An element has three stable isotopes with masses of 27.977 amu, 28.976 amu, and 29.973 amu. The heavier two isotopes have an abundance of 4.68% and 3.09%, respectively. What is the mass of the element? (Hint: There is 100% total for all three)

Which of the compounds C3H8, MgCl2, Zn(NO3)2, OCl2 are expected to exist as molecules?

Chromium (Cr) is used in many engineering applications, to harden steel and make other metal alloys. The density of chromium is 7.2 g/cm3.  How many moles of chromium are there in a 1 cm3 cube of chromium (to 2 decimal places)?

Which of the following is the highest grossing film of all time in America?

One of the components in gasoline is octane. When octane undergoes combustion in an internal combustion engine, what describes q and ΔH?

You have probably heard enough about this already but learning how to learn in this course is just as important as the content. What we are telling you isn’t stuff we just made it, it is based on the latest research in teaching and learning. It is a myth that people learn different ways, at least in the context of subjects like general chemistry. Howard Gardner has described a theory of multiple intelligences, but this is controversial, and in general chemistry there really is only one way that students learn. All students need to construct their own understanding of the material by working with it, seeing different concepts in multiple contexts, this is described in the theory known as contructivism: This course is based on these ideas. You are given the opportunity to work with different concepts in many different contexts in the Learning Activities, assuming that you actually take them seriously! So, use the Learning Activities to construct your understanding of the material, and build your ability to solve problems, then, use the practice exams to do what?

Ethanol, CH3CH2OH, is a renewable, liquid fuel commonly made from plant materials such as corn, sugar cane, or grasses. It is also known as ethyl alcohol or grain alcohol. Ethanol is also frequently added to gasoline to make a mixture of ethanol and gasoline, called “oxygenated gasoline”. The oxygen in the formula provides more immediate oxygen during combustion, providing for more complete combustion and lower carbon monoxide emissions.When ethanol is added to gasoline, the two liquids never become unmixed again, What is the entropy explanation for this?

One of the main sources of energy you body uses is glucose. The body extracts energy from glucose in the following chemical reaction known as aerobic respiration: C6H12O6 (s)    +    6 O2 (g)        →        6 CO2 (g)      +      6 H2O (l)    +  32 ATP    glucose     +       oxygen                carbon dioxide  +     water If you were to burn/combust glucose in air (yes, it can be burned!), the chemical equation would be very similar: C6H12O6 (s)    +    6 O2 (g)        →        6 CO2 (g)      +      6 H2O (l)      glucose     +       oxygen                carbon dioxide  +     water Both of these processes have overall negative ΔHr, meaning they are both exothermic, both release energy in the form of heat. Which one would you expect to be the most exothermic, which would release the most energy in the form of heat?

Determine ΔG for the following redox reaction to determine if it will be spontaneous or not: Fe(s) + 2 H+ (aq) → Fe2+(aq) + H2(g) Use the following half reaction data from tables to answer this question. You will need to obtain Eox from one of the Ered values. 2 H+(aq)  +  2e-  →  H2(g)               Ered = 0.0 V (this is the SHE reaction, it is 0 V by definition) Fe2+(aq)  +  2e-   →   Fe(s)               Ered = -0.44 V              ΔG = -n F Ecell F = 96,485 Coulombs/mol

In an automobile engine, nitrogen gas N2, can react with oxygen gas, O2, to form nitrous oxide, N2O. This balanced equation for this process is shown below. Use Le Chatelier’s Principle to determine which of the following will cause the equilibrium to shift right, i.e. towards the products, N2O. 2 N2(g)  +  O2(g)    ⇌   2 N2O(g)