Chem Exam 1
Which of the following numbers contains three significant figures?
0.00230
The number 8.72 × 10⁻³ when taken out of scientific notation would be
0.00872
The number 6.11 × 10⁻² when taken out of scientific notation would be
0.0611
Perform this mathematical operation and express the answer to the correct number of significant figures: 0.085631 × 1.32
0.113
Which of the following represents an exact quantity?
1 inch is 2.54 centimeters
Which of the following temperatures is the coldest?
100K
How many carbon atoms are in 19 molecules of benzene, C₆H₆?
114
A large stone weighs 53.0 kg How many pounds does it weigh?
117 pounds
How many hydrogen atoms are in 27 molecules of diborane, B₂H₆?
162
3.42 + 45.96/0.21 =
220
How many significant figures does the number 67,200 have?
3
The number 4040 has ___ significant figures.
3
The number 64800 has ___ significant figures.
3
How many significant figures does the number 1.006 × 10⁷ have?
4
How many significant figures would this calculation have if it were completed: (9.04 - 8.23 + 21.954 + 81.0) × 3.1416
4
The number 6.040 has ___ significant figures.
4
How many significant figures does the number 0.054901 have?
5
How many significant figures does the number 23.070 have?
5
What is the correct IUPAC name for CoCl₂ ?
Cobalt(II)chloride
Write the chemical formula for copper(II) perchlorate hexahydrate
Cu(CIO4)2 time 6H2O
A molecule has an empirical formula of CH, and its molar mass is known to be 26 g/mol. What is its molecular formula?
C₂H₂
Determine the correct formula for iron(III) perchlorate.
Fe(ClO₄)₃
Ionic bond
Formed when one or more electrons are transferred from one atom to another
Write the chemical formula for dinitrogen tetroxide
N2O4
Classify the following compounds as ionic or covalent: BaO, Fe₂O₃, ZnO.
all three ionic
What is the correct IUPAC name for AlBr₃?
aluminum bromide
The symbol Cr represents the element _____
chromium
What is the name of the SI unit for length?
meter
Which of the following is a step that is NOT in the scientific method?
modifying laws
Carbon dioxide is a _____ compound composed two types of _____ atoms.
molecular; nonmetal
Rutherford's gold foil experiment determined that
most of the space in an atom is empty except for a concentrated area called the nucleus.
What is the correct IUPAC name for HNO₂(aq)?
nitrous acid
Neutral atoms of all isotopes of a given element have the same
number of electrons
Which of the following is the first step in the scientific method?
observation
The atomic mass of germanium (Ge) on the periodic table is 72.630 amu. Which of the following best explains why the atomic mass is a fraction between 72 and 73?
presence of different isotopes
The nucleus of an atom contains:
protons and neutrons
A homogeneous mixture is also called a ____________.
solution
Ignoring the sign, which has a greater magnitude of charge?
they have equal charges
What does the mass number of an atom represent?
total number of protons and neutrons in the atom
Which of the following numbers contains four significant figures?
3.101
The number 3780000 written in scientific notation would be
3.78 × 10⁶
How many significant figures does the number 48.050 have?
5
Express the number 554,780,000,040 in scientific notation to three significant figures.
5.55 × 10¹¹
Which of the following numbers contains five significant figures?
50.260
The number 0.00000620 written in scientific notation would be
6.20 × 10⁻⁶
The number 0.000741 written in scientific notation would be
7.41 × 10⁻⁴
covalent bond
A chemical bond that involves sharing a pair of electrons between atoms in a molecule
Which of the following does NOT describe the element bromine (Br)?
A metalloid, Bromine (Br) is in group 7A (17) making it a halogen. This also means it is a main group element as well as a nonmetal.
Which of the following best defines a scientific theory?
A model used to explain how or why a phenomenon occurs.
Which of the following best defines a scientific law?
A unifying concept; often a mathematical description of the way in which a natural phenomenon occurs.
Which of the following is a covalent compound? A) H₂O₂ B) Na₂S C) CuCl₂ D) CaO
A) H2O2
How do you convert a Celsius temperature to Kelvin?
Add 273.15
If you go mini-golfing, in which of these scenarios are you precise but not accurate?
All of your shots are off, but they all go to the same place.
The element symbol for arsenic is _____
As
Write the chemical formula for diarsenic trioxide
As2O3
What is the correct formula for barium phosphate?
Ba₃(PO₄)₂
Which of the following is an alkaline earth metal?
Beryllium, The alkaline earth metals are found in Group 2 and include Be, Mg, Ca, Sr, Ba, and Ra.
Polystyrene is made up of a series of styrene (C₈H₈) monomer units. What is the empirical formula for styrene?
CH
Which of the following is a covalent compound? A) RbCl B) CO C) MgS D) TiO
CO
Write the chemical formula for calcium chloride
CaCl2
What is the correct formula for calcium oxide?
CaO
Dalton's atomic theory contains the following hypotheses:
Elements are composed of atoms. ∙∙ Compounds are composed of atoms of more than one element. ∙∙ A chemical reaction involves the rearrangement of atoms. ∙∙ All atoms of a given element are identical. ∙∙ Atoms are indestructible.
Write the chemical formula for the hydrogen phosphate ion
HPO4^-2
Classify the following compounds as ionic or covalent: KCl, CrCl₃, Cl₂O
Ionic, ionic, covalent.
What is the formula of a compound containing K⁺ and O²⁻ ions?
K₂O
How do you convert a Celsius temperature to Fahrenheit?
Multiply by 9/5 and then add 32
Write the chemical formula for ammonium hydroxide
NH4OH
Write the chemical formula for the ammonium ion
NH^4+
The element symbol for nickel is _____
Ni
Which scientist determined the charge of the electron?
Robert Millikan
What is the empirical formula of a molecule containing four sulfur atoms and four fluorine atoms?
SF
Of the following compounds, which contains a metalloid?
SiF4
What element has the symbol Ag?
Silver
What is the correct IUPAC name for AgI?
Silver Iodide
Which of the following is a transition metal?
Silver, Transition metals are found in the d-block of the periodic table.
How do you convert a Kelvin temperature to Celsius?
Subtract 273.15
How do you convert a Fahrenheit temperature to Celsius?
Subtract by 32, then multiply by 5/9
When methane is completely combusted in oxygen forming carbon dioxide and water, how does the mass of the reactant gases compare to the products?
The masses of the reactants and products are equal.
Which is true about one formula unit of CaBr₂?
There is 1 positive Ca ion and 2 negative Br ions.
What is the correct IUPAC name for Al(NO₂)₃?
aluminum nitrate
What is the correct IUPAC name for AlPO₄?
aluminum phosphate
What is the correct IUPAC name for BrCl₃?
bromine trichloride
What is the correct IUPAC name for CrBr₃?
chromium(III) bromide
Density is defined as mass _____________ volume.
divided by
The net charge on an atom of a given element changes as ______ are added or removed.
electrons
What element has the symbol Ge?
germanium
Columns on the periodic table are known as
groups
A human is an example of a(n)
heterogeneous mixture
Italian dressing contains olive oil and vinegar, which will separate out from each other if left to sit. This makes the dressing a
heterogeneous mixture
Grape juice is an example of a(n)
homogeneous mixture
Which of the following terms describes what a doctor forms when treating patients prior to ordering medical tests?
hypothesis
Which of the following lists metric prefixes in order from largest to smallest?
kilo-, deci-, centi-, milli-
