Chemistry 2

• Covalent bonds result from the __ electrons between two atoms?

  -equal sharing of and unequal sharing of are correct
• A diatomic molecule contains

  I or II only
• identify the diatomic element from the given choices. -chlorine
• Identify the diatomic element from the given choices. -nitrogen
• Which of the following compounds is classified as covalent?

  -HCI
• Which of the following compounds is not classified as covalent?

  -MgCI2
• What is another name for an unshared pair of electrons in a covalent compound?

  -lone pair of electrons or nonbonded electron pair
• How many unbonded electron pairs(lone pair) are in the Lewis structure OCO?

  -4
• Which of the following geometries is incorrectly paired with its corresponding bond angle?

  -trigonal pyramidal 120
• What are the bond angles in tetrahedral geometry?

  -109.5
• Which element is more electronegative than sulfur?

  -Br
• Which bond is the LEAST polar?

  C-C
• What is the correct chemical formula of selenium dioxide?

  -SeO2
• What is the chemical formula for dinitrogen tetroxide?

  -N2O4
• Which of the statements concerning compounds is INCORRECT?

  -covalent compounds are composed of metals and nonmentals
• Which statement concerning chemical bonds is FALSE?

  -a non polar bond is a covalent bond in which electrons are not shared equally between the atoms
• Which statement concerning resonance is FALSE?

  All resonance structures represent accurate representations of the molecules they depict
• What type of bonding cannot be accurately represented using a single Lewis structure?

  -resonance
• In a bond between two chlorine atoms, the electrons are shared __ and the resulting bond is?

  -equally;non polar covalent
• Which ion is the strongest base?

  F-
• Which acid has the strongest conjugate base?

  hydrogen phosphate ion HPO4^2-(Ka=2.2 x 10^-2)
• In the acid base reaction: HCN(aq) - CN-(aq) + HF (aq), where Ka (HCN) = 4.9 x 10^-10 and Ka (HF) = 7.2 x 10^-4, the ?

  Reactants are favored
• Which solution has the highest pH?

  1.0 x 10^-7 M OH-
• What solution has the highest pH?

  1.9 x 10^-8 MH H3O+
• What solution has the lowest pH?

  1.3 x 10^-8 MH OH-
• Maintaining the proper pH in a swimming pool is important to keep the water clean and clear. pH values outside of the optimal range of 7.4 - 7.6 can strip the body of natural oils leaving the skin dry and the hair brittle. A high pH can even cause the water to become cloudy as minerals precipitate out of solution. If the [OH-] of the pool water is 3.4 x 10^-8M, what is the pH and is it within the optimal range?

  pH = 6.54; no, the pH is not within the normal range
• What is the pH of a peach with a [OH-] = 3.2 x 10^-11 M?

  3.51
• What are the products of the acid-base reaction of sodium carbonate with acetic acid?

  CO2(g) + H2O(l) + 2NaCH3COO(aq)
• Which salt forms a solution with a pH < 7 when dissolved in water?

  (NH4)2SO4
• What is the molarity of an HNO3 solution if 24.1 mL of a 0.250 M Ba(OH)2 solution are needed to titrate a 15.0 mL sample of the acid according to the equation below / Ba(OH)2(aq) + 2HNO3(aq)- 2H2O(l) + Ba(NO3)2 (aq)?

  0.803 M HNO3
• While taking inventory of the chemicals in the stockroom, the lab technician finds a bottle of hydrochloric acid whose label has been partially damaged. Because of the damage to the label, the concentration of the aqueous HCI is unreadable. If It takes the lab technician 25.2 mL of a 0.50M NaOH solution to titrate a 21.0 mL volume of the HCL, what is the molar concentration of the HCl?

  0.60M HCl (aq)
• How many millimeters of 0.653 M NaOH are needed to neutralize 25.0 mL of a 1.02 M HBr solution? The neutralization reaction is: NaOH(aq) + HBr(aq) - H2O(l) + NaBr(aq) -39.1 mL NaOH
• What is the pH of a buffer that contains 0.15 M CH3COOH and 0.10 M NaCH3COO (Ka=1.8 x 10^-5)?

  4.57
• An aqueous solution with a low pH is necessary for a certain industrial process. Which of the following solutions would have the lowest pH?

  1.0 M HCl
• The National Football League (NFL) requires that all balls used in regulation play must be inflated to a pressure between 12.5-13.5 psi to ensure that the ball cannot be deformed during gameplay. Identify which ball in the options below can NOT be used during regulation gameplay?

  Ball C: 636 torr
• Some brain injuries cause an increase in intercranial pressure (ICP) which can lead to headaches and in severe cases, neurological damage. The typical range for what is considered normal ICP in adults is 5-15 mmHg. From options below, identify the patient with the ICP that is outside the normal range?

  Patient E: 0.30 psi
• A weather balloon contains 233 L of helium at 22 degrees C and 760. mm Hg. What Is the volume of the balloon when it ascends to an altitude where the temperature is -54 degrees C and 511 mm Hg?

  257 L
• A gas cylinder containing 6.38 mol of neon has a pressure of 491 mm Hg at 295 K. If 3.22 mol of helium is added to this cylinder, at constant temperature and volume, what will be the pressure in the cylinder?

  739 mm Hg
• Which cylinder at STP will contain the greatest mass of gas particles?

  a 5.0 L cylinder of nitrogen
• Consider the balanced reaction: Zn(s) + 2 HCL (aq) - ZnCL2(aq) + H2(g). What volume of H2(g) at STP can be generated when 134 g of zinc reacts?

  45.9 L