Lewis Structures and Geometry
Based on the octet rule, many electrons do we expect each atom to have in a completed Lewis Structure?
8 electrons (octet rule)
What type of reaction is the following:
2Na(s) + 2H2O(l) --> 2NaOH(aq) + H2(g)
Single replacement
The metric prefix kilo is equivalent to what numerical value
1000
True or False: Heat of a reaction is measured in units of Kelvin
False. Heat is a unit of energy, so heat of a reaction should be measured in Joules (or kiloJoules) per mole
A compound made up of a nonmetal and a nonmetal is a what compound?
A covalent compound
What is the formula for density?
"Mass"/"Volume"
What is the geometry of chlorine, Cl2?
linear
If the reaction below is balanced using the smallest whole number coefficients, the coefficient in front of Fe is:
___ Fe(s) + ___O2(g) --> ____Fe2O3(s)
4
Convert 0.269mL into liters
0.000269 L (2.69*10-4 L)
If an endothermic process absorbs +100 J of heat, the change in heat for its surroundings must be:
-100 J of heat
-NaF
-H2S
-carbon dioxide
-dinitrogen monoxide
NaF (sodium fluoride)
3 significant figures
Explain why N is located at the center of the structure in the Lewis Structure of N2O instead of O
Because N has lower electronegativity and is therefore more willing to share its electrons
Which law explains why chemical reactions must be balanced?
The Law of Conservation of Matter
What value needs to be used to determine the number of atoms of gold in 0.20 mol of gold?
6.022*1023 particles/mol
In the process below, would we expect heat to be a product or reactant?
H2O(s) --> H2O(l)
CCl4
How many pairs of unbonded electrons would we expect on the central N in NH3?
1 pair of unbonded electrons
What must be true of at least one of the products of a double replacement reaction in order for the reaction to occur?
At least one of the products must be a solid, liquid, or gas
The reactant that determines the amount of product that will be formed in a reaction that goes to completion is the
Limiting reactant
A reaction that is exothermic is one where the heat of the products is ______ the heat of the reactants
less than
Give the formula for magnesium carbonate
MgCO3
A polar covalent bond is one in which electrons are
Determine the geometry of the molecule O3, ozone
bent
Predict the products for the following reaction:
C4H10(l)+O2(g)-->
CO2(g) + H2O(l)
What is the theoretical yield of a reaction that actually produced 5.00g of product and had a percent yield of 93.6%?
5.34g
Decomposition reactions are often endothermic because:
They involve the breaking of bonds, which requires energy
Give the name of the compound CH4
Methane
How many unbonded pairs of electrons would we expect a molecular with a tetrahedral geometry to have?
0 pairs
Which of the following molecules is polar? (all bonds are polar except C-H and N-N)
CF4
N2
BCl3
CH2F2
CH2F2
Which of the following single replacement reactions will NOT occur:
Mg(s) + AgNO3(aq)-->
Cu(s) + AgNO3(aq)-->
Au(s) + AgNO3(aq)-->
Fe(s) + AgNO3(aq)-->
Au(s) + AgNO3(aq)-->
Gold (Au) is less reactive than silver (Ag), so the reaction does not occur
Write the set up to solve for the molarity of a solution of substance A if substance A has a molar mass of X g/mol and Y g of substance A is dissolved to make Z mL of solution.
Y g * (mol)/(X g) *1/(Z mL) * (1000mL)/(L
Consider the following thermochemical equation:
2H2(g) + O2(g) --> 2H2O(g) ∆H = -571.6kJ/mol
How much heat is produced for every ONE mole of H2 reacted?
-285.8 of heat are released per mole of H2 reacted
Give the name of the compound Fe3(PO4)2
Iron(II) Phosphate
Water
Carbon Dioxide
Ammonia
Sulfur Dioxide
carbon dioxide