EXAM 1

Sig figs/scientific notation/conversions

100

Set up dimensional analysis

# units of you have x _______= #units you want

units you want/units you have

200

12.5849 mg + 2.4 mg=

*correct sig figs!

15.0 mg

300

0.001 or 10^-3 matches which prefix?

Milli

400

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

500

(5.55 x 10^15) (8.88 x 10^18) =

4.93 x 10^34

Periodic table, properties, temperature

100

Which one is a metal? Which one is the most electronegative?

-Nitrogen

-Fluorine

-Argon 

-Strontium

-Phosphorous 

Fluorine

200

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

300

Which one is a chemical change?

Solid->liquid

Tarnish/rust

Melting butter

Dissolving salt in water

Tarnish/rust 

other ones: burning, rotting, and cooking

400

What is 43.8 degrees celsius in kelvin?

316.95 K 

How many sig figs?

500

What is the conversion factor to go from Celsius to Fahrenheit?

celsius temp=Temp Fahrenheit-32/1.8

Atomic Theory, mass percent, subatomic particles

100

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.

200

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%

300

Identify boron and sodium Mass number, Atomic number, proton, neutron, and electron

Boron: 11, 5, 5, 6, 5

Sodium: 24, 11, 11 , 11, 12

400

A compound with 45 protons 44 neutrons and 43 electrons has what charge?

-2

500

235  (top) 92 (bottom)

U

Identify atomic #, Mass #, protons, neutrons, and electrons

92, 235, 92, 143, 92

Ion naming, acids, electron configuration, ionic vs covalent

100

Identify the ionic bond and the covalent one

MgCl2

NaF

MgCl2 is ionic

NaF is covalent

200

Lead (II) chlorite

SF6

S3N2

K2(SO3)

1. Pb2(PO4)4

2. Sodium Hexafluoride

3. Trisulfur Dinitride

4. Potassium Sulfite

300

Write the formula for phosphoric acid

H3PO4

400

Write the electron configuration for chlorine

1s2 2s2 2p6 3s2 3p5

500

Write the electron configuration for phosphorous 

1s2 2s2 2p6 3s2 3p3

Density, Lewis structures, VSPER

100

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 

200

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

300

Draw the lewis structure for carbonate and identify its molecular geometry 

^{Molecular Geometry}

400

Draw the lewis structure and identify both central atom and molecular geometry. Is it polar?

26 valence electrons bc of -3 charge!

polar

central atom: tetrahedral

molecular: trigonal pyramidal

(Be comforting drawing the dipole moments)

500

What is the molecular geometry of CH2F2

Tetrahedral