Sig figs/scientific notation/conversions
Set up dimensional analysis
# units of you have x _______= #units you want
units you want/units you have
Which one is a metal? Which one is the most electronegative?
-Nitrogen
-Fluorine
-Argon
-Strontium
-Phosphorous
Fluorine
What are the differences between Dalton’s atomic theory and the modern quantum mechanical model of the atom
According to Dalton's atomic theory, atoms are indivisible particles. Modern atomic theory says that atoms are composed of subatomic particles; protons, electrons, and neutrons. Dalton's theory does not explain details about isotopes.
Identify the ionic bond and the covalent one
MgCl2
NaF
MgCl2 is ionic
NaF is covalent
28.5 g of iron shot is added to a graduated cylinder containing 45.50 mL of water. The water level rises to the 49.10 mL mark, From this information, calculate the density of iron.
vol of iron shot = 49.10 mL - 45.50 mL = 3.60 mL
d = 28.5 g / 3.60 mL
d = 7.92 g/mL
12.5849 mg + 2.4 mg=
*correct sig figs!
15.0 mg
Which element would have physical and chemical properties similar to chlorine? Write the name of the element.
A. Ar
B. Br
C. S
D. O
Bromine! Same group aka column so will have similar properties
Analysis of 4.200 g of vitamin C yields 1.720 g of carbon, 0.190 g of hydrogen, and 2.290 g of oxygen. Calculate the mass percentage of each element in the compound
40.95%
4.52%
54.52%
Lead (II) chlorite
SF6
S3N2
K2(SO3)
Pb2(PO4)4
Sodium Hexafluoride
Trisulfur Dinitride
Potassium Sulfite
How many lone pairs are located on the central atom of carbon dioxide also is it polar?
0! all 8 are on surrounding atoms
(4 on the oxygen and 4 on the other oxygen)
yes polar covalent
0.001 or 10^-3 matches which prefix?
Milli
Which one is a chemical change?
Solid->liquid
Tarnish/rust
Melting butter
Dissolving salt in water
Tarnish/rust
other ones: burning, rotting, and cooking
Identify boron and sodium Mass number, Atomic number, proton, neutron, and electron
Boron: 11, 5, 5, 6, 5
Sodium: 24, 11, 11 , 11, 12
Write the formula for phosphoric acid
Draw the lewis structure for carbonate and identify its molecular geometry
Molecular Geometry
How many cg are in 2.49 x 10^3 mg?
249 cg
( 1 g / 1000 mg)(100 cg / 1 g) = 249 cg or 2.49 x 10^2 cg
What is 43.8 degrees celsius in kelvin?
316.95 K
How many sig figs?
A compound with 45 protons 44 neutrons and 43 electrons has what charge?
-2
Write the electron configuration for chlorine
1s2 2s2 2p6 3s2 3p5
Draw the lewis structure and identify both central atom and molecular geometry. Is it polar?
26 valence electrons bc of -3 charge!
polarcentral atom: tetrahedral
molecular: trigonal pyramidal
(Be comforting drawing the dipole moments)
(5.55 x 10^15) (8.88 x 10^18) =
4.93 x 10^34
What is the conversion factor to go from Celsius to Fahrenheit?
celsius temp=Temp Fahrenheit-32/1.8
235 (top) 92 (bottom)
U
Identify atomic #, Mass #, protons, neutrons, and electrons
92, 235, 92, 143, 92
Write the electron configuration for phosphorous
1s2 2s2 2p6 3s2 3p3
What is the molecular geometry of CH2F2
Tetrahedral