#1

Question 1  : 

A fictional element has two isotopes and a molar mass of 82.58 g/mol. The first isotope has an atomic mass of 81.09 u and 27.63 % of the element’s atoms are this isotope. What is the atomic mass (in u) of the second isotope? 

Question 2  : 

What mass (in g) of butanol (C4H10O) is required such that its combustion produces 66.7 g of products? The combustion of a compound (containing C, H, and O) is its reaction with molecular oxygen (O2) to produce water and carbon dioxide. 

Question 3  : 

329.2 g of SO2(g), 411.7 g of CaCO3(s), and 115.9 g of O2(g) react in the following fashion: 

2 SO2(g) + 2 CaCO3(s) + O2(g) —> 2 CaSO4(s) + 2 CO2(g)

What mass (in g) of CaSO4(s) can be produced?

#2

Question 1  : 

We have a container enclosing a mixture of N2(g) and O2(g). The total pressure is 4.11 atm. The temperature is 25.00 oC and the volume of the container is 19.8 L. If the mass of N2 in the container is 37.5 g, what is the partial pressure of O2 (in atm) within the container? 

Question 2  : 

The density of a sample of NH3(g) at a pressure of 1.00 atm is 0.925 g/L. What is the root-mean-square speed (in m/s) of the molecules in this sample? 

Question 3  : 

In a 5.00 L steel container at 575 K, the partial pressures of H2(g) and O2(g) are respectively 20.89 and 13.88 atm. The H2(g) and the O2(g) react together to produce H2O(g). The final temperature remains at 575 K and the volume remains at 5.00 L. What is the final total pressure (in atm)?