CHEM 148 Final Review 1

Unit Conversions

100

Convert 1.5 kilometers to meters.

1500 m 

200

A summer day reaches 95°F. Convert this temperature to degrees Celsius (°C).

35.0 °C

300

A grain of salt weighs 0.1 milligrams (mg). Convert this mass to micrograms (µg).

100 µg

400

A bacterium's mass is approximately 1.2 picograms (pg). Convert this mass to nanograms (ng).

0.0012 ng

500

The energy required to melt a block of ice is 150 kilocalories (kcal). Convert this energy to joules (J).

Hint: 1 calorie = 4.184 joules.

627,600 joules

Stoichiometry

100

Which coefficients would balance the following equation:

_Fe+ _O₂→ _Fe₂O₃

4,3,2

200

Calcium carbonate (CaCO₃) decomposes upon heating to form calcium oxide (CaO) and carbon dioxide (CO₂). The balanced equation is:

CaCO₃→CaO+CO₂

If you start with 50.0 g of CaCO₃, how many moles of CO₂ are produced?

0.499 mol of CO₂

300

Magnesium (Mg) reacts with hydrochloric acid (HCl) to form magnesium chloride (MgCl₂) and hydrogen gas (H₂). The balanced equation is:

Mg+2 HCl→MgCl₂+H₂

If you react 12.0 g of Mg, how many grams of H₂ will be produced?

0.994 grams of H₂

400

Hydrogen gas reacts with oxygen gas to form water. The balanced equation is:

2 H₂+O₂→2 H₂O

If 75g of H20 was produced when 10.0 g of H₂ reacts with excess oxygen gas, what is the percent yield?

84.1% yield

500

Nitrogen gas (N₂) reacts with hydrogen gas (H₂) to form ammonia (NH₃). The balanced equation is:

N₂+3 H2→2 NH₃

If you have 5.0 g of N₂ and 2.0 g of H₂, which reactant is limiting, and how many grams of NH₃ can be produced?

N₂ is the limiting reactant, and 6.08 grams of NH₃ will be produced.

Nomenclature

100

What is the name of the following compound

CaCl₂

Calcium Chloride

200

Write the formula for 

Copper (II) Sulfate 

CuSO₄

300

What is the name of the following compound

N₂O₅

Dinitrogen Pentoxide

400

What is the name of the following compound:

Fe₂O₃

Iron (III) Oxide

500

Write the formula for

Manganese (IV) Carbonate

Mn(CO3)₂

Acids & Bases

100

Consider the following reaction at equilibrium:

N₂(g)+3H₂(g)⇌2NH₃(g)

Kc =4.34×10⁵

Is this reaction product or reactant favored

Positive K value means product favored

200

What are the conjugate bases of the following compounds:

H₂0, H₂SO₄, HI, CH₃COOH

OH-, HSO4^-, H^-, CH₃COO^-

300

Arrange the following compounds by increasing acidity:

HF, HI, HBr, HCl, H20

H20<HF<HCl<HBr<HI

400

Calculate the pH of a solution that has a [OH^-] of 2.5x10^-8. Is the solution Acidic, Basic, or neutral?

Slightly acidic solution with a pH of 6.34

500

Write the equilibrium expression of the following equation:

Fe₂O₂(s)+3CO(g)⇌2Fe(s)+3CO₂(g)

Kc= [CO₂]³/[CO]³

Geometry

100

What is the molecular geometry and bond angles of 

CO₂

Is it polar or nonpolar?

Linear, 180 ⁰ , NP

200

What is the molecular geometry and bond angles of 

NH₃

Is it polar or nonpolar?

Trigonal-Pyramidal, Polar, <109.5

300

What is the molecular geometry and bond angles of 

BH₃

Is it polar or nonpolar?

Trigonal Planar, 120, NP

400

What is the molecular geometry and bond angles of 

CO₃^2-

Is it polar or nonpolar?

Trigonal Planar, 120, NP

500

What is the molecular geometry and bond angles of 

HOCl

Is it polar or nonpolar?

Bent, <109.5, Polar