Earlier Chapters
A 2.5g pill contains 4% of the active ingredient BY MASS. What mass IN KG of active ingredient is present in one bottle of 100 pills?
.04 * 2.5 = .1g AI per pill
100 pills ( .01g/pill ) * ( 1kg/100g ) = 0.01kg
The empirical formula is CH. The molar mass is 104.14 g/mol. What is the molecular formula?
C8H8
Identify the atoms based on atomic number, and give the number of protons and electrons:
1. 15 Charge = +2
2. 53 Charge = -1
3. 19 Charge = 0
1. P, 13 e-
2. I, 54 e-
3. K, 19 e-
34 g chromium (III) oxide reacts with 12.1g of aluminum to produce chromium and aluminum oxide. If 23.3g of chromium is produced, what mass of aluminum oxide is produced?
Mass of R = Mass of P
22.8g
Arrange these atoms in order of decreasing size
O2-, O-, O
O2- > O- > O
What is the wavelength when an electron goes from n=6 to n=2?
4.104 * 10^-7m
Is the bonding in these molecules polar, nonpolar, or ionic?
1. K3P
2. SO2
3. CH4
1. ionic
2. polar
2. nonpolar
Assign oxidation states for these compounds:
1. MgO2
2. Ag
3. CuCl2
1. Mg = +4, O = -2
2. 0
3. Cu = +2, Cl = -1
Draw the Lewis Structure: polar or nonpolar? Electron geometry?
Element X forms XCl2 and XCl4. Adding 10g XCl2 with excess Cl forms 12.55g XCl4. Calculate the atomic mass of X and ID it.
207.14 g/mol -> Pb