Chem midterm
Convert 3 days -> seconds
((3 d)/1)(24hr/1d)(60min/1hr)(60s/1min)= 259,200→ 3x10^5 s
Convert 25 m/s to miles/hr given [1609.344 m=1. mi]
(25 m)/s (1mi/1609.344m)(60s/1min)(60min/1hr)= 56 mi/s
Convert 261 g -> kg
(261 g)/1 (kg/1000g)=.261kg
Convert 5.93 cm3 -> m3
(5.93 cm^3)/1 (1000mm/100cm)(1000mm/100cm)(1000mm/100cm)= 5.93x10^3 m^3
Convert 9,474 mm -> cm
(9474 mm)/1 (100cm/1000mm)=947.4 cm
C to F Calculation
(F - 32) / 1.8
Frequency
(v) The number of waves that pass a point in 1 second
Wavelength
(λ) the distance between the peaks of adjacent waves
Cooling 0.450 kg of water from 80.0 C to 35.0 C
-84700J -20300 cal
Convert 0.73 kL -> L
.73kL/1 (1000L/1kL)=730 L or 7.3x10^2 L
A 15.2 g sample of metal that absorbs 231 J when its temperature rises from 84.5C to 125.3 C
0.372 J/g C
1000 Joules = ________ KJ
1
1000 cal = _____ kcal
1
s # of orbitals
1
1 L = ____ qt
1.057
Number of moles of NH3 (ammonia) in 7.52 x 10^23 molecules of NH3
1.25 mol of NH3
Number of Zn atoms in 0.250 mol of Zn
1.51 x 10^23 atoms of Zn
1m = ____ cm
100
In an element, 69.15% of the atoms have an atomic mass of 62.930 amu. If there is only one other isotope of the element in the sample and its atomic mass is 64.928 amu, what is the atomic mass of the element? Use the periodic table for the symbol / name of the element
100 - 69.15 = 30.85 62.930 amu X 69.15/100 + 64.928 X 30.85/100 = 63.55 amu 63.55 amu = Copper (Cu)
1L = ____ ml
1000
1kg = ____ g
1000
4f sublevel = # of electrons
14
Find the Molar Mass of (NH4)3 PO4
149.10 g/mol
Silicon electron configuration
1s2 2s2 2p6 3s2 3p2
2s Orbital = # of electrons
2
4p orbital = # of electrons
2
orbital has maximum number of electrons
2
0.002 m in Scientific Notation
2.0 x 10^-3
1 kg = ____ lbs
2.205
240000 cm in Scientific Notation
2.4 x 10^5 cm
1 in = ____ cm
2.54
Calculate the number of particles given molecules of C3H8 in 20.8g of C3H8
20.8g C3H8 x (1 mol / 12 x 3 + 1 x 8 g C3H8 ) x (6.022 x 10^23 C3H8 / 1 mol) = 20.8g C3H8 x (1 mol / 44 g C3H8 ) x (6.022 x 10^23 C3H8 / 1 mol) = 0.47 mol x (6.022 x 10^23 C3H8 / 1 mol) = 2.83 x 10^23 C3H8 ions
p # of orbitals
3
Speed of Light
3.00 x 10^8 m/s = Wavelength(λ) x Frequency(v)
Calculate the percent composition by mass for each C3H6O
36.03 g C/ (36.03 + 6 + 16) g C3H6O x 100% = 12.01 g C/ 58.03 g C3H6O x 100% = C 62.08% 6 g H/ (36.03 + 6 + 16) g C3H6O x 100% = 6 g H/ 58.03 g C3H6O x 100% = H 10.3 % 16 g O/ (36.03 + 6 + 16) g C3H6O x 100% = 16 g O/ 58.03 g C3H6O x 100% = O 27.57 %
1 cal = _____ J
4.184
Atomic Number of Ag
47
What Group / Period Silicon, Si
4A(14) Group 3 Period
d # of orbitals
5
Calculate 58000 cal to kcal
58 kcal
3p Sublevel = # of electrons
6
Formula for Vitamin C is C6H8O6 How many moles of Oxygen are in 1.5 mol of Vitamin C
6 x 1.5 = 9.0 mol (2SF) mol of Oxygen
Calculate 2.8 kJ to cal
670 cal
f # of orbitals
7
Number of Electrons in Oxygen
8
chemical change
A change in which an original substance is converted into a new substance with new properties.
Group
A column on the periodic table
Period
A horizontal row of elements in the periodic table
Element
A pure substance made of only one kind of atom
Chemistry
A science that studies the composition of substances and the way they interact with other substances
Compound
A substance made up of atoms of two or more different elements joined by chemical bonds
Al
Aluminum
Matter
Anything that has mass and takes up space
Calculate the number of moles 38.7 g of CaBr2
Atomic Mass 40 + (79.9 x 2) = 199.8g 38.7 g x ( 1 mol /199.8 g CaBr2) = 0.194 mol of CaBr2
Find the Molar Mass of C13H18O2
Atomic Mass of C13 = 12.01 amu Atomic Mass of H18 = 1.01 amu Atomic Mass of O2 = 16 amu 13 mol C * 12.01 g C/ 1 mol C = 156.13 g of C 18 mol H* 1.01 g H/ 1 mol H= 18.18 g of H 2 mol O* 16 g O/ 1 mol O = 32 g of O 156.13 + 18.18 + 32= 206.31 206.31 g/mol
Isotopes
Atoms with the same number of protons but different numbers of neutrons
Gold
Au
Ba
Barium
Be
Beryllium
Br
Bromine
Carbon
C
Calcium
Ca
Cr
Chromium
Chlorine
Cl
Pick Halogens K, Cl, He, Fe, Mg, Ne, Li, Cu, and Br
Cl, Br
Compound or Element Potassium iodide
Compound
Compound or Element Carbon Dioxide
Compound
Copper
Cu
Scientific Notation Rules
Decimal must be after first non-zero integer Positive exponent means move decimal right Negative exponent means move decimal left Multiplication/Division: add/subtract exponents Addition/Subtraction: exponents must match before calculating
Compound or Element Gold
Element
Compound or Element Iron
Element
Measured or Exact There are 7 days in a week
Exact (Counted)
Measured or Exact A student has 26 DVDs
Exact (counted)
F to C calculation
F = 1.8*C + 32
Iron
Fe
Pick Transition Elements K, Cl, He, Fe, Mg, Ne, Li, Cu, and Br
Fe, Cu
F
Fluorine
Metric Prefixes
Giga, Mega, Kilo, deci, centi, milli, micro, nano
Nonmetals
Greek Letters
Group / Period / Neither Br, Cl, and F
Group
ionic compond
Have Ionic bonds that exist by transferring electrons (forming cations and anions) Ions form a complex in crystalline lattices (ie can't have a molecule of an ionic compound) Typically Metal & Non-metal bonded together or cations and anions
molecular compound
Have covalent bonds that share pairs of electrons Yes, can have one molecule of a compound Non-metals joined together*
Pick Noble gases K, Cl, He, Fe, Mg, Ne, Li, Cu, and Br
He, Ne
H
Hydrogen
Iodine
I
SI Unit of Energy
Joule (J)
Potassium
K
Calculate the number of grams in 3.18 mol of K2SO4
K 2 * 39.1 = 78.2 S 1 * 32.06 = 32.06 O 4 *16 = 64 174.28 Total Molar Mass 3.18 * 174.28 = 554g
Kelvin to C
K = C + 273
Pick Alkali Metals K, Cl, He, Fe, Mg, Ne, Li, Cu, and Br
K, Li
Kinetic or Potential a jogger running
Kinetic
Li
Lithium
Mass is the amount of __________an object is made of
MATTER
Mg
Magnesium
What Element / Symbol 2A(2) Group 3 Period
Magnesium, Mg
45 G is what type of measurement
Mass
Measured or Exact The potatoes have a mass of 2.5 kg
Measured (use a balance)
Pick Alkaline Earth Metals K, Cl, He, Fe, Mg, Ne, Li, Cu, and Br
Mg
Pure Substance or Mixture Sand and water
Mixture
Pure Substance or Mixture bananas and milk
Mixture
A compound that is 75.7% by mass tin (Sn) and 24.3% by mass fluorine (F)
Molar Mass of Sn = 118.69 g Molar Mass of F = 18.998 g Assume we have a 100 g sample then we would have 75.7 g of Sn and 24.3 g of F 75.7 g Sn x (1 mol Sn / 118.69 g Sn) = 0.638 mol of Sn 24.3 g F x (1 mol F / 18.998 g F) = 1.28 mol of F Divide by the smaller number 0.638 mol Sn / 0.638 = 1 mol SN 1.28 mol F / 0.638 = 20 mol F (Should be 2)
Nitrogen
N
Determine the Molecular Formula for each compound using the empirical formula and approximate molar mass given NS, 184 g/mol
N 14.01 g S 32.06 g Mass = 46.07 g 184 g / 46.07 g = 4 N4S4
Sodium
Na
Neon
Ne
Group / Period / Neither C, S, and Br
Neither
Atomic Mass of Ag
Number of Neutrons + Number of Protons 62 + 47 = 109
Oxygen
O
Phosphorus
P
Lead
Pb
Group / Period / Neither K, Ca, and Br
Period
Group / Period / Neither Li, C, and O
Period
Kinetic or Potential Chemical Bonds
Potential
Kinetic or Potential logs sitting in a fireplace
Potential
Pure Substance or Mixture Silver
Pure
Pure Substance or Mixture Sulfur
Pure
Sublevel
Regions of space that electrons occupy make up a principal energy level.
Metals
Roman Numerals
Sulfur
S
Volume is the amount of __________occupied by a substance/object
SPACE
Si
Silicon
Ag
Silver
octet rule
States that atoms lose, gain or share electrons in order to acquire a full set of eight valence electrons
215 Degree C is what type of measurement
Temperature
825 K is what type of measurement
Temperature
^T =
Tf - Ti
Energy
The ability to do work
specific heat
The amount of energy required to raise the temperature of 1 gram of a substance by 1 degree C
absolute zero
The lowest temperature, 0 on the Kelvin scale
Calorimetry
The precise measurement of heat flow out of a system for chemical and physical processes
20 over 11 X and 19 over 11 X are Isotopes because
They have the same number of Protons
3.2 x 10^23 Pb atoms
Use Avagado's number (3.2 x 10^23 atoms) / (6.022 x 10^23 atoms) = 0.53 = 5.3 x 10^-1 mol Atomic Mass of Lead is 207.2g 207.2g/mol x 5.3 x 10^-1 mol = 109.8 g = 110g
Valence Electrons, Group Number, and Symbol in Nitrogen
Valence Electrons=5e- Group Number = 5A(15)
Valence Electrons, Group Number, and Symbol in Oxygen
Valence Electrons=6e- Group Number = 6A(16)
45 L is what type of measurement
Volume
electromagnetic spectrum
Wavelengths radio waves 10^3 microwaves 10^-2 infared waves 10^-5 visible light 10^-6 ultraviolet waves 10^-8 xrays 10^-10 gamma rays 10^-12
Zn
Zinc
Iron Abbreviated Electron Configuration
[Ar]4s2 3d6
Chlorine Abbreviated Electron Configuration
[N3] 3s2 3p5
physical change
a change of matter from one form to another without a change in chemical properties
Orbitals
a region in an atom where there is a high probability of finding electrons
All light travels
at the same speed
p orbital
dumbbell shaped 2 lobes along an axis
valence electrons
electrons in the outermost shell
Nonmetals gain
electrons to become anions
metals loose
electrons to become cations
kinetic energy
energy of motion
molecular formula
formula that gives the actual number of atoms of each element in the compound
E = hv
h = 6.626 x 10^-34 JS
electromagnetic radiation
is all forms of light travels at SAME speed of light 3x10^8 m/s = C
8.3 m is what type of measurement
length
g =
mSH^T
140 G is what type of measurement
mass
Ionic
metal and nonmetal combine No charge, All Positives must have negatives
d and f orbitals
more complex
Avagado's number
number of items in 1 mol that is equal to 6.022x10^23
Atomic Mass
number of protons and neutrons in the nucleus
Sublevel # of Electrons
s = 2 electrons p = 6 electrons d = 10 electrons f = 14 electrons
molecular covalent bond
sharing is Caring
3 states of matter
solid, liquid, gas
s orbital
spherical
potential energy
stored energy
mole
the amount of a substance that contains 6.022x10^23 particles of that substance
molar mass
the mass in grams of an element or compound that is equal numerically to its atomic mass or sum of atomic masses
Atomic Number
the number of protons in an atom
empirical formula
the smallest whole number ratio of the atoms in a formula
The atomic mass of an element is
the weighted average of the masses of an element's isotopes
8.8 s is what type of measurement
time
