Practice Semester 2 Final
At n=1 the total number of electrons that could be found is
2
The electron notation for aluminum (atomic # 13) is
1s², 2s², 2p⁶, 3s², 3p¹
What is the oxidation number of a pure element
0
Which of these measurements has only non-significant zeros
0.0037 mL
Which of the following lists atomic orbitals in the correct order they are filled according to the Aufbau Principle?
1 s, 2 s, 2 p, 3 s, 3 p, 4 s, 3 d, 4 p, 5 s
Which coefficients correctly balance the formula equation CaO + H₂O → Ca(OH)₂
1,1,1
The pH of a solution is 10.00 what is its OH concentration
1.0 x 10 ⁻⁴ M
Which expression represents the concentration of H₂O⁺ ions in solution
10 ^⁻¹⁴ / [OH⁻]
What is the pH of a 0.027 M KOH solution
12.43
For the reaction represented by the equation 2Na + 2H₂O → 2NaOH + H₂, how many grams of sodium hydroxide are produced from 3.0 mol of sodium with an excess of water?
120 g
Chlorine has an atomic number of 17 and mass number 35, it has
17 protons, 17 electrons, and 18 neutrons
For the reaction represented by the equation Cl₂ + 2KBr → 2KCl + Br₂, how many grams of potassium chloride can be produced from 300. g each of chlorine and potassium bromide?
188g
Which equation is not balanced?
2 H₂ + O₂ → H₂O
The molar mass of NO₂ is 46.01 g/mol. How many moles of NO₂ are present in 114.95 g?
2.498 mol
The reaction represented by the equation C + 2H₂ → CH₄, how many moles of hydrogen are required to produce 10 mol of methane, CH₄?
20 mol
Which of the following is the right side of the equation for dissolving K₂S(s)?
2K⁺(aq) + S²⁻(aq)
The number of significant figures in the measurement 0.000305 kg is
3
When 5.7 m is divided by 2 s, the quotient that is correctly reported is
3 m/s
How many atoms of fluorine are present in a molecule of carbon tetraclouride, CF₄
4
If [H₃O⁺]=8.26x10⁻⁵ M what is the pH of the solution?
4.083
What is the percentage composition of CuCl₂
47.27% Copper, 52.73% Chlorine
In the reaction represented by the equation 2Al₂O₃ → 4Al + 3O₂, what is the mole ratio of aluminum to oxygen
4:3
How many moles of ions are produced by the dissociation of 1 mol of Al₂(CO₃)₂?
5 mol
The number of grams equal to 0.5 kg is
500. g
A sample of oxygen occupies 560. mL when the pressure is 800.00 mm Hg. At constant temperature, what volume does the gas occupy when the pressure decrease to 700.00 mm Hg
640 mL
The volume of a gas is 93. mL, when the temperature is 91°C. If the temperature is reduced to 0°C without changing the pressure, what is the new volume of the gas?
70 mL
When a solid produced by a chemical reaction separates from the solution it is called
A precipiate
A compound is
A substance, made of two or more atoms that are chemically bonded, that can be broken down into simpler, stable substances
The elements in Group 1 are also known as the
Alkali metals
Name the compound Al₂S₃
Aluminum Sulfide
A spherical electron cloud surrounding an atomic nucleus would best represent
An s orbital
The most characteristic property of the noble gases is that they
Are largely unreactive
Evidence gathered since Mendeleev's time indicated that a better arrangement than atomic mass for elements in the periodic table is an arrangement by
Atomic gases
The total number of protons and neutrons in the nucleus of an atom is its
Atomic number
Dalton's atomic theory agrees with modern atomic theory except for the statement that
Atoms are not divided in chemical reactions
The number of atoms in a mole of any pure substance is called
Avogadro's number
Acids react with
Bases to produce salts and water
A positive ion is known as a(n)
Cation
Nuclear forces exist because the particles in the nucleus are
Close together
To balance a chemical equation, it may be necessary to adjust the
Coefficents
Which of the following pairs of solutions produces a precipitate when combined?
Cu(NO₃)₂ and K₂CO₃
A compound's empirical formula is CH. If the formula mass is 29 amu, what is the molecular formula?
C₂H₂
The molecular formula for vitamin C is C₆H₈O₆. What is the empirical formula
C₃H₄O₃
In what kind of reaction does a single compound produce two or more simpler substances?
Decomposition reaction
In a row in the periodic table, as the atomic number increases, the atomic radius generally
Decreases
The equation AX + BY → AY + BX is the general equation for a
Double- Displacement reaction
When an electron is acquired by a neutral atom, the energy change is called
Electron affinity
A measure of the ability of an atom in a chemical compound to attract electrons from another atom in the compound is called
Electron configuration
In metallic bonds, the mobile electrons surrounding the positive ions are called a(n)
Electron sea
An electron for which n=4 more _____ than an electron for which n=2
Energy
For an electron in an atom to change from the ground state to an excited state?
Energy must be absorbed
Which reactant controls the amount of product formed in a chemical reaction?
Excess reactant
A physical change occurs when a
Glue gun melts a glue stick
If electrons in an atom have the lowest possible energies, the atom is in the
Ground state
The vertical columns of the periodic table are called
Groups
The reason the boiling point of water is higher than the boiling point of hydrogen sulfide is partially explained by
Hydrogen bonding
In writing a chemical equation that produces hydrogen gas, the correct representation of hydrogen gas is
H₂
Which of the following is not an oxyacid?
H₂O₂
Which of the following is a diprotic acid?
H₂SO₄
The formula for the hydronium ion (not the hydrogen ion) is
H₃O⁺
Dissolving HCl in water produces
H₃O⁺ and Cl⁻
The greater the electronegativity between two bonded atoms the greater the percentage of ____ in the bond.
Ionic character
A water solution whose pH is 4
Is always acidic
The symbols for units of length in order from largest to smallest are
Km, m, cm, mm
In drawing a Lewis structure, the central atom is generally the
Least electronegative atom
Matter includes all of the following except
Light
Use VESPR theory to predict the shape of the hydrogen chloride molecule, HCl
Linear
If electromagnetic radiation A has a lower frequency that electromagnetic radiation B then compared to B, the wavelength of A is...
Longer
Isotopes are atoms of the same element that have different
Masses
The average atomic mass of an element is the average of the atomic masses of its
Naturally occurring isotopes
Argon, Krypton, and Xenon are
Noble gases
Experiments with cathode rays led to the discovery of the
Nucleus
Most of the volume of an atom is occupied by the
Nucleus
A three dimensional region around a nucleus where an electron may be found
Orbital
The set of orbitals that are dumbbell shaped and directed along the x,y,z axes are called
P orbitals
What is the formula for the compound formed by lead (II) ions and chromate ions?
PbCrO₄
According to Bohr, electrons cannot reside at ____ in the figure below
Point C (Between two orbitals)
If repeated measurements agree closely but differ widely from the accepted value, these measurements are
Precise, but not accurate
What does the constant bombardment of gas molecules against the inside walls of a container produce
Pressure
The reaction represented by the equation Cl₂(g) + 2KBr(aq) + Br₂(l) is a(n)
Single-displacement reaction
Visible light, X-rays, infrared radiation, and radio waves all have the same
Speed
A substance that ionizes nearly completely in aqueous solutions and produces H₃O⁺ is a
Strong acid
The reaction represented by the equation 2Mg(s) + O₂(g) → 2MgO(s) is a
Synthesis reaction
The statement that no two electrons in the same atom can have the same four quantum numbers is
The Pauli Exclusion Principle
If the percentage yield is equal to 100% then
The actual yield is equal to the theoretical yield
Which of the following observations is quantitative?
The liquid boils at 100°C
An atom is
The smallest unit of matter that maintains its chemical identity
Mendeleev predicted that the spaces in his periodic table represented
Undiscovered elements
The electrons available to be lost, gained, or shared when atoms form compounds are called
Valence electrons
Under ordinary conditions of temperature and pressure, the particles in a gas are,
Very far away from one another
Pure water contains?
Water molecules, hydronium ions, and hydroxide ions
Name the compound Zn₃(PO₄)₂
Zinc Phosphate
What is the formula for Zinc Fluoride
ZnF₂
If a mixture in composition, it is said to be
homogeneous
The units of molar mass are
g/mol
If two covalently bonded atoms are identical, the bond is
nonploar covalent
The letter designations for the first four sublevels with the maximum number of electrons that can be accommodated in each sublevel are
s:2, p:6, d:10, and f:14
The two most important properties of all matter are
taking up space and having mass