ReleasedQuestions

ChemistryCA Standards Test

ReleasedQuestions

Measure temperature

Measure heat

Measure color of light

Observation Hypothesis Theory Law

(The Atomic Theory)A well-accepted idea.

Refer to yourPeriodic

Table

Chemical Families act the same.

Alkali metals (Li, Na, K…) are the easiest atoms to pull an electron off of.

Noble gases arethe hardest to pull anelectron off of.

Family 6 has6 valence electrons.

Most particles missed the nucleus

A few alpha particles hit something small and very dense!

single-atom

Cl2

F2

He

N2

The Diatomic Elements:

HONClBrIFor

BrINClHOF

The examples contain C, N, H, & O

nonmetals with nonmetals

http://www.bcssa.org/newsroom/scholarships/great8sci/Matter/GeneralInfo/Changes1.html

Use your Periodic TableSame family as Silicon

Volume decreases x2Pressure increases x2

At STP, 1.0 mole = 22.4 L

So, half a mole = 11.2 L

The answer is STP (T=273 K & P=1.00 atm)

K -273 = ºC423 - 273Remember, no calculator…

The answer is NOT negative.

And

423 – 273 696!

These mix very well so you can dissolve alcohol in water or water in alcohol!

Hint: Read the question before looking at the table of information…

“Like Dissolves Like”

Polar solutes dissolve in polar solvents.

Nonpolar solutes dissolve in nonpolar solvents.

Polar and nonpolar do not mix (e.g. oil & H2O).

A Proportion!If 36.2 g dissolves in 100 g of H2O,How much dissolves in 50 g of H2O?

Liters 5

moles ? M 2.0

Hint: If the math confuses you, try each answer until you find the right one.

ppm is related to %

100 solvent

solute %

1,000,000 solvent

solute ppm

1,000,000 1,000

g 332

Heat = mass x (change in Temp) x specific heat

= 30 g (40.0ºC) (0.4 J/g ºC) = 30 (4)(4) J = 120 x 4 = 480 J

From the formula sheet:

HCl + NaOH H2O + NaCl (salt water)

Salt water is neutral!

Our’s looked more like this:

Which answer is NOT an electrolyte?

Nope… bases are slippery.

Nope… acids + bases form salts.

Nope… they become less acidic… they get neutralized!

Acidic = Low pH

Basic = High pH

Le Châtelier's Principle

Reactants Products

Increase pressure =

decrease in volume

Not enough room… switch to the side that takes up less room

(fewer moles of gas)

21

Add heat… shift left

Add liquid… no change

Shift left… make O2

Fewer moles of gas on the right. 5 2

Shift right… use up CO

No change… 2 2

Shift right… make CO2

Shift left: use up NO

H2O(l) H2O(g)

4

CH3CH2OH is C2H6O

C2H6O + 3O2 2CO2 + 3H2O

Molar mass of carbon-12:

12.00 g/mole

moles 0.5 g/mole 12

grams 6

massmolar

grams moles

Or… 12 grams = 1 mole so… 6 grams = .5 moles

Approximate:

195 g = 1 mole… so 97.6 g = .5 mole

1 mole = 6.02 x 1023 atoms… so .5 mole =

3.01 x 1023 atoms!

Look up Pt on the Periodic Table

1 mole CO2 and 2 moles H2O are formed.

Translate:

6.02 x 1023 = 1 mole

1.2 x 1024 = 2 moles

Use P.O.E.

Process

Of

Elimination

Molar Mass of CH4

12.0 + 4.0 = 16.0 g/mole

moles 6 g/mole 16

grams 96

massmolar

grams moles

Hint: Again… if the math is too much… try each answer out.

52 g Cr = 6.02 x 1023 atoms

13 g Cr = ¼ x 6.02 x 1023 atoms

= 1.5 x 1023 atoms

1 Fe2O3 = 2(55.85) + 3(16.00) = 112 + 48 = 160 grams

3 CO = 3(12.0 + 16.0) = 3(28) = 84 grams

So… 160 grams Fe2O3 is needed to react with 84 grams of CO!

6(2+16) = 6(18) = 60 + 48 = 108 grams

2(14+3) = 2(17) = 34 grams

108 g H2O 34 g NH3

so…

54 g H2O 17 g NH3

Hint: The numbers have to be simple because you won’t have a calculator.