Chemistry

The following problems are due on Wednesday October 8.
I.	(16pts – 8 pts each part). Balance the following equations by inspection.

i.	Al(s)   +  NH4ClO4                                            	Al2O3  + AlCl3  + NO  +  H2O	
ii.	KO2     +   H2O  + CO2                                              KHCO3   +  O2

II.	(20pts)  4Na2PO3F  is a component in a fluoride dentifrice. A decomposition reactions:

4Na2PO3F                                       8Na(s) + P4(s)   +   6O2(g)  +  2F2(g)

(a)	How many grams of O2 gas can be produced from 0.0350 milligrams of Na2PO3F?
(b)	How many moles of Na(s) can be produced when the decomposition in (a) above occurs?

III.	(49pts) Consider the reaction
Al2(SO4)3(aq)   +  6NaOH(aq) 	3Na2SO4(aq)  +  2Al(OH)3(s)
If 8.44g of Al2(SO4)3 are mixed with 17.233g of NaOH and the reaction is run, answer the following questions:
a)	(15pts) what is the limiting agent?
b)	(10pts) assuming no side reactions, how much Na2SO4 can be produced under these conditions?
c)	(9pts) if 6.52g of Na2SO4 are produced in the lab, what is the percentage yield?
Data: Atomic mass Na = 22.99, O = 16.00, H = 1.008, Al = 26.98, S = 32.07
IV.	(15pts) A cube of platinum weighs 64.8g and its density is 21.5g/cm3. Calculate:
a)	The volume of the sample
b)	The number of platinum atoms in the sample
If we consider the sample as composed of spherical atoms each with a radius r and volume 
Vatom = 4/3?r3, and if we assume that the total number of spheres in the sample is 74% of the total volume of the sample, calculate the radius of a single platinum atom in Pico-meters.
Bonus Problem:  3 pts No partial credit. Search the WEB for a site that allows you to balance equations, and use the site to balance the following reaction. Note that both materials and charges must balance.
	CO2(g)  +  NH4+   +   O2                                  C5H7O2N  +  NO2-  +  H2O  +  H+