Final Exam Practice Flashcards
Gain a better understanding of General Chemistry concepts
The basic unit for mass in the metric system is
the gram
Which units are less than a gram?
a milligram and a centigram
The meaning of the prefix milli is
1/1000
What is the length 485 cm in kilometers?
4.85*10^-3 km
How many significant digits are allowed in the answer to the following calculation?
(3736.4 mi)/(55.0 hr) = 67.934545 mi/hr
3 sig. digits
A person who weighs 100 pounds has a mass of about
1 kg = 2.20 lbs
45 kg
A length of 25 cm is about
10 inches
Which of the following relations is not correct?
a. 12 inches = 1 foot
b. 1 inch = 1/12 foot
c. 60 seconds = 1 minute
d. 1 hour = 60 minutes
e. all of these are correct
e. all of these are correct
A gallon is equal to 3.785 liters. How many gallons are in 245 liters?
64.7 gal
The symbol for the element silver is
Ag
Neutral atoms
a. are highly charged
b. have the same number of electrons and protons
c. have more protons than electrons
d. are more dense on the outside than on the inside
e. all of these
b. have the same number of electrons and protons
In terms of mass
a. electrons are much less massive than protons
b. electrons are much less massive than neutrons
c. protons and neutrons have similar masses
d. all of these
e. none of these
d. all of these
The atomic number of an element is equal to the
- number of protons in the nucleus of an atom
- number of electrons in a neutral atom of the element
- sum of the protons and neutrons
- sum of the protons and electrons
1 and 2
The nucleon number of an atom is
the number of electrons
The atomic weight of an element is
- the average number of protons
- the average number of protons plus neutrons
- the average number of protons, neutrons and electrons
- the average mass of an atom considering the contributions of all the natural isotopes
2
An atom with 50 protons, 50 electrons and 66 neutrons has a nucleon number equal to
116
Isotopes of an element have an equal number of
protons, different number of neutrons
A column in the periodic table is called a
group or family
The part of the Periodic Table with most of the elemental gases is
the upper right portion
A row in the periodic table is called a
period
Elements that are shiny, malleable and good conductors are
metals
Those elements that are brittle solids or gases and nonconductors are
nonmetal
The periodic table was first established by
Dmitri Mendeleev in 1869
An atom with atomic number 17, and nucleon number 37 has
- 37 protons, 17 neutrons
- 17 protons, 20 neutrons
- 37 electrons, 17 neutrons
- 17 electrons, 20 neutrons
2 and 4
The molecular formula of a particular solid is C8H4O8. Its molecular mass is
228 amu
What is the mass in grams of one propane, C3H8 molecule?
7.32*10^-23
Which of the following compounds contains the largest number of atoms?
a. 1.0 mol of CH3COCl
b. 2.0 mol of H2SO4
c. 3.0 mol of NH3
d. 4.0 mol of K2S
e. 5.0 mol of HBr
2.0 mol of H2SO4
What is the mass of oxygen atoms in 0.395 mol Fe(CO)5?
31.6 g
What is the mass in grams of 0.732 mol of glucose, C6H12O6?
132 g
How many moles of silver are contained in 7.00 kg of silver?
64.9 mol
How many molecules are there in 60.0 g of acetic acid, C2H4O2?
6.02*10^23
How many molecules are there in 2.47 mg of mannose, C6H12O6, which if a sweet-tasting sugar that has a bitter aftertaste?
8.26*10^18
The total number of oxygen atoms in 2.60 g of CaCo3 (MM = 100.0 g/mol) is
4.70*10^22
What is the percentage by mass of sulfur in copper (I) sulfide, Cu2S?
20.1%
Analysis of a compound showed that it contained 14.4% hydrogen atoms and 85.6% carbon atoms by mass. What is its empirical formula?
CH2
How do you find the empirical formula?
Percent to mass
Mass to mole
Divide by small
Multiply til’ whole
Of the following the only empirical formula is
a. C2H8
b. C5H14
c. C6H12
d. H2O2
e. O3
C5H14
A 0.0111-mol sample of urea, NH2CONH2 contains
5.35*10^22 atoms
What is Avogadro’s number?
the number of atoms or molecules in one mole of a substance, equal to 6.023 × 10^23
How many molecules are there in 62.0 g of ethylene glycol, HO(CH2)2OH?
6.02*10^23