Chemistry Semester 1 Exam Review (Tests for Ch. 1-5)

How should the number 1.230E3 be properly expressed as a decimal?

1230.

409 Kelvin equals ______°C.

136

The standard temperature for gases is _________°C.

0

What volume of 18 M acid must be used to prepare 2.30 L of 0.145 M H2SO4?

0.02 L or 20. mL

A scientist obtains the number 0.045006700 on a calculator. If this number actually has four (4) significant figures, how should it be written?

0.04501

What are the four parts to Dalton's atomic theory?

1. All atoms of the same element are identical. 2. Compounds are combinations of different atoms. 3. A chemical reaction changes the way atoms are grouped together. 4. Atoms are indestructible.

Calculate the mass of sodium oxide produced from 1.5 g sodium metal in 3.5 L of oxygen gas. What is the limiting reactant? Also calculate the excess reactant not used in the reaction. (Write out chemical equation).

1. Mass of sodium oxide: 2.0 g 2. Excess reactant not used (oxygen gas): 3.13 L 3. Limiting reactant: Sodium

What are the parts of the kinetic molecular theory?

1. The moving particles undergo perfectly elastic collisions with the walls of the container. 2. The forces of attraction and repulsion between the particles are insignificant. 3. The average kinetic energy of the particles is directly proportional to the absolute temperature.

Calculate the ratio of the effusion rates of N2 and N2O.

1.25

How many moles of hydrogen sulfide are contained in a 49.7 g sample of this gas?

1.46 mol

Suppose that you purchases a water bed with the dimensions 2.55 m * 2.53 dm * 235 cm. What mass of water (in grams) does this bed contain?

1.52E6 grams

A physics experiment is conducted at a pressure of 14.4 kPa. What is this pressure in mmHg?

108 mmHg

Calculate the molarity of a solution that contains 22.6g potassium chloride in 150.0 mL of water.

2.02 M

Convert 6.8 feet to cm.

2.1E2 cm

Calculate the molar mass of barium sulfate.

217.40 g/mol

Naturally occurring element X exists in three isotopic forms: X-28 (27.977 amu, 92.93% abundance), X-29 (28.976 amu, 4.67% abundance), and X-30 (29.974 amu, 3.10% abundance). Calculate the atomic weight of X.

28.09 amu

How many parts of Dalton's atomic theory are still scientifically accepted?

3

Convert 7.9 lb to kg. (1kg=2.205 lb)

3.6 kg

What is the concentration of Na+ ions in a solution containing 54.5 g of sodium phosphate in 250 ml if water>

3.99M

What amount of 2.60 M H2SO4 is needed to neutralize 50.0 mL of 3.65 M NaOH?

35.1 mL H2SO4

What volume of 0.150 M sodium phosphate solution is required to precipitate all of the solid from 255 mL of a 0.325 M lead II nitrate solution?

368 mL

How many significant figures are there in the number 0.0006428?

4

How many grams of NaCl are contained in 250. mL of a 0.287 M solution of sodium chloride?

4.19 g NaCl

A mixture of gases has a total pressure of 212 mmHg. If the mixture contains 80. mmHg of O2, 40 mmHg of CO2, 0.055 atm of H2, and the remained is Cl2, calculate the pressure of Cl2.

50.2 mmHg

A 5.95 g sample of AgNo3 is reacted with excess BaCl2 to give 3.17 g of AgCl. What is the percent yield of AgCl. (Write a chemical equation.)

63.15%

What mass of barium sulfate can be produced when 150.0 mL of a 0.200M BaCl2 solution is mixed with 200.0 mL of a 0.150M Fe2(S04)3 solution?

7.002 g BaSO4

An oxide of iron has the formula Fe3O4. What mass percent of iron does it contain?

72%

When 233.1 g of ethylene (C2H4) burns in oxygen to give carbon dioxide and water, how many grams of CO2 are formed?

731.2 g

The element rhenium (Re) exists as two stable isotopes and 18 unstable isotopes. Rhenium-185 has in its nucleus _______ protons and _______ neutrons.

75 protons; 110 neutrons

8.1 kilogram(s) contain ____________ grams.

8.1E2

A ____________ electrolyte dissociates to a great extent in an aqueous solution.

Strong

Pressure is defined as ____________.

The force per unit area

By knowing the number of protons a neutral atom has, you should be able to determine what two things?

The number of electrons in the neutral atom and the name of the atom (protons).

Graham's law states that ___________.

The rates of effusion of gases are inversely proportional to the square roots of their molar masses

Dalton's law of partial pressures states that ______________.

The total pressure of a mixture of gases is the sum of the partial pressure of all of the gaseous compounds

Boyle's law states that ____________.

The volume of a fixed amount of gas is inversely proportional to its pressure at constant temperature

The maximum possible yield of a chemcal reaction is known as the ____________.

Theoretical yield

Which metals form cations with varying positive charges?

Transition metals

T/F: A base is a substance that produces OH- ions in water.

True

T/F: A chemical that changes color at the endpoint of a reaction is called an indicator.

True

T/F: Evangelista Torrecelli invented the manometer (barometer) to measure air pressure.

True

T/F: Negatively charged polyatomic ions that contain oxygen are known as oxyanions.

True

T/F: Oxidation is the loss of electrons.

True

What is the law of multiple proportions?

When two elements combine with each other to form more than one compound, the weights of one element that combine with a fixed weight of the other are in a ratio of small whole numbers. ex. NO and NO2

Aqueous solutions of sodium sulfide and copper(II) chloride are mixed together. Will a precipitate form and if so, what is it?

Yes; CuS

What is the name of NaClO4?

Sodium perchlorate

The ability to dissolve in water is known as _____________.

Solubility

The substance that dissolves another substance is known as the _____________.

Solvent

What is the chemical formula of sulfurous acid?

H2SO3

A solution is also called a ________________.

Homogeneous mixture

What is the name of HBr?

Hydrobromic acid

A substance that does not ionize in a solution is known as a ___________________.

Nonelectrolyte

A molecule with an equal charge distribution is said to be a ___________ molecule.

Nonpolar

The SI unit of pressure is the ______________.

Pascal

The boiling of water is a ________________ change because the gaseous water is chemically the same as the liquid.

Physical

What is the name of KNO3?

Potassium nitrate

The degree of agreement among several measurements of the same quntity is called _______. It relflects the reproducibility of a given type of measurement.

Precision

Complete the following equation and find the net ionic equation. Two aqueous solutions of silver nitrate and sodium bromide are cobined in an exchange reaction.

Ag+ (aq) + Br- (aq) --> AgBr (s)

What is the chemical formula of silver bromide?

AgBr

Rutherford's experiment was important because it showed that _______________.

An atom is mostly empty space.

Gaseous chlorine is held in two separate containers at identical temperature and pressure. The volume of container 1 is 1.30 L, and it contains 6.70 mol of the gas. The volume of container 2 is 2.33 L. How many moles of the gas are in container 2? What law does this demonstrate?

Avogadro's; n2=12.0 mol

What is the name of BO3?

Boron trioxide

A 2.5 L of a gas is held at 397 kPa. If volume of the gas increases to 5.0 L, what is the new pressure (in atms) if temperature is held constant? What law does this demonstrate?

Boyle's; P2= 1.96 atm

The empirical formula of styrene is CH; its molar mass is 104.1 g/mol. What is the molecular formula of styrene?

C8H8

What is the chemical formula of calcium iodide?

CaI2

A sample of helium gas occupies 14.7 L at 23°C and 0.956 atm. What volume will it occupy at 40°C and 1.20 atm? What law does this demonstrate?

Combined; v2= 12.4 L

T/F: The standard temperature is 100K and the standard pressure is 1 atm.

False- The standard temperature is 0°C and the standard pressuure is 1 atm.

What is the name of P2O3?

Diphosphorus trioxide

A reaction in which ions are rearranged to form two new compounds is known as _________. These reactions often produce a precipitate.

Double replacement/exchange

T/F: Binary molecular compounds contain metals and nonmetals.

False- ionic compounds contain metals and nonmetals.

T/F: A homogenous solution is also known as a mixture.

False- A homogenous mixture is also known as a solution.

T/F: An oxidizing agent is an electron donor.

False- A reducing agent is an electron donor.

T/F: All physical changes create a new substance.

False- All chemical changes create a new substance.

T/F: At the same temperature, lighter molecules have higher average kinetic energy than heavier molecules.

False- At the same temperature, lighter molecules have the same average kinetic energy as heavier molecules.

T/F: Nonmetals appear in the upper left hand corner of the periodic table.

False- Metals appear in the upper left hand corner of the periodic table.

T/F: Pressure and volume of a gas are directly proportional at constant temperature.

False- Pressure and volume of a gas are indirectly proportional at constant temperature.

T/F: All transition elements have multiple charges and need Roman numerals in their compound names.

False- Some transition elements have multiple charges and need Roman numerals in their compound names.

What is the chemical formula of Iron III hydroxide?

Fe(OH)3

An excess of sodium hydroxide is treated with 26.5 L of dry hydrogen chloride gas measured at STP. What is the mass of sodium chloride formed? What law does this demonstrate?

Ideal; 69.0 g NaCl

If a 17.90 g sample of a gas occupies 10.0 L at STP, what is the molar mass of the gas? What law does this demonstrate?

Ideal; M= 40.1 g/mol

Calculate the empirical formula for the compound with K 26.6%, Cr 34.4%, and O 38.0%.

K2C2O7 Potassium dichromate

What is the chemical formula of lithium carbonate?

Li2CO3

____________ is defined as moles of solute per volume of solution in liters.

Moalrity

A gaseous mixture containing 57 g Ar and 154 g CO2 has a total pressure of 7.3 atm. What is the partial pressure of CO2? What law does this demonstrate?

Mole fraction/ Dalton's; P CO2= 5.2 atm