Last Chem Test Review!

SE04 Multiple Choice Review!

Breakdown for today:

1. Review (this!) for the first 45 min.

   1. Remember, this will be very similar to the exam, which has 16 questions!

2. Take the MC portion of the exam for 40 min.

3. Turn in materials/get ready to go.

Semester 1 Topics

4 Questions

When you write the atomic symbol, you include the mass number at the top left, the atomic number bottom left, and the symbol in the center.

​

Isotope Notation

You can use the APEMAN to create the symbol by finding the mass and atomic number, or deconstruct the symbol using APEMAN.

​

Isotope Notation

​Atomic # = # Protons = # Electrons	​Mass # = Atomic # + # Neutrons
​Since A is the bottom left, the atomic number is 6, as is the number of protons and electrons.	​Since M = 14 and A = 6, we can find the neutrons using the equation:

Elements that exist in pairs when they are alone are called diatomic elements. There are 7 elements that are diatomic:
H₂, N₂, O₂, F₂, Cl₂, Br₂, I₂

​

Diatomic Elements

1. Name the metal (first element)

2. Name the nonmetal by changing to end in -ide, unless its an ion on the back of the periodic table.

​Ionic Compounds

Naming Compounds

Fill in the Blanks

What's the atomic number for the element shown?

Fill in the Blanks

What's the mass number for the element shown?

Multiple Choice

How many protons, neutrons, and electrons are in the symbol shown?

• 56 p, 81 n, 56 e

• 137 p, 56, 137 e

• 56 p, 137 n, 56 e

• 56 p, 193 n, 56 e

Quarter 3 Topics

3 Questions

Conversions

When there's no equation:

How many molecules (particles) are in 15 g O₂?​

Example

Conversions

When there's an equation:

Example

How many grams of Bromine are needed to create 150 grams of Sodium Bromide?
2Na + Br₂ → 2 NaBr 

Multiple Choice

48.86 g of cobalt is equal to how many moles of cobalt?

• 2879 moles

• 8.291 moles

• .8291 moles

• .829 moles

Multiple Choice

What is the mass of 4.98 x 10²⁴ atoms (particles) of Zn?

• 541 g

• 8.27 g

• .122 g

• 4.59 x 10⁴⁶ g

Multiple Choice

2Al + 6HCl --> 2AlCl₃ + 3H₂

Aluminium reacts with hydrochloric acid. How many grams of aluminum are necessary to produce 11 L of hydrogen gas at STP?

• 13

• 8.8

• 0.99

• 1.0

Helps us determine if a reaction will occur for single replacement reactions.
The higher it is, it wants to be in a compound (more reactive it is).

Activity Series

Multiple Choice

Which of the following metals is the most reactive according to the reactivity series of metals.

• Copper
• Zinc
• Magnesium 
• Lithium

Multiple Choice

Which metal is more reactive than calcium?

• magnesium

• potassium

• silver

• aluminum

Multiple Choice

If single element is above the element in compound, then the reaction ________________occur.

• will

• will not

We can use the relative amount as a percentage by making them into grams! Ex: 30% nitrogen and 70% oxygen would be 30 g N and 70 g O

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Empirical Formulas

If a sample of a compound is 30% nitrogen by mass and 70% oxygen by mass, what would be the empirical formula?

Empirical Formulas

Multiple Choice

A compound consists of 72.2% magnesium(Mg) and 27.8% nitrogen(N) by mass. What is the empirical formula?

• Mg₄N₃
• MgN₂
• Mg₃N₂ 
• MgN

Quarter 4 Topics

9 Questions

Gas Laws

Gases follow a set of rules that allow for us to predict how they will exist or change given a set of conditions.

Variables to know:
P = Pressure; V = Volume; n = moles;
R = Gas Constant; T = Temperature

Pressure, volume, temperature, and the amount of particles are all related!

​​Ideal Gas Law

Volume and pressure are inversely related, so if one goes up, the other goes down.

​​Boyle's Law

Volume and temperature are directly related, so if one goes up, the other goes up.

​​Charles' Law

​Temperature and pressure are directly related, so if one goes up, the other goes up.

​​Gay-Lussac's Law

EQUATIONS ARE ON THE BOARD!

• Releases energy/heat to surroundings

• Increases surrounding temps

• -Q and -ΔH

​Exothermic

• Absorbs energy/heat from surroundings

• Decreases surrounding temps

• +Q and +ΔH

​Endothermic

Thermochemistry

Heat flows from my cup to my water, making my cup colder and my water warmer. I should definitely put ice in it.

​Ex 2

Heat flows from the oven to the pizza, which made my dinner. Don't judge me. It was from Walmart.

Ex 1

Heat flows from hot to cold (or less hot!)

Specific Heat Calculations!

Q = mc_pΔT

Q = energy/heat (needs to + or -)
m = mass
c_p = specific heat (use your chart!)
ΔT = change in temp (T₂ - T₁)

Multiple Choice

An ___________________ process is a process that releases energy.

• exothermic

• endothermic

Multiple Choice

What is the ΔH of this reaction?

• 40 kJ

• 20 kJ

• 80 kJ

• -60 kJ

Multiple Choice

What letter represents the energy of the products?

• A
• B
• C
• D

Multiple Choice

What is the sign of ΔH for all endothermic reactions?

• Positive
• Negative

Multiple Choice

What is the change of the heat of the reaction (ΔH)?

• -40 kJ

• -20 kJ

• 100 kJ

• 60 kJ

Multiple Choice

What is the PE of the reactants?

• 100 kJ
• 175 kJ
• 50 kJ
• 75 kJ

Multiple Choice

What is the change of the heat of the reaction (ΔH)?

• 100 kJ

• -175 kJ

• -50 kJ

• 75 kJ

Multiple Choice

A material was cooled from 100ºC to 40ºC.  What is the temperature change?

• 60ºC
• 40ºC
• -60ºC
• -40ºC

Multiple Choice

A sample of iron receives 50.J of heat energy that raises the temperature of the iron by 25.0°C. If iron has a specific heat of 0.10 J/g°C, what is the mass of the iron sample?  (show your work)

• 25g
• 30g
• 20g
• 50g

Multiple Choice

How does heat flow?

• Always from cold to warm
• Always from warm to cold
• Both warm to cold & cold to warm
• It depends on the temperature

Multiple Choice

The specific heat of water is 4.18 J/g°C.

If 980. J of energy is added to 6.20 g of water at 18.0 °C, what is the final temperature of the water?

• -55.8 °C

• -19.8 °C

• 19.8 °C

• 55.8 °C

Multiple Choice

Lighting a match produces heat (energy) as the match stick burns. This is an example of an ____________ reaction.

• endothermic

• exothermic

Multiple Choice

Is the process shown to the right exothermic or endothermic?

• endothermic

• exothermic