chem lab final 1 + 2

Which of the graphs below most closely describes the behavior of a pure liquid as it undergoes freezing? The y-axis is temperature and the x axis is time.

Graph C (starts high, dips down, levels out into a straight line)

Which of the following is an example of an alkaline earth halide?

MgBr2

Magnesium metal (0.100 mol) and a volume of aqueous hydrochloric acid that contains 0.500 mol of HCl are combined and react to completion. How many liters of hydrogen gas, measured at 0 C and 760 torr, are produced?

2.24 L of H2

A calorimeter contains 50.0 g of water at 20.0 C. A 1.000-g piece of metal is heated to 100.0 C and then placed in the water in the calorimeter. After stirring, the final temperature of both metal and water is 25.0C. what is the specific heat capacity of the metal? Assume that no heat is lost to the calorimeter of the surroundings.

13.9 J/gC

Nitric oxide reacts with chlorine to form nitrosyl chloride 2NO(g) + Cl2(g) → 2NOCl(g)

Use the following data to determine the rate constant for the reaction

37.8 Ms

You analyzed the comp of al/zinc alloy by reacting a sample of the alloy w hydrochloric acid. According to the balanced net ionic equation for this reaction, how many moles of hydrogen gas are produced for every two moles of aluminum in this sample?

3

In the reaction Y + X^- → Y^- + X
which of the species is the oxidizing agent?

Y

100 mL of water is placed in the calorimeter. The initial temperature was 24.6C. An ionic solid (1.00 g) was added to the water. After the solid dissolved the final temperature of the solution was 26.3C. What type of process is the dissolving of the solid?

both a and c above

From the graph below, estimate the normal boiling point for t-butanol

85 C

the moloecular mass of a substance was determined by the freezing-point depression technique. The MINIMUM data required for the determination are

delta T, Kr, mass of solute, and mass of solvent

In the titration of a solid acid with sodium hydroxide, the phenolphthalein indicator first changed color

at or very near the equivalence point

Which one of the following statements regarding halogens (group) is false?

They give up electrons readily to form cations

Which of the following statements about the thiosulfate clock reaction is false?

The rate constant can be obtained from the slope of a straight line plot of Ea vs. 1/T

Consider the following specific heat capacities of some metals

sodium 1.23 J/(g C)
chromium 0.447 J/(g C)
lithium 3.56 J/(g C)
cobalt 0.418 J/(g C)
nickel 0.444 J/(g C)
If the same amt. of heat is added to 200-g samples of each of the metals, all initially at the same temperature, which will have the highest temperature?

cobalt