Chemistry 101

Chapter 1: Chemistry & Measurements

&nbsp;Molecules can be described as

a mixture of two or more pure substances.&nbsp;

a mixture of two or more elements that has a specific ratio between components.

two or more atoms chemically joined together.

Give the composition of water:

two hydrogen atoms and two oxygen atoms.

&nbsp;one hydrogen atom and one oxygen atom.

two hydrogen atoms and one oxygen atom.

one hydrogen atom and two oxygen atoms.

Dalton's Atomic Theory states:

that all elements have several isotopes.

that matter is composed of small indestructible particles.

that the properties of matter are determined by the properties of atoms.

that energy is neither created nor destroyed during a chemical reaction.

that an atom is predominantly empty space.&nbsp;

Which of the following represent a valid hypothesis?

Sodium metal reacts violently with water.

Oxygen is a gas at room temperature.

Zinc metal reacts with yellow crystals of sulfur in a fiery reaction to produce a white powder of zinc sulfide. A chemist determines that 65.4 g of zinc reacts with 32.1 g of sulfur. How many grams of zinc sulfide could be produced from 36.9 g of zinc metal?

Identify a liquid:

Definite volume and definite shape.

Definite volume and no definite shape.

Definite shape and no definite volume.

No definite shape and no definite volume.

Choose the heterogeneous mixture from the list below:

Which of the following statements about the phases of matter is TRUE?

In both solids and liquids, the atoms or molecules pack closely to one another.

Gaseous substances have long-range repeating order.

There is only one type of geometric arrangement that the atoms or molecules in any solid can adopt.

Liquids have a large portion of empty volume between molecules.

A substance composed of 2 or more elements in a fixed, definite proportion is considered:

Which of the following are examples of physical change?

All of these are examples of physical change.

Which of the following is an intensive property?

What is the length of 1.85 kilometer in units of micrometer with the correct number of significant figures?

The result of (3.8621 * 1.5630) – 5.98 is properly written as:

Round the following number (0.0084977) into 4 digits with writing the answer in scientific notation.

Accuracy is defined as:

a measure of how often an experimental value can be repeated.

the closeness of a measured value to the true value.

the number of significant figures used in a measurement.

A student performs an experiment to determine the density of a sugar solution. She obtains the following results: 4.11 g/mL, 4.81 g/mL, 4.95 g/mL, 3.75 g/mL. If the actual value for the density of the sugar solution is 4.75 g/mL, which statement below best describes her results?

Her results are precise, but not accurate.

Her results are accurate, but not precise.

Her results are both precise and accurate.

Her results are neither precise nor accurate.

It isn't possible to determine with the information given.

If the temperature is 178°F, what is the temperature in degrees celsius?

The outside air temperature is 30°F, what is the temperature in Kelvin?

If the temperature is 25°C, what is the temperature in °F?

The density in (g/ml) of a metal piece that has a volume of 1.68 cm3 and amass of a 52.8 g is:

Determine the mass of an object that has a volume of 88.6 mL and a density of 9.77 g/mL.

Determine the density of an object that has a mass of 149.8 g and displaces 12.1 mL of water when placed in a graduated cylinder

Signals between the ECM and the cytoskeleton may be transmitted by:

The speed of a car is 32.0 miles/hour. What is its speed in m/s? (given 1 mile = 1609 m)

How many kL does a 1.25 × 108 cL sample contain?

If an object has a density of 8.65 g/cm3, what is its density in units of kg/m3?

If the walls in a room are 955 square feet in area, and a gallon of paint covers 15 square yards, how many gallons of paint are needed for the room? (3 ft = 1 yd)

Which of the following is the smallest volume?

If a room requires 25.4 square yards of carpeting, what is the area of the floor in units of ft2? (3 ft = 1 yd)

Determine the volume of an object that has a mass of 455.6 g and a density of 19.3 g/cm3.