical equation: N2 + 3 H2 → 2 NH3.On a macroscopic level,what do the coefficients mean?

Accepted Answer

A) 1 atom of nitrogen reacts with 3 atoms of hydrogen to give 2 atoms of ammonia. 
B) 1 mole of nitrogen reacts with 3 moles of hydrogen to give 2 moles of ammonia. 
C) 1 molecule of nitrogen reacts with 3 molecules of hydrogen to give 2 molecules of ammonia. 
D) All of these are true. 
A) 1 atom of nitrogen reacts with 3 atoms of hydrogen to give 2 atoms of ammonia. 
B) 1 mole of nitrogen reacts with 3 moles of hydrogen to give 2 moles of ammonia. 
C) 1 molecule of nitrogen reacts with 3 molecules of hydrogen to give 2 molecules of ammonia. 
D) All of these are true.

Question 14

7.0 g of nitrogen is reacted with 5.0 g of hydrogen to produce ammonia according to the chemical equation shown below.Which one of the following statements is false?
N2(g)+ 3 H2(g)→ 2 NH3(g)

Accepted Answer

A) 3)5 g of hydrogen are left over. 
B) Hydrogen is the excess reactant. 
C) Nitrogen is the limiting reactant. 
D) The theoretical yield of ammonia is 15 g. 
A) 3)5 g of hydrogen are left over. 
B) Hydrogen is the excess reactant. 
C) Nitrogen is the limiting reactant. 
D) The theoretical yield of ammonia is 15 g.

Question 15

Calcium phosphate reacts with sulfuric acid to form calcium sulfate and phosphoric acid.What is the coefficient for sulfuric acid when the equation is balanced using the lowest whole-numbered coefficients?

Accepted Answer

A) 1 
B) 2 
C) 3 
D) none of these 
A) 1 
B) 2 
C) 3 
D) none of these

Question 16

If the reaction of phosphate ion with water is ignored,what is the total concentration of ions in a solution prepared by dissolving 3.00 g of K3PO4 in enough water to make 350.mL of solution?

Accepted Answer

A) 0)0101 M 
B) 0)0404 M 
C) 0)162 M 
D) 0)323 M 
A) 0)0101 M 
B) 0)0404 M 
C) 0)162 M 
D) 0)323 M

Question 17

When a 1.0 M solution of NaCl at 25°C is heated to 55°C,the

Accepted Answer

A) density decreases and the molarity decreases. 
B) density decreases and the molarity increases. 
C) density increases and the molarity decreases. 
D) density increases and the molarity increases. 
A) density decreases and the molarity decreases. 
B) density decreases and the molarity increases. 
C) density increases and the molarity decreases. 
D) density increases and the molarity increases.

Question 18

The following diagrams represent the reaction of A2 (shaded spheres)with B2 (unshaded spheres).How many moles of product can be made from 1.0 mol of A2 and 1.0 mol of B2?

Accepted Answer

A) 0)67 mol product 
B) 1)0 mol product 
C) 2)0 mol product 
D) 3)0 mol product 
A) 0)67 mol product 
B) 1)0 mol product 
C) 2)0 mol product 
D) 3)0 mol product

Question 19

How many iron(II)ions,Fe2+ are there in 5.00 g of FeSO4?

Accepted Answer

A) 5)46 × 10-26 iron (II)ions 
B) 1)98 × 1022 iron (II)ions 
C) 1)83 × 1025 iron (II)ions 
D) 4)58 × 1026 iron (II)ions 
A) 5)46 × 10-26 iron (II)ions 
B) 1)98 × 1022 iron (II)ions 
C) 1)83 × 1025 iron (II)ions 
D) 4)58 × 1026 iron (II)ions

Question 20

What is the concentration of NO3- ions in a solution prepared by dissolving 25.0 g of Ca(NO3)2 in enough water to produce 300.mL of solution?

Accepted Answer

A) 0)254 M 
B) 0)508 M 
C) 0)672 M 
D) 1)02 M 
A) 0)254 M 
B) 0)508 M 
C) 0)672 M 
D) 1)02 M

Exam 3: Formulas, equations, and Moles

How many oxygen atoms are there in 7.00 g of sodium dichromate,Na2Cr2O7?

Which of the following statements about mass spectrometry is false?

When carbon dioxide dissolves in water,H+ is formed,which makes the solution acidic,as shown in the balanced equation below. CO2 + H2O → HCO3- + H+ What is the percent yield if 0.0088 g of CO2 reacts with 900 g of H2O to form 0.000108 g of H+?

Balance the chemical equation given below,and determine the number of milliliters of 0.0300 M phosphoric acid required to neutralize 25.00 mL of 0.0150 M calcium hydroxide. _____ Ca(OH)2(aq)+ _____ H3PO4(aq)→ _____ Ca3(PO4)2(s)+ _____ H2O(l)

Balance the chemical equation given below,and determine the number of grams of MgO needed to produce 15.0 g of Fe2O3. _____ MgO(s)+ _____ Fe(s)→ _____ Fe2O3(s)+ _____ Mg(s)

How many moles are there in 3.00 g of ethanol,CH3CH2OH?

What is the identity of substance X if 0.380 mol of X weighs 17.5 g?

How many mL of a 0.175 M FeCl3 solution are needed to make 250.mL of a solution that is 0)300 M in Cl- ion?

When the reaction C4H10 + O2 → CO2 + H2O is balanced using the smallest whole number coefficients,the coefficient in front of O2 is ________.

What is the balanced chemical equation for the reaction of element A (unshaded spheres)with element B (shaded spheres)as represented below?

The following diagram represents the reaction of A2 (unshaded spheres)with B (shaded spheres).How many moles of product can be produced from the reaction of 1.0 mol of A2 and 1.0 mol of B?

Given the chemical equation: N2 + 3 H2 → 2 NH3.On a macroscopic level,what do the coefficients mean?

7.0 g of nitrogen is reacted with 5.0 g of hydrogen to produce ammonia according to the chemical equation shown below.Which one of the following statements is false? N2(g)+ 3 H2(g)→ 2 NH3(g)

Calcium phosphate reacts with sulfuric acid to form calcium sulfate and phosphoric acid.What is the coefficient for sulfuric acid when the equation is balanced using the lowest whole-numbered coefficients?

If the reaction of phosphate ion with water is ignored,what is the total concentration of ions in a solution prepared by dissolving 3.00 g of K3PO4 in enough water to make 350.mL of solution?

When a 1.0 M solution of NaCl at 25°C is heated to 55°C,the

The following diagrams represent the reaction of A2 (shaded spheres)with B2 (unshaded spheres).How many moles of product can be made from 1.0 mol of A2 and 1.0 mol of B2?

How many iron(II)ions,Fe2+ are there in 5.00 g of FeSO4?

What is the concentration of NO3- ions in a solution prepared by dissolving 25.0 g of Ca(NO3)2 in enough water to produce 300.mL of solution?

Chemistry: Matter and Measurement

Atoms, molecules, and Ions

Reactions in Aqueous Solutions

Periodicity and the Atomic Structure of Atoms

Ionic Bonds and Some Main-Group Chemistry

Covalent Bonds and Molecular Structure

Thermochemistry: Chemical Energy

Gases: Their Properties and Behavior

Liquids,solids,and Phase Changes

Solutions and Their Properties

Chemical Kinetics

Chemical Equilibrium

Aqueous Equilibria: Acids and Bases

Applications of Aqueous Equilibria

Thermodynamics: Entropy, free Energy, and Equilibrium

Electrochemistry

Hydrogen, oxygen, and Water

The Main-Group Elements

Transition Elements and Coordination Chemistry

Metals and Solid-State Materials

Nuclear Chemistry

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Filters

How many oxygen atoms are there in 7.00 g of sodium dichromate,Na₂Cr₂O₇?

When carbon dioxide dissolves in water,H+ is formed,which makes the solution acidic,as shown in the balanced equation below. CO₂ + H₂O → HCO₃^- + H⁺ What is the percent yield if 0.0088 g of CO₂ reacts with 900 g of H₂O to form 0.000108 g of H⁺?

Balance the chemical equation given below,and determine the number of milliliters of 0.0300 M phosphoric acid required to neutralize 25.00 mL of 0.0150 M calcium hydroxide. ___ Ca(OH)₂(aq)+ _ H₃PO₄(aq)→ _ Ca₃(PO₄)₂(s)+ ___ H₂O(l)

Balance the chemical equation given below,and determine the number of grams of MgO needed to produce 15.0 g of Fe₂O₃. ___ MgO(s)+ _ Fe(s)→ _ Fe₂O₃(s)+ ___ Mg(s)

How many moles are there in 3.00 g of ethanol,CH₃CH₂OH?

How many mL of a 0.175 M FeCl₃ solution are needed to make 250.mL of a solution that is 0)300 M in Cl^- ion?

When the reaction C₄H₁₀ + O₂ → CO₂+ H₂O is balanced using the smallest whole number coefficients,the coefficient in front of O₂ is ________.

The following diagram represents the reaction of A₂ (unshaded spheres)with B (shaded spheres).How many moles of product can be produced from the reaction of 1.0 mol of A₂ and 1.0 mol of B?

Given the chemical equation: N₂ + 3 H₂ → 2 NH₃.On a macroscopic level,what do the coefficients mean?

7.0 g of nitrogen is reacted with 5.0 g of hydrogen to produce ammonia according to the chemical equation shown below.Which one of the following statements is false? N₂(g)+ 3 H₂(g)→ 2 NH₃(g)

If the reaction of phosphate ion with water is ignored,what is the total concentration of ions in a solution prepared by dissolving 3.00 g of K₃PO₄ in enough water to make 350.mL of solution?

The following diagrams represent the reaction of A₂ (shaded spheres)with B₂ (unshaded spheres).How many moles of product can be made from 1.0 mol of A₂ and 1.0 mol of B₂?

How many iron(II)ions,Fe²⁺ are there in 5.00 g of FeSO₄?

What is the concentration of NO₃^- ions in a solution prepared by dissolving 25.0 g of Ca(NO₃)₂ in enough water to produce 300.mL of solution?