Homework #18

2CAS #1-12


1. The law of conservation of matter is that matter cannot be created nor destroyed. 


2. Scientific law summarizes what has been learned by careful observation of nature.

3. Those expressions can be interpreted as confusing because molecules can be converted and decomposed by chemical processes, but atoms are forever, and are not "used up" or "thrown away."


4. 
a. Not balanced.
Reactant side: Sn, 1; H, 1; F, 1
Product side: Sn, 1; H, 2; F; 2
b. Not balanced. 
Reactant side: Si, 1; O, 2; C, 1
Product side: Si, 1; O, 1; C, 2
c. Balanced. 
Reactant side: Al, 1; O, 3; H, 6; Cl, 3
Product side: Al, 1; O, 3; H, 6; Cl, 3

5. a. 3
    b. 2 
    c. 1 


6. See on paper.


7. a. 1 Ca3(PO4)2 + 3 H2SO4 --> 2 H3PO4 + 3 CaSO4
    b. 2 C8H18 + 25 O2 --> 16 CO2 + 18 H2O

8. 

a. Yes. 

Reactant side: Na, 2; S, 1; O, 4; K, 2; Cl, 1
Product side: Na, 2; S, 1; O, 4; K, 2; Cl, 1
b. No. Although the subscripts remained the same, the coefficients have been altered. 
c. 1 Na2SO4 + 2 KCl --> 2 NaCl + 1 K2SO4

9. ?

10. 

a. 32g
b. 48g
c. 100g
d. 58g
e. 180g

11. Although copper and sodium have different masses, volumes, and densities, the weight of each atom per mole remains the same. 

12. 

a. 1 
b. 0.5 
c. 0.1 
d. .3