#1
Which element is classified as a metalloid?
(1) Cr (2) Sc (3) Cs (4) Si
(4) Si
Determine the oxidation state of copper is the copper compound with the formula, CuO.
What is +2?
What is the total number of electron pairs shared between the carbon atom and one of the oxygen atoms in a carbon dioxide molecule?
What is 2
Which electron configuration represents a potassium atom in an excited state?
(1) 2-7-6 (2) 2-8-8-1 (3) 2-8-5 (4) 2-8-7-2
(4) 2-8-7-2
The gold foil experiment led to the conclusion that each atom in the foil was composed mostly of empty space because most alpha particles directed at the foil did this..
What is went directly through the foil?
Mg(s) 2HCl(aq) → MgCl2(aq) H2
Which type of chemical reaction is represented by the equation?
(1) synthesis
(2) decomposition
(3) single replacement
(4) double replacement
(3) single replacement
Which sample of matter has a crystal structure?
(1) Hg(ℓ) (2) NaCl(s) (3) H2O(ℓ) (4) CH4(g)
(2) NaCl(s)
Which substance can not be broken down by a chemical change?
(1) butanal (2) gold (3) propene (4) water
(2) gold
Which compound is an electrolyte?
(1) H2O (2) H3PO4 (3) C2H6 (4) CH3OH
(2) H3PO4
Which list of elements is arranged in order of increasing electronegativity?
(1) Be, Mg, Ca (3) K, Ca, Sc
(2) F, Cl, Br (4) Li, Na, K
(3) K, Ca, Sc
Which electron configuration represents an excited state for an atom of calcium?
(1) 2-8-7-1 (3) 2-8-7-3
(2) 2-8-7-2 (4) 2-8-8-2
(3) 2-8-7-3
What is the empirical formula for C6H12?
What is CH2?
State the physical property that makes it possible to separate a solution by distillation.
boiling point/boiling temperature
Compare the boiling point of the solution at standard pressure to the boiling point of water at standard pressure.
What is boiling point of a solution is always higher than that of water (and the freezing point is always lower)
2NaHCO3(s) + heat → Na2CO3(s) + H2O(g) + CO2(g)
Determine the total mass of Na2CO3 produced if 3360. kg of NaHCO3 reacts completely to produce 360. kg of H2O and 880. kg of CO2.
What is 2120 kg?
The formula mass of a compound is the
(1) sum of the atomic masses of its atoms
(2) sum of the atomic numbers of its atoms
(3) product of the atomic masses of its atoms
(4) product of the atomic numbers of its atoms
(1) sum of the atomic masses of its atoms
In a laboratory, a student makes a solution by completely dissolving 80.0 grams of KNO3(s) in 100.0 grams of hot water. The resulting solution has a temperature of 60.°C. Classify, in terms of saturation, the type of solution made by the student
What is unsaturated?
Which formula represents a polar molecule?
(1) O2 (3) NH3
(2) CO2 (4) CH4
What is (3) NH3?
Which element is least likely to undergo a chemical reaction?
(1) lithium (3) fluorine
(2) carbon (4) neon
(4) neon
Which radioisotope has the fastest rate of decay?
(1) 14C (3) 53Fe
(2) 37Ca (4) 42K
What is (2) 37Ca?
Compare the amount of heat required to vaporize a 200.-gram sample of H2O(ℓ) at its boiling point to the amount of heat required to melt a 200.-gram sample of H2O(s) at its melting point.
The heat of vaporization is higher, so it takes more heat to vaporize than it does to melt.
What is the molarity of 0.50 liter of an aqueous solution that contains 0.20 mole of NaOH (gram-formula mass = 40. g/mol)?
(1) 0.10 M (3) 2.5 M
(2) 0.20 M (4) 0.40 M
(4) 0.40 M
The three nuclides, U-233, U-235, and U-238, are isotopes of uranium because they have the same number of protons per atom and
(1) the same number of electrons per atom
(2) the same number of neutrons per atom
(3) a different number of electrons per atom
(4) a different number of neutrons per atom
(4) a different number of neutrons per atom
Which statement describes an electrolyte?
(1) An electrolyte conducts an electric current as a solid and dissolves in water.
(2) An electrolyte conducts an electric current as a solid and does not dissolve in water.
(3) When an electrolyte dissolves in water, the resulting solution conducts an electric current.
(4) When an electrolyte dissolves in water, the resulting solution does not conduct an electric current.
(3) When an electrolyte dissolves in water, the resulting solution conducts an electric current.
In how many days will a 12-gram sample of 131I decay, leaving a total of 1.5 grams of the original isotope?
What is 24 days?