Exam 1
Which of the following gives the correct numbers of protons, neutrons, and electrons, respectively, in a neutral atom of Cu with an automic mass of 64?
A) 29 p, 35 n, 28 e⁻
B) 35 p, 29 n, 35 e⁻
C) 29 p, 35 n, 29 e⁻
D) 64 p, 35 n, 29 e⁻
E) 29 p, 64 n, 29 e⁻
C) 29 p, 35 n, 29 e⁻
The reaction of hydrogen gas with iodine to form hydrogen iodide is studied under different conditions:
H2(g)+I2(g)−>2HI(g)
Predict how the rate of the reaction will change in each scenario:
The temperature of the system has increased.
The concentration of hydrogen gas is doubled.
A platinum catalyst is added.
A) increase, decrease, increase
B) decrease, increase, increase
C) decrease, decrease, increase
D) decrease, decrease, decrease
E) increase, increase, increase
E) increase, increase, increase
Which of the following substances will probably be soluble in water, a very polar solvent?
A) Potassium chloride (KCl)
B) Octane (C₈H₁₈)
C) Ethanol (C₂H₅OH)
D) Toluene (C₆H₅CH₃)
A & C
Which of the following is the strongest acid?
A) H3PO4
B) NH4+
C) NaOH
D) H2CO3
E) HCl
E) HCl
To a sample of liquid water, 155 kJ of heat is added to vaporize all the liquid to vapor at 100 °C. What is the mass of the water sample?
A) 68.6 g of water
B) 0.0146 g of water
C) 350. g of water
D) 14.6 g of water
E) 0.0686 g of water
A) 68.6 g of water
The solubility of KNO₃ is 32 g in 100 g of H₂O at 25 °C. If 80 g of KNO₃ are added to 200 g of H₂O, will all of the KNO₃ dissolve?
A) Yes, all will dissolve
B) No, some will remain undissolved
B) No, some will remain undissolved
According to the reaction below, how many grams of solid BaSO4 are formed when 150 mL of 1.80 M aqueous Na2SO4 reacts with excess aqueous BaCl2?
(Note: Molar Mass of BaSO4 = 233.39 g/mol)
BaCl2(aq)+Na2SO4(aq)→BaSO4(s)+2NaCl(aq)
A) 62.9 g
B) 53.0 g
C) 44.5 g
D) 49.9 g
E) 36.0 g
A) 62.9 g
Which of these solutions are basic?
A) a solution with a pH = 2.5
B) a solution with [H3O+] = 1 x 10^-9
C) a solution with pH = 7.0
D) a solution with [OH-] = 2 x 10^-11
E) a solution with a pH = 10
B & E
The prescribed dosage of ibuprofen for an adult with mild pain is 400 mg every 6 hours. If the patient is instructed to continue the medication for a total of 5 days, what is the total mass, in milligrams, of ibuprofen taken?
A) 8,000 mg
B) 4,000 mg
C) 10,000 mg
D) 12,000 mg
A) 8,000 mg
A 25.0 mL sample of an unknown H₂SO₄ solution requires 150 mL of 0.200 M NaOH to completely react with the H₂SO₄. What is the molarity (M) of the unknown H₂SO₄ solution?
H2SO4(aq)+2NaOH(aq)−>Na2SO4(aq)+2H2O(l)
A) 0.200 M
B) 0.300 M
C) 0.600 M
D) 0.800 M
E) 1.200 M
C) 0.600 M
What mass of H₂ is needed to completely react with 0.250 moles of N₂ (g) based on the reaction below?
N2(g)+3H2(g)→2NH3(g)
A) 1.50 g H₂
B) 0.75 g H₂
C) 3.00 g H₂
D) 2.25 g H₂
E) 0.50 g H₂
A) 1.50 g H₂
The H3O+ concentration of a substance is approximately 3.2 x 10^-10 M. What is the pH of the solution?
A) 3.5
B) 7.0
C) 9.5
D) 10.5
C) 9.5