Chem 1510 SI Keith Week 4 Session 3

1. The current world record holder for the fastest time in the 200. meter dash is Usain Bolt, with a corrected time of 19.19 seconds. 1 mi = 1, 609 m 1 m = 3.281 ft

a. What is his average velocity in m/s?

b. How many feet can he travel in 5.00 seconds at this velocity?

c. What is his average velocity in miles per hour (mi/hr)?

2. Epinephrine has the formula C9H13O3N. How many carbon atoms are present in 1.00 g of epinephrine?

3. A 4.450 g sample of hydrated lithium iodide, LiI . xH2O, is dried in an oven. When the anhydrous LiI salt is removed from the oven, its mass is 3.170 g. What is the value of “x”?

4. A 12.000 g sample of a compound with generic formula CxHyOz undergoes combustion to

give 15.222 g of CO2 and 4.158 g of H2O. Calculate the empirical formula of the compound. 5. One of the steps in the commercial process for converting ammonia to nitric acid is the

conversion of NH3 to NO:

4NH3(g) + 5O2 (g) → 4NO(g) + 6H2O(g)

In a certain experiment, 2.25 g of NH3 reacts with 3.75 g of O2.

a. How many grams of NO form?

b. How many grams of excess reactant remain after the limiting reactant is completely consumed?

6. When 100.0 kg of sand (SiO2) is processed via the reaction below, only 51.4 kg of SiC are recovered. What is the percent yield of this process?

SiO2 (s) + 3C(s) → SiC(s) + 2CO(g)