Practice: Energy in Matter (7.3.5)

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7.3.5 Practice: Energy in Matter

Chemistry
Devon Gale
Points possible: 25

Question 1: Kinetic Theory and Absolute Zero (2 points)

a. What is absolute zero? What is the temperature of absolute zero on the Kelvin and Celsius scales? (1 point)

ABSOLUTE 0 IS THE THEORETICAL LOWEST NUMBER.
IN CELSIUS: -273.15degrees Celsius
IN KELVIN: 0 K





b. What does the kinetic theory say about the kinetic energy present in solids? (1 point)

KINETIC ENERGY IN SOLIDS ARE CONFINED TO THEIR CRYSTALLINE STRUCTURES AND CAN ONLY BEND, FLEX, AND VIBRATE IN A RELATIVELY FIXED POSITION. THE ENERGY IS LIMITED.






Question 2: Phase Diagrams (3 points)

a. Describe what a phase diagram is. (1 point)

A PHASE DIAGRAM IS A GRAPH THAT SHOWS WHICH PHASE SOMETHING WILL BE IN BASED ON THE AMOUNT OF PRESSURE AND TEMPERATURE. THE PHASES ARE SOLID, GAS, LIQUID.



b. Explain the changes in kinetic energy as a substance is heated to its melting point, and how these changes affect intermolecular forces during the heating process. (1 point)




















c. How do the phase diagrams for water and carbon dioxide differ? (1 point)








Question 3: Solids (5 points)

a. What is the difference between a crystalline solid and an amorphous solid? (1 point)

Amorphous solid:a solid with considerable disorder in its structure.
Crystalline solid: solids with highly regular arrangements of their components. There are three types of crystalline solids; ionic, molecular, and atomic.



b. Name the type of crystalline solid formed from the following structural units and describe how the solid is formed. (2 points)

i. Metal atoms (1 point)








ii. Nonmetal atoms (1 point)








c. Match each property of solids with its definition. (2 points)

A. Brittleness
B. Ductility
C. Conductivity
D. Malleability


D Ability to be bent or flattened

C Ability to move heat or charge

A Tendency to break rather than bend

B Ability to be stretched without breaking
Question 4: Solutions (6 points)

a. Is a solution a homogeneous mixture or a heterogeneous mixture? Explain your answer. (1 point)

A SOLUTION IS A HOMOGENEOUS MIXTURE. LIKE MILK. IT CONSISTS OF MORE THAN ONE THING BUT YOU CANNOT SEE IT. PIZZA IS A HETEROGENEOUS MIXTURE BECAUSE YOU CAN SEE MORE THAN ONE PHASE (CHEESE, MUSHROOMS, PEPPERONI, SAUSE, PEPPERS, CRUST) MAKING IT UP.



b. Match each term to its definition. (2 points)

A. Solute
B. Solvent
C. Solution
D. Solubility


A Substance that does the dissolving

D Amount of substance that can be dissolved

B Substance that is dissolved

C Mixture containing one substance dissolved in another substance

c. How can one make a supersaturated solution? (1 point)

BY SATURATING THE SOLUTION FULLY. YOU MUST ADD SOLUTE TO THE SOLVENT UNTIL NO MORE CAN BE DISSOLVED.



d. Describe the following concentration measurements. (2 points)

i. Molality (1 point)

The molarity (M) or molar concentration is the amount of solute, in moles, per liter of solution.






ii. Parts per million (1 point)

Parts per million - ppm - is commonly used as a measure of small levels of pollutants in air, water, body fluids, etc. Parts per million is the mass ratio between the pollutant component and the solution and ppm is defined as

ppm = 1,000,000 mc / ms (1)



Question 5: Effects of Solute on Solvent (2 points)

a. What effect does adding a solute to a solvent have on the freezing point of the solvent? What equation describes the effect? (1 point)

the temperature at which the solution freezes is lowered.



b. What effect does adding a solute to a solvent have on the boiling point of the solvent? What equation describes the effect? (1 point)

Adding a solute to a solution, or some liquid, causes the boiling point to increase.






Question 6: The Ideal Gas Law (7 points)

a. What is the mathematical equation for the ideal gas law? Identify each variable and give its units. (2 points)
















b. Match the special cases of each gas law with its description. A law may be used more than once. In the equations, k is a constant. (3 points)

A. Boyle's law
B. Charles's law
C. Avogadro's law
D. Dalton's law


_____ P1 V1 = P2 V2

_____ V/T = k

_____ V1 / T1 = V2 / T2

_____ V = kn

_____ PV = k

_____ Ptotal = P1 + P2 + P3 + …
c. Conditions at STP (2 points)

i. What is the temperature and pressure at STP? (1 point)

At STP the value for pressure is 101325Pascals &that of temperature is 273.15Kelvin


ii. What is the volume of 1 mole of any kind of gas at STP? (1 point)
molar volume