Chem Exam 2
What is the mass of one mole of carbon atoms?
12.01 g
Determine the number of moles in 50.0 grams of sodium
2.17 g
Determine the number of moles in 3.00 x 10²¹ atoms of calcium.
4.98 x 10⁻³ moles
Avogadro's number
6.02 x 10^23
Convert 6.50g of Copper (Cu) into moles Cu
6.50g / 1 x 1 mol Cu / 63.546g Cu = 0.1023g Cu
The recommended daily allowance of niacin (Vitamin B3) - C6H5NO2 - is 14.0 mg/day for women. Calculate the number of molecules of niacin in 14.0 mg
6.85 x 1019
Based on their positions in the periodic table, which of the following bonds is the most polar?
B - F
What would be the correct formula for a compound comprised of Barium and Sufur?
BaS
Write the chemical formula for bromine pentachloride
BrCl₅
What is the correct formula for Carbon Tetrafluoride?
CF4
What type of bond would occur between Phosphorous and Oxygen?
Covalent
Which of the following bonds is a nonpolar covalent bond?
F - F
Which element has the electron configuration 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p²?
Ge
Which of the following bonds is a polar covalent bond?
H - Cl
The molecule NaBr is:
Ionic
What type of bond would be formed between Potassium and Iodine?
Ionic
Which of the following is an example of an ionic bond?
Na - O. A bond between a metal and non-metal
What would be the correct name of the following compound? RbCl
Rubidium Chloride
What would be the correct name of the following compound? Na2SO4
Sodium Sulfate
Write the chemical formula for tellurium hexaiodide
TeI₆
Electronegativity
ability to attract electrons
What is the correct IUPAC name for AlBr₃?
aluminum bromide
Valence electrons
are the outermost, highest energy electron
Ions
atoms will gain or lose electrons to have 8 valence electrons - form ions
What is the correct IUPAC name for BrCl₃?
bromine trichloride
What is the correct IUPAC name for As₂S₅?
diarsenic pentasulfide
non polar covalent bond
equal sharing of electrons
Anions
gain electrons, become more negative (non-metals) (written with "ide")
Cations
lose electrons, become more positive (metals)
1,2,3,4,5,6
mono, di, tri, tetra, penta, hexa
Mole
one mole of an element = is equal to its amu
Which of the following best describes what happens when an ionic bond forms?
two atoms, one atom which is more electronegative than the other, exchange electrons and the charges hold the atoms together.
Polar covalent bonds
unequal sharing of electrons (dipole movement)
Atoms are most stable:
when they have 8 electrons in their valence shell (exceptions: H & He)
What is the electron configuration for Al?
1s²2s²2p⁶3s²3p¹
