Midterm #2 Review

Nuclear Chemistry

100

Identify an alpha particle, a beta particle, a gamma ray, a positron, a neutron, or a proton

Good job

200

Draw the symbol for the isotope of lead that contains 128 neutrons.

Pb 128

     82

300

Write a nuclear equation for positron emission for   C-11

C-11 -> B-11 + Positron

400

A radioactive sample contains 2.45 g of an isotope with a half-life of 3.8 days. How much of the isotope in grams remains after 11.4 days?

.31g

500

Write the nuclear reaction for the neutron-induced fission of U-235 to produce Ba-139 and Kr-94. How many neutrons are produced in the reaction?

 3 neutrons

Compounds

100

Classify each compound as ionic or molecular

1. CS2

2. CuO

3. KI

4. PCl3

1. molecular

2. ionic

3. ionic

4. molecular

200

Determine whether the metal in each ionic compound forms only one type of ion or more than one type of ion and name the compound accordingly.

1. Cr2O3

forms more than one type of ion, chromium(III) oxide

300

Write a formula for the compound that forms from potassium and

1. acetate

2. chromate

1. KC2H3O2

2. K2CrO4

400

Name the compound

1. Na2O

2. SnO2

1. Sodium Oxide

2. Tin (IV) Oxide

500

provide the compound’s correct name.

1. Al4C3

2. Hg2SO4

3. Fe2S3

1. Aluminum Carbide

2. Mercury (I) Sulfate

3. Iron (III) Sulfide

Polar Vs. Nonpolar

100

Arrange these diatomic molecules in order of increasing bond polarity: ICl, HBr, H2H2, CO.

H2<IC1<HBr<CO

200

Write the Lewis structure for OCCl2OCCl2 (carbon is central) and determine whether the molecule is polar. Draw the three-dimensional structure of the molecule

polar 

trigonal planar

300

Determine whether each compound is ionic or covalent (if covalent, nonpolar or polar) and write the appropriate Lewis structure.

1. K2S

2. CHFO (carbon is central)

1. ionic,

2. covalent,

400

Determine electron and molecular geometry for 

A. Nitrite

Electron: trigonal planar 

Molecular: Bent

Polar

500

Polar Nonpolar? 

Electron geometry 

Molecular geometry 

Polar

tetrahedral

trigonal pyramidal 

Reactions

100

Write the chemical balanced equation

Gaseous carbon monoxide reacts with hydrogen gas to form gaseous methane (CH4)and liquid water.

CO+3 H2→CH4+H2O

200

Write the balanced chemical equation

Solid iron(III) oxide reacts with hydrogen gas to form solid iron and liquid water.

Fe2O3+3 H2→2 Fe+3 H2O

300

Which reactions are redox reactions?

1. Ba(NO3)2(aq)+K2SO4(aq)→BaSO4(s)+2 KNO3(aq)

2. Ca(s)+Cl2(g)→CaCl2(s)

1. not redox

2. redox

400

What is being oxidized and what is being reduced?

2 Fe₂O₃(s)+3 C(s)→4 Fe(s)+3 CO₂(g)

C is being oxidized 

Fe is being reduced

500

Write out the balanced single replacement reaction that occurs when you react aluminum with copper (II) sulfate

2 Al + 3 CuSO₄ -> Al₂(SO₄)₃ + 3 Cu

Limiting reagents

100

How many atoms are in 1 mol of atoms?

There are 6.022×1023atoms in 1 mole of atoms.

200

Consider the generic chemical reaction:

A+ 2 B → C + D 

Suppose you have 12 g of A and 24 g of B. Which statement is true?

1. A will definitely be the limiting reactant.

2. B will definitely be the limiting reactant.

3. A will be the limiting reactant if its molar mass is less than B.

4. A will be the limiting reactant if its molar mass is greater than B.

D

300

How many grams of Cl are in 38.0 g of each sample of chlorofluorocarbons (CFCs)?

1. CF2Cl2

2. CFCl3

1. 22.3g

2. 29.4g

400

For each reaction, calculate how many moles of product form when 1.75 mol of the reactant in italics. Assume there is more than enough of the other reactant.

1. H₂(g)+Cl₂(g)→2 HCl(g)

2. 2 H₂(g)+O₂(g)→2 H₂O(l)

1. 3.50 mol of HCl

2. 3.50 mol of H₂O

500

Sulfuric acid can dissolve aluminum metal according to the reaction:

2 Al(s)+3 H₂SO₄(aq)→Al₂(SO₄)3(aq)+3 H₂(g)

Suppose you wanted to dissolve an aluminum block with a mass of 22.5 g. What minimum amount of H₂SO₄ in grams do you need? How many grams of H₂ gas will be produced by the complete reaction of the aluminum block?

a. 123g H₂SO₄

b. 2.53g H₂