Chemistry Exam 1

Which term best describes the following? There is only one correct answer.
Diamond (consisting of only carbon) is ______(i)___________, the transparent gemstone sapphire (aluminum oxide with other trace minerals present) is _______(ii)______________ and sucrose (table sugar) is _______(iii)_________.

Which of the following answers is written properly with regard to significant figures for the following calculation:
(21.45-19.6)
-----------------
28.5

Consider the following processes:
(i) making Kool-Aid by dissolving Kool-Aid mix and sugar in water.
(ii) carbonating water by pressurization with carbon dioxide
(iii) corrosion of metal on your car
(iv) burning your chemistry textbook
(v) condensation of water vapor from your breath on a mirror

Which of these processes are correctly referred to as a "physical change"?

You have a piece of gold with a mass of 483.0 grams. You have a graduated cylinder containing 50.0 mL of water. You add the piece of gold to the graduated cylinder, it sinks to the bottom and the water level rises to read 75.0 mL. What is the density of the gold.

1.00 g/cm^3 equals ____________ kg/m^3.

An elemental ion has 34 protons, 36 electrons, and 44 neutrons. What isotope is it?

The Rutherford experiment, in which thin gold foil was bombarded with alpha particles (helium nuclei) showed that:

The best name for H2Se when it is classified as an acid is ______(i)_______; the best name for N2F4 is ________(ii)______; and the best name for Mg3As2 is ______(iii)__________.

Which group of elements is most likely to gain two electrons to form a stable ion?

If perbromic acid has the formula HBrO4, what is the formula for bromous acid?

For the combustion of the hydrocarbon octane (C8H18) in air, what is the coefficient in front of O2 when the chemical equation for the reaction is properly balanced?

Determine the formula weight for ammonium carbonate.

How many moles of glucose C6H12O6 are present in 100.0 grams of glucose?

How many total atoms are present in 0.150 moles of acetic acid, C2H4O2?

Butyric acid is responsible for the rancid odor you smell when certain foods decompose. Butyric acid is composed of 54.53% C, 9.152%H and 36.32% O by mass. What is the empirical formula for butyric acid?

Given the balanced chemical equation and chemical formulas for the combustion of butane:
2C4H10 + 13O2 --> 8CO2 + 10H2O

Glucose is your body's preferred energy source. Your body burns glucose in a series of reactions that add together to give the net reaction for glucose combustion show below:

C6H12O6 + 6O2 --> 6CO2 + 6H2O

You expel CO2 produced from this process each time you breathe out. How many grams of CO2 will be produced from the complete metabolism (combustion) of 355 grams of glucose?

If 4.0 moles of Fe and 6.0 moles of O2 are used in the reaction 4Fe + 2O2 --> 2Fe2O3, then the limiting reactant is __________________ and the theoretical yield of Fe2O3 is ____________________ mol.

If you dissolve 0.30 moles of ammonium nitrate in 0.70 liters of solution, what is the total concentration, in moles/liter, of all of the ions present in solution?

What are the spectator ion(s) for the reaction of the /insoluble salt/ "milk of magnesia", Mg(OH)2, with hydrochloric acid in your stomach.

What mass of potassium chloride is needed to prepare 0.750 liters of a 0.250 M KCl solution?

Which class of reaction is the following reaction best described by?
BaCl2(aq) + Na2SO4(aq) --> BaSO4(s) + 2NaCl(aq)

You have 250.0 mL of 6.00 M NaOH which you dilute to a final volume of 1.75 liters by adding water. What is the new concentration of NaOH in the diluted solution?

Which of the following are correctly referred to as "extensive properties"?
(i) mass of a substance
(ii) mols of a substance
(iii) density of a substance
(iv) molarity of a substance
(v) volume of a substance

When the following calculation is performed properly, how many significant figures should be reported in the answer?
(99.31 + 0.754)
---------------------
155.81

Which of the following scientific observations supports the following statement: "Lime is not an element".

How many mL of mercury with a density of 13.6 g/mL will have the same mass as 50.0 mL of hexane with a density of 0.655 g/mL?

1.0 kg/cm^3 equals _______________ ug/m^3

What is the correct formula for the species that has 44 protons, 56 neutrons and 42 electrons?

For neutral atoms which statement is CORRECT?

The best name for N2O4 is _____(i)________; the best name for Al2S3 is __________(ii)________; and the best name for NiCl2 is ______(iii)_________.

Which of the following should be the most similar in chemical property to strontium (Sr)?

When named as an acid, H2CO3 is called:

For the combustion of the hydrocarbon hexane (C6H14) in air, what is the coefficient in front of H2O when the chemical equation for the reaction is properly balanced?

Determine the formula weight for calcium nitrate.

How many moles of glycerol, C3H8O3, are present in 415 g of glycerol?

Acetone, formula C3H6O is an organic compound found in some solvents, and is also produced by the body during starvation and in uncontrolled diabetes. How many hydrogen atoms are present in 50.0 grams of acetone?

Mothballs are made of naphthalene, a C and H containing compound. The mass % of C in naphthalene is 93.71%, while the mass % of H is 6.29%. What is the empirical formula for naphthalene?

For the combustion of hydrogen and oxygen gases:

2H2 + O2 --> 2H2O

How many moles of O2 are required to produce 7.0 moles of H2O?

A simple way to prepare oxygen in the laboratory is by the decomposition of potassium chlorate, which occurs upon heating:

2KClO3(s) --> 3O2(g) + 2KCl(s)

Assuming the reaction goes to completion, if 10.0 grams of KClO3 are decomposed according to the balanced chemical equations shown above, what mass of O2 will be produced?

If 4.0 moles of Li and 2.0 moles of O2 are used in the reaction 4Li + O2 --> 2Li2O, then the limiting reactant is ________________ and the theoretical yield of Li2O is ___________________ mol.

If you dissolve 0.75 moles of ammonium nitrate in 0.50 liters of solution, what is the total concentration, in moles/liter, of all the ions present in the solution?

Nitrate salts are soluble, as are salts that contain a group 1A (alkali metal) ion. Silver carbonate is an insoluble salt. What is/are the spectator ion(s) for the reaction that occurs when solutions of silver nitrate and sodium carbonate are mixed? from the list below.

What mass of potassium chloride is needed to prepare 0.750 liters of a 0.250M KCl solution?

Which class of reaction is the following reaction best described by?

Ni(s) + 2HClO4(aq) --> H2(g) + Ni(ClO4)2 (aq)

Dilute solutions of acids are commonly prepared by diluting the concentrated commercial stock solutions of HCl found in chemistry laboratories. The concentration of stock HCl is 12 M. What volume of 12 M HCl should be diluted to 0.50 L with water in order to have a 0.25 M solution of HCl?