1
Write the formula and compound name for the following:
Fe3+ + O2-
Formula: Fe2O3
Name: Iron(III) oxide
Using the crossing rule, You can cross the 2 and 3 and make Fe2 and O3. We know that Fe is a transition metal and in the equation it is given that the Fe has a charge of 3. So while naming the compound you have to specify Irons charge in roman numerals. Since it's an ionic compound, the nonmetal will end in an “ide”. Hence oxide. Final answer will be Iron (III) oxide.
What is the formula for tin (II) phosphate?
Sn3(PO4)2
We know that Phosphate is a polyatomic ion. We also know that tin has a charge of 2 in this equation. Phosphate’s charge is a negative 3. Using this information you can use the crossing method and arrive at the answer Sn3(PO4)
Given the chemical formula, determine the name for N2O3
Dinitrogen trioxide
There are 2 nitrogen molecules so the prefix for nitrogen is di. There are 3 oxygen molecules, so the prefix for oxygen would be tri. Since oxygen is the last element, it will also end in ide.
The final name would be Dinitrogen trioxide
How many molecules of NO3 (Nitrate) need to be present for the molar mass to be 186g/mol?
1
4
3
5
3
THe molar mass of NO3 alone is about 62g/mol. Now divide 186 by 62. 186/62 = 3. Therefore there needs to be three sets of NO3 for the molar mass to be 186.
(NO3)3 = 186g/mol.
A student was taking a test and was told to write a correctly balanced chemical equation. The student wrote this:
2Al + 3O → Al2O3
What is wrong with this equation?
the equation should be 4Al +3 O2→ 2Al2O3
Oxygen is one of the diatomic elements. It can only be written as O2 when it is by itself. It can never be by itself as a single atom.
Ron was doing a chemistry experiment. While conducting the experiment he noticed that the boiling point of the substance was really high. The teacher told him to identify whether the substance was made from covalent or ionic bonds. What was most likely Ron's answer?
Ionic
Ionic bonds are made up of metals and nonmetals. They usually tend to have high boiling and melting points. (also mentioned in slide 4 of notes)
Monty was asked to find the chemical formula of lithium telluride. Help Monty out by choosing the correct answer.
LiTe
LT
LiT2
Li2Te
d. Li2Te
We first need to find the chemical symbol and charge of each element. Looking at the periodic table, Lithium (Li) has a charge of -1. Telluride (Te) has a charge of 2+ because it is in group 16. Now using the cross method, we can determine the subscripts for each element. This ultimately gives is Li2Te.
What is the product of this?
AgNO3 + KCl → AgCl + KNO3
AgNO3 + KCl → AgCl + KNO3
In double replacement, the cations switch places with each other. In this equation, theAg and K switch places with each other. Then the elements need to be criss crossed again to see if the subscripts need to change. SInce the Ag has a charge of +1 and Cl has a charge of -1 its AgCl, since K has a charge of+1 and NO3 has a charge of -1 it is KNO3
Zn + CuBr2 → ?
ZnBr2 + Cu
In a single replacement one element in the compound is replaced by another. First determine if you can switch Zn and Cu. In the activity series Zinc is higher than copper, therefore it can replace cu. Now you have to use the criss cross method to write the correct subscripts. SInce Zn has a charge of +2 and Br has a charge of -1, it would be written as ZnBr2. Since Cu is not a diatomic element, it stays alone.
Identify what type of chemical reaction this is:
2 KClO2 → 2 KCl + 3 O2
synthesis
decomposition
single replacement
double replacement
combustion
2. decomposition
In decomposition, one reactant forms more than one product. Thats what happened in this reaction as well.
BALANCE THIS EQUATION:
hydrochloric acid + calcium carbonate → calcium chloride + carbon dioxide + water
(HCl + CaCO3 → CaCl2 + CO2 + H2O)
HCl + 2CaCO3 → CaCl2 +CO2 +H2O
Reactants Products
Ca 1 1
C 1 1
O 3 3
H 1 2
Cl 1 2
The only thing different in the products side was the number of Hydrogen and Chlorine atoms, so if you add a 2 in front of the HCL in the reactants side, now both sides have the same amount and it is balanced.
Describe the Lewis Dot structure for N2
First note that nitrogen is the only diatomic molecule with triple bonds. Since covalent bonds share electrons, the three pairs of electrons are in the middle for both the nitrogen's. There is also one set towards the side of each nitrogen. In total, each nitrogen has a full shell of valence electrons.
Nick’s chemistry project requires him to identify the properties of ionic compounds. Nick wasn't paying attention in class, so he went and asked the teacher for help. The teacher agreed to help him. What would have likely been the teacher's response?
ionic bonds are weak and brittle
ionic compounds have a low melting point and a low boiling point
ionic compounds are hard, and rigid
there are no significant properties of ionic compounds
c. ionic compounds are hard and rigid
Ionic bonds are arranged in a crystal lattice form. This makes them strong and hard to break apart. Due to this they are usually very rigid, hard, and have high boiling and melting points.
Determine the shape, and draw or describe the VSEPR model for the compound: Carbon tetrachloride
The structure of CCl4 is a tetrahedral because it has 4 atoms bonded to the central atom and zero lone pairs around the central atom. The structure consists of a single bond between each chlorine atom and the central atom, and 6 dots around Cl’s. This gives all the atoms 8 valence electrons.
What type of reaction is this?
CH4 + 2O2 → CO2 + 2H2O
Combustion
Double replacement
Single replacement
Combustion
slide 12 in chemical reaction notes.
French chemist named Antoine Lavoisier conducted experiments in a sealed jar. Because the total mass of the jar and its contents was the same after the reaction as it was before the reaction took place, he discovered the law of conservation of mass.
Why was it important to conduct the experiment in a sealed jar?
Sealing the jar was important for the experiment because he wanted to see if the contents would be the same or not after the reaction.
The law of conservation of mass states that mass cannot be created or destroyed. In order to test whether mass can be created or destroyed it was important to seal the jar. If the jar was not sealed, then gases could have escaped or come into the jar, ruining the purpose of the experiment.
Gilbert Lewis’s ___________ states that when forming a compound, atoms usually tend to achieve the electron configuration of a noble gas.
Electron dot structures
group 8
valence electrons
octet rule
d. Octet rule
The octet rule does infact state that atoms tend to form compounds in ways that will give them 8 valence electrons (full outer shell). Noble gasses have full outer shells, therefore when a compound is made, its electron configuration is similar to that of a noble gas.
Determine the molar mass of CO2
44.01
1C = 1(12.01)
2O = 2(16) = 32
32+12.01 = 44.01
Balance this equation:
S + HNO3 → H2SO4 + NO2 + H2O
S + 6 HNO3 → H2SO4 + 6 NO2 + 2 H2O
reactants products
S 1 1
H 1 4
N 1 1
O 3 7
Since S is already the same on both sides, no need to add a coefficient. SInce there is more Oxygen in the products side, the coef. of 6 on the reactants side would make the oxygen 18. Then the coef. 2 and 6 on the products side will make the oxygen 18. After balancing:
reactants products
S 1 1
H 6 6
N 6 6
O 18 18
Which statement correctly states what happens when a metal and nonmetal are combined to form a binary compound?
the metal forms an anion(-) and the nonmetal forms a cation(+)
both the metal and non metal form cations(+)
the metal forms a cation(+) and the nonmetal forms an anion(-)
both the metal and nonmetal form an anion(-)
c. the metal forms a cation and the nonmetal forms an anion
When these binary compounds(metal +nonmetal) are made, the metals lose electrons, making them cations. The nonmetals gain electrons, which is an anion.