Chemistry 104 Final
Which symbol, often found in chemical equations, indicates that a substance is dissolved in water?
(aq)
1 milligram is equivalent to how many grams?
0.001
How many moles of KCl are present in 50.0 mL of a 0.552 M solution?
0.0276 mol
If 5.20 g of HCl is added to enough distilled water to form 3.00 L of solution, what is the molarity of the solution? [Molecular weight: HCl, 36.46 amu]
0.0475 M
What is the molarity of a solution if 300.0 mL of it contains 16.8 g of KNO3? [Formula weight: KNO3, 101.11 amu]
0.554 M
A solution contains 1.65 g of NaF in a total volume of 150.0 mL. What is its concentration expressed as % (m/V)?
1.10%
A sample of aluminum contains 2.91 × 1022 atoms of aluminum. What is the mass of this sample? [Molar mass: Al, 26.98 g/mol]
1.30 g
A typical aspirin tablet contains 5.00 grains of pure aspirin analgesic compound. The rest of the tablet is starch. How many aspirin tablets can be made from 50.0 g of pure aspirin? [Use: 1.00 g = 15.4 grains]
154 tablets
What is the mass of 4.00 moles of helium, the gas commonly used to fill party balloons and lighter-than-air ships?
16.0 g
The chemical equation below is unbalanced. What is the coefficient of water when the equation is balanced? Mg(OH)2(s) + HCl(g) → MgCl2(s) + H2O(l)
2
What is the mass of one mole of diatomic hydrogen, H2?
2.02 g
How many grams of KCl are present in 250.0 mL of a 0.125 M solution? [Molar mass: KCl, 74.55 g/mol]
2.33 g KCl
What mass of glucose is contained in 500.0 mL of a 5.00% (m/V) solution?
25.0 g
Which of the following best represents the autoionization, or self-ionization, of water?
2H2O(l)H3O+(aq) + OH-(aq)
Which notation properly indicates how two molecules of diatomic oxygen would be represented in a chemical equation?
2O2
How many molecules of water are present in a 5.65 mole sample of water?
3.40 x 10^24 molecules
The mass of one atom of oxygen is 16.00 amu. What is the mass of one mole of elemental oxygen (O2)?
32.00 g
A buffer solution contains acetic acid (HC2H3O2) at a concentration of 0.225 M and sodium acetate (NaC2H3O2) at a concentration of 0.164 M. The value of Ka for acetic acid is 1.75 × 10−5. What is the pH of this buffer solution?
4.62
At 100°C, which gas sample exerts the greatest pressure?
A
Which statement correctly describes conjugate acids and bases according to the Brønsted-Lowry theory?
A conjugate base is the species formed when an acid donates a proton; a conjugate acid is the species formed when a base accepts a proton
Formic acid (HCO2H) is a weak acid found in the venom of bees and ant stings. Which of the following is an accurate statement concerning an aqueous solution of formic acid? HCO2H(aq) + H2O(l)H3O+(aq) + HCO2−(aq) Ka = 1.8 × 10−4
A formic acid solution predominantly contains undissociated HCO2H molecules
Which statement concerning the scientific method is FALSE?
A hypothesis becomes a theory when a single experiment supports it
Which statement about chemical bonds is FALSE?
A non-polar covalent bond is one in which electrons are not shared equally between the atoms
What statement best describes an intensive property?
A property of a substance that does not depends on the quantity of the substance present
Which statement concerning solution concentration is FALSE?
A saturated solution contains more than 100 g of dissolved solute
Which statement concerning solutions is FALSE?
A solution forms when the solvent and the solute react to form a new substance with one uniform phase
Which of the following properly describes a colligative property of a solution?
A solution property that depends on the concentration of a solute particles present
Which statement concerning the classification of matter is FALSE?
All matter is either pure substance or a compound
What is the name of the ion NH4+?
Ammonium
Consider the following generalized buffer solution equilibrium: BH+(aq) + H2O(l) H3O+(aq) + B(aq) When a small amount of a strong base such as sodium hydroxide is added to the solution, which of the four species shown would experience an increase in concentration? (Hint: Use LeChatelier's principle.)
B
. A molecule of deoxyribose, an essential part of DNA, contains five carbon atoms, ten hydrogen atoms, and four oxygen atoms. How would the formula of deoxyribose be represented?
C5H10O4-numbers to the bottom
What is the formula of the ionic compound formed when ions of calcium and nitrogen combine?
Ca3N2
Which statement about compounds is FALSE?
Covalent compounds are composed of metals and nonmetals
Considering the electronegativity values indicated in the table, which covalent bond is the most polar?
H-F
Which gas under the specified conditions would come closest to exhibiting ideal gas behavior?
H2 at low pressure and high temperature
A particular buffer solution consists of a weak acid and its conjugate base. How could this buffer solution be modified so as to increase its buffer capacity against added base?
Increase the concentration of the weak acid
When a molecule is hit by gamma radiation, which of the following is likely to occur?
Ionization
Which statement explains why isotopes have different mass numbers?
Isotopes differ in number of neutrons each contains
What is TRUE about a solution whose pH is less than 7?
It has a hydronium ion concentration that is higher than pure water itself
Two molecules of ethane experience what type of attractive forces?
London dispersion forces
Which statement best describes the Law of Conservation of Mass?
Matter is neither gained nor lost in a chemical reaction
Which statement concerning changes in matter is FALSE?
Melting and freezing are chemical changes that change both the appearance of the substance as well as the identity of the substance
Which of the following compounds contains a polyatomic ion?
NaOH
Which statement concerning the relative strength of acids is FALSE?
Strong acids produce strong conjugate bases; weak acids produce weak conjugate bases
Which of the following represent STP (Standard Temperature and Pressure) conditions?
T= 273 K and P= 1 atm
What does it mean if an atom is said to have a high electronegativity?
The atom has a strong attraction for electrons in a chemical bond
Which statement concerning atoms is FALSE?
The mass number of an atom is the sum of the number of protons, neutrons and electrons it contains
HCl is a strong electrolyte. A bottle of HCl contains the label 0.015 M HCl(aq). Which statement concerning this HCl solution is FALSE?
The pH of the solution is 1.5.
Which of the following statements correctly describes Boyle's Law?
The pressure of a gas is inversely proportional to the volume of the gas, if the temperature and amount remain constant
Aluminum metal and oxygen gas are produced when aluminum oxide is heated at high temperature. Which statement concerning this chemical change is true?
The reaction is a decomposition reaction.
What is always a characteristic of a solution that contains a buffer?
The solution resists large changes in pH when small amounts of acids or bases are added
Which of the following correctly describes what happens when red blood cells are placed in a hypertonic solution?
There will be net movement of water out of the red blood cells and the cells will shrink and collapse
When hydrogen (H2) and chlorine (Cl2) gases are mixed, hydrogen chloride (HCl) is produced. Hydrogen chloride is classified as what type of matter?
a compound
Sarin is a nerve gas that was previously used as a chemical weapon. Considering the physical properties of sarin shown in the table, which statement about sarin is FALSE?
a sample of sarin at 100 degrees celsius exists as a gas
Which of the following statements concerning acids and bases is FALSE?
addition of a base to water increases the hydronium ion concentration of the solution
When a neutral atom gains one or more electrons, what type of particle is formed?
an anion
What is a hypothesis?
an attempt to explain an observation, or a series of observations
Which phrase best describes a metastable isotope?
an isotope that decays by emitting only a gamma ray
What is Rutherford's important contribution to our knowledge of atomic structure?
atoms contain. a small, dense, positively charged nucleus, surrounded largely by empty space
What type of radiation is negatively charged?
beta particle
Which type of radiation is negatively charged?
beta particle
What is the name given to the energy that is responsible for holding the protons and neutrons together in the nucleus?
binding energy
In what region on the periodic table are elements with the lowest electronegativity values found?
bottom left corner
Which of the following is NOT a type of mixture?
compound
What is the three-dimensional arrangement of positive and negative ions in an ionic solid called?
crystal lattice
What are the three primary particles found in an atom?
electron, neutron, and proton
Which type of radiation has the greatest penetrating power?
gamma ray
Which of the following terms is most appropriate when classifying an apple?
heterogeneous mixture
What term is used to describe a solution of lower osmolarity compared to one with a higher osmolarity?
hypotonic
What are the two principal classes of bonding called?
ionic bonding and covalent bonding
What is the name of Fe2+ in the Stock system?
iron(II) ion
What term is used to describe atoms of the same element that have different masses?
isotopes
Which combination of atoms is most likely to form an ionic compound if they are allowed to react with each other?
metal and nonmetal
What is the general term for the process in which one or more electrons are transferred from one reactant to another?
oxidation-reduction
Which statement concerning the three states of matter is FALSE?
particles of a liquid have a rigid, ordered arrangement due to the high speeds of the liquid particles
What type of change alters the appearance, but not the composition or identity of the substance undergoing change?
physical
Which of the following terms best describes the sample of matter in the diagram? Note: different colored circles represent atoms of different elements.
pure substance
What product nucleus results from the alpha decay of radium-226?
radon-222
Which is the summary of a large amount of scientific information?
scientific law
What method used by scientists is the systematic approach to the discovery of new information?
scientific method
What type of membrane allows solvent molecules to pass through but does not allow solute molecules to pass through?
semipermeable
Which of the following correctly describes what is meant by the term neutralization?
the reaction between an acid and a base to form a salt and water
A student mixes 4.0 g of KNO3 with 5.0 mL of water at room temperature, and observes that most, but not all, of the KNO3 has dissolved. Which statement concerning this solution is TRUE?
the solubility of KNO3 in water has been exceeded
Which of the following statements correctly describes Charles's Law?
the volume of a gas is directly proportional to the Kelvin temperature of the gas, if the pressure and amount of gas remain constant
One mole of sodium chloride is added to 100 mL of water in beaker A. One mole of glucose, C6H12O6, is added to 100 mL of water in beaker B. How much more will the freezing point of water be lowered in beaker A than in beaker B?
twice as much
Vitamin D is essential for the normal development of teeth and bones. A tablet of Vitamin D is tested for its solubility in water and benzene. The results are shown in the table below. What is the most appropriate interpretation of the solubility results?
vitamin d is likely a non polar substance
What happens when a hypotonic solution is separated from a hypertonic solution by an osmotic membrane?
water molecules move from the hypotonic solution to the hypertonic solution
