Exam 1, Chem 107 Review Pt. 1

Sig Figs/Scientific Notation

100

How many Significant Figures are in 3.421 ?

4 Sig Figs

200

How many Significant Figures are in 0.00100

3 Sig Figs

300

How would I correctly report 10,000 with only 1 significant figure?

1 x 10⁴

400

1.005 x 2 = ???

2

500

42.005 - 10.1 = ???

31.9

Dimensional Analysis

100

Number of grams in 1 liter of water (1L = 1kg)

1000 g

200

How many moles of sodium chloride are produced after mixing 2 mol of Na⁺, with 3 mol of Cl^-.

2 mol of NaCl

300

How many grams of carbon dioxide are produced after burning 1 mol of CH₄ in the following reaction:

CH₄+ 2 O₂ = CO₂+ 2 H₂O

44.01 g of CO₂

400

Find the volume of a sphere(with a diameter of 16.00cm) given the formula: V=(4/3)πr³

Then, use dimensional analysis to report the volume in cubic meters.

V= 2145 cm³

V= 2.145 x 10^-3 m³​​​​

500

What is the mass(in grams) of the previous volume(2.145 x 10^-3 m³) if the density is 789 kg/m³ ?

1690 g.

Protons, Neutrons, Electrons

100

Who discovered the electron? And with what experiment?

JJ Thomson discovered the electron, specifically with the green cathode rays experiment.

200

How many neutrons are in the following isotopes: Carbon 12, Carbon 13, Carbon 14

6n, 7n, 8n

300

How many electrons are in the following: Cl, Cl^-, Na, Na⁺

17, 18, 11, 10

400

Which has more electrons: Ne or Na⁺

They have the same number of electrons!

500

Rank(from least to most) the following isotopes by number of neutrons: Carbon-14, Nitrogen 14, Gallium-69, Cadmium-110, Manganese-55

7(Nitrogen), 8(Carbon), 30(Manganese), 38(Gallium), 62(Cadmium)

Moles/Mass

100

How many atoms are in 1 mole of Helium atoms?

6.022 x 10²³ atoms

200

What is the molar mass of H3PO4 ?

98 g/mol

300

Find the mass of a sample with 2 moles of Calcium Chloride

221.96 g

400

C₃H₈ + 5 O₂ = 3 CO₂ + 4 H₂O

How many grams of CO₂ do I get after 1 mol of C₃H₈ is combusted?

132.03 g of CO₂

500

Find mass percent composition of Calcium in 1 mole of Calcium Carbonate

About 40.04%

Random/ Formulas

100

True or false:

Pure substances are aqueous solutions

Pure substances can be a compound

Pure substances are only atoms, never molecules

False, True, False

200

Categorize the following elements(names of their groups): Mg, Kr, Br, O, Fe, Li

Alkaline earth metal, Noble gas, Nonmetal, Nonmetal, Transition metal, alkali metal

300

Identify the following as cation, anion, or neutral element/molecule:

Ca²⁺, SO₄^2-, O₂, Na⁺, Cl^-, Xe

Cation, anion(and polyatomic ion), neutral molecule, cation, anion, neutral element

400

Calculate the Empirical Formula of a compound that contains 80% C, 20% H, and has a molar mass of about 30 g.

Then, find the Molecular Formula.

Empirical Formula: CH₃

Molecular Formula: C₂H₆

500

Formulas/Nomenclature:

Fe₂S₃ , Potassium Sulfite, CaCl₂ , Sodium Hydroxide, Hydroiodic acid, P₄O₁₀ , Boron Trifluoride

Iron (III) Sulfide, K₂SO₃, Calcium Chloride, NaOH, HI, Tetraphosphorus decoxide, BF₃