post has two assignments
1. For the following binary compounds
Midterm Exam 2. Practice problems
a) Sort compounds on two groups –
ionic compounds and molecular compounds (compounds with covalent bonding)
b) Provide formulas for both groups (remember: there are different rules for naming ionic and covalent compounds)
sodium iodide _____________________________________
magnesium oxide _____________________________________
silicon tetrachloride _____________________________________
sulfur dioxide _____________________________________
diphosphorus pentoxide _____________________________________
calcium fluoride _____________________________________
lithium oxide _____________________________________
carbon tetrafluoride _____________________________________
2. Provide names for the following compounds:
a) Ionic
KI _____________________________________________
CaO _____________________________________________
MgBr2 _____________________________________________
Na2O _____________________________________________
b) molecular (covalent)
SF6 _____________________________________________
P2O5 _____________________________________________
NO3 _____________________________________________
N2O5 _____________________________________________
3. Complete following reactions and:
a) Use your knowledge of octet rule to find out the formula of the product. Indicate the charge on each ion (it will help you to decide what subscripts you need for each element).
b) Balance the reaction.
Na + O2è
K2O + H2O è
Ca + O2è
MgO + H2O è
4. Consider the reaction:
2S + 3O2è 2SO3
Following questions are independent from each other
a)How many moles of SO3 will be formed if there are 2.3 moles of O2 and sulfur is present in excess?
b) How many moles of each reactant (S and O2) do you need to get 6 moles of SO3?
c) How many grams of SO3 will be formed from 41g of S if oxygen is in excess?
d) This reaction was performed with 64 g of S and 64 g of O2.
d1)What was the limiting reactant in this case?
d2)What was the theoretical yield?
d3)What was the percent yield if there were 60 g of SO3 collected?
5.Draw a Lewis structure for the molecule of water (H2O), the molecule of methane(CH4), and the molecule of ammonia (NH3). Remember to obey the octet rule. Mark lone pairs on the Lewis structure.
6. Write the reaction of oxidation of Na by Cl using a Lewis structure
Na + Cl è NaCl
7. True or false:
a) Covalent bondinginvolves the transfer of valence electrons from one atom to another atom
b) in the compounds with ionic bonding elements hold together by Coulombic force.
c)An ionic bond is formed when two atoms share one or more pairs of electrons.
d) When atoms share two electron pairs it is called the double bond.
e) The valence electrons which don’t participate in the covalent bond are called the lone pairs.
9. For the following elements : Na, F, Mg, S
a) draw the Lewis structure for each element and determine how many electrons should be gained or lost according to the octet rule.
d) For each element indicate what kind of ion is formed. (Hint: how do we call a negatively charged ion? a positively charged ion?) Indicate the charge of the ion.
10. True or false:
a) Ionization energy is the energy required to remove one electron from the atom.
b) the atomic radius decreasing when going down a group in the periodic table.
c) the elements of the groupVII in the periodic table are metals
11. Write the formulas of the following compounds.
Aluminum sulfate _________________________________
Sodium carbonate _________________________________
Ammonium hydroxide _________________________________
Potassium phosphate _________________________________
12. Write the names of the following compounds.
K2CO3 __________________________________
NaOH __________________________________
KNO3 __________________________________
MgSO4 __________________________________
2:Federal government
It is a fact that the federal government (1) encouraged the development of the savings and loan industry, (2) virtually forced the industry to make long-term fixed-interest-rate mortgages, and (3) forced the savings and loans to obtain most of their capital as deposits that were withdrawable on demand.
Would the savings and loans have higher profits in a world with a “normal” or an inverted yield curve? Explain your answer.
Would the savings and loan industry be better off if the individual institutions sold their mortgages to federal agencies and then collected servicing fees or if the institutions held the mortgages that they originated?
binary compounds