Chapter 1 (Intro to Chemistry)
Classify the following substances as solid, liquid, or gas: Steam, Syrup, Dust, Saltwater, Broken Glass.
Solid: Broken Glass and Dust
Liquid: Syrup and Saltwater
Gas: Steam
Describe the following terms: Isotope, Cation, and Anion.
Isotope - A single type of atom with various amounts of neutrons.
Cation - An ion with a positive charge
Anion - An ion with a negative charge
What's the difference between an ionic and covalent bond? Also, what is the difference between an empirical and molecular formula?
An ionic bond transfers electrons between a metal and a non-metal, while a covalent bond shares electrons between two non-metals.
The empirical formula provides the lowest relative number of atoms of each element in a compound, while the molecular formula gives the actual number of each element in a molecule of a compound.
Given the following balanced chemical reaction:
H2S + Cl2 → S + 2HCl
Identify which element is being oxidized and which element is the oxidizing agent.
Sulfur is being oxidized
Chlorine is the oxidizing agent
A hot air balloon is floating in earth's atmosphere with a pressure of 0.846 atm and temperature of 42.3 oC. In order to return to the earth's surface, the balloons volume of air decreases from 2.67 x 103 L to 2.16 x 103 L. If the new atmospheric pressure is 758 mmHg, what is the final temperature (in Celsius) of the balloon?
27.7 oC
Describe the following terms:
Physical change Chemical change
Homogeneous mixture Heterogeneous mixture
Physical change: A change in the state of a substance without changing the chemical nature of the compound.
Chemical change: A change in the chemical identity of a compound.
Homogeneous mixture: the composition of the mixture is the same throughout.
Heterogeneous mixture: the composition of the mixture is not uniform.
How many atoms of cobalt are contained in 8.23 g of cobalt?
8.41 x 1022 atoms
What is the empirical formula and molar mass of triphosphorous hexachloride?
Empirical Formula - PCl2
Molar Mass - 305.6 g/mol
Given the following unbalanced chemical reaction:
C2H6 + O2 → CO2 + H2O
If 216.2 grams of ethane gas (C2H6) are reacted with excess oxygen, how many grams of carbon dioxide are produced?
632.9 grams of CO2
An unknown gas moves with a speed of 513 m/s at a temperature of 27.2 oC. What is the molar mass of the gas in g/mol?
28.5 g/mol
How many nanometers (nm) are in 13.5 inches (in)?
3.43 x 108 nm
Given that an element has 43 protons, 56 neutrons, and 36 electrons, what is this element's atomic number, atomic mass number, and overall charge? Additionally, what element is this?
Atomic number - 43
Atomic mass number - 99
Charge - +7
Element - Technetium
Name the following compounds:
1. MgCl2 2. Ni2S3
3. OF2 4. BrO-
1. Magnesium Chloride
2. Nickel (III) Sulfide
3. Oxygen Difluoride
4. Hypobromite
Given the following balanced chemical equation:
Ca(OH)2 + 2HBr -> 2H2O + CaBr2
It takes 49.9 mL of 0.543 M calcium hydroxide to neutralize 17.6 mL of hydrobromic acid. What is the concentration of the acid?
3.08 M
A sample of an unknown gas has a density of 0.72 g/L at 221 K and under a pressure of 781 mmHg. What is the density of this gas at STP?
0.57 g/L
A 100mL sample of ocean water is collected in the Pacific Ocean. When the sample is boiled, 12.4g of salt is leftover. If the density of the sample was 1.073g/cm3, what was the original volume of clean water in the sample? (The density of pure water is 1.00g/cm3).
94.9 mL of clean water.
Copper exists as a mixture of two isotopes. Copper-63 is 69.17% abundant and it has a mass of 62.9296 amu. Copper-65 is 30.83% abundant and it has a mass of 64.9278 amu. Calculate the atomic mass of copper.
63.55 amu
Name the following compounds:
1. KH2PO4 2. HI
3. H2CO2 4. NH4OH
1. Potassium Dihydrogen Phosphate
2. Hydroiodic Acid
3. Carbonous Acid
4. Ammonium Hydroxide
Write the balanced net ionic equation for the reaction between iron (II) chloride and silver nitrate.
2Ag+ (aq) + 2Cl- (aq) -> 2AgCl (s)
Determine the total pressure and mole fractions of CO2 and H2O after 2.47 moles of C4H10 reacts completely with O2 in a 10.0L container at 60.0 oC. Assume no O2 remains after the reaction is complete.
2C4H10 (g) + 13O2 (g) -> 8CO2 (g) + 10H2O (g)
P = 60.8 atm
XCO2 =0.444
XH2O = 0.556
What is the density of a 2.00m steel rod that has a diameter of 6.73cm and weighs 55.8kg?
7840 kg/m3 or 7.84 g/cm3
Rubidium has two isotopes, one has a mass of 85 amu and the other has a mass of 87 amu. If the atomic mass of rubidium on the periodic table is 85.468, what is the percent abundance of each isotope?
Rb-85 = 76.6%
Rb-87 = 23.4%
Salicylic acid has a composition of 60.78% carbon, 4.38% hydrogen, and the rest is oxygen. Given that its molar mass is 138.121 g/mol, what is the empirical and molecular formula of this organic acid?
Empirical = Molecular = C7H6O3
Given the following reaction:
sodium carbonate (aq) + hydrochloric acid (aq) → sodium chloride (aq) + dihydrogen monoxide (l) + carbon dioxide (g)
If 4.32 grams of sodium carbonate react with 8.92 grams of hydrochloric acid, what is the limiting reagent? If the actual yield of sodium chloride is 3.65 g, what is the percent yield of sodium chloride?
L.R. - Na2CO3
% Yield - 76.7 %
A reaction between hydrochloric acid and aluminum produces hydrogen gas. This hydrogen gas is collected over water at 25 oC and a total pressure of 759 torr. If the volume of the hydrogen gas is 355 mL, then how many moles of hydrogen gas were produced? (Note the vapor pressure of water at 25 oC is 23.8 torr)
0.014 moles