Solubility
What is solubility?
The ability of a substance to dissolve in a solvent to form a homogeneous mixture.
What is density?
The mass of a substance divided by its volume, essentially indicating how tightly packed the matter is within a given space.
What is the difference between an ionic and covalent bond?
Answers may vary. Ionic = metal + nonmetal, Covalent = nonmetal + nonmetal (or metalloid)
Ionic - transfer electrons
Covalent - share electrons
What is polarity?
The distribution of electrical charge over the atoms joined by the bonds.
Is HCl polar or nonpolar? (electronegativity values for H is 2.1 and 3.0 for Cl)
The electronegativity difference is 0.9, so HCl is a polar molecule.
In regard to solubility, what does "like dissolves like" mean?
Polar molecules can dissolve in polar solvents and non-polar molecules can dissolve in non-polar solvents.
D = ?
V = 950 mL
m = 95 g
0.10 g/mL
Which of the following contains an ionic bond?
CCl4, Cal2, PO3, or N2
CaI2
Is the H2O molecule polar or nonpolar?
polar (2 lone pairs on central atom = bent)
What is the relationship between vapor pressure and IMFs? Explain why it is a direct or inverse relationship?
Inverse relationship because the stronger the IMFs, the tighter the bond is & the harder it is for the bonds to break in order to turn into a gas (vapor).
Which of the following will dissolve in water H2O and why?
CH4, CO2, O3, or SO2
SO2, because it is polar "like" water H2O.
What is the mass of the ethanol that exactly fills a 200.0-mL container, given that the density of ethanol is 0.789 g/mL?
157.8 g =158 g (sig figs)
Which of the following is a covalent compound/bond?
CaO, NO3, K2S, or Al2O3
NO3
Is CH4 a polar or nonpolar molecule?
nonpolar (no lone pairs on C and surrounded by all the same atom)
Which molecule would have the higher boiling point and why: NH3 or CH4?
NH3 because it is polar and has D-D forces and H-Bonding, while CH4 is nonpolar and only has weaker LDF between its molecules.
Which of the following will dissolve in ethane, C2H6 and why?
H2S, NH3, CO2, or C2H5OH
CO2, because it is non-polar "like" ethane.
What volume of silver metal will have a mass of exactly 2.5 kg, given that the density of silver is 10.5 g/cm3? (Hint: Note the units of mass given and the units of density.)
2500 g
238.1 cm3 = 238 cm3 (sig figs)
Using the periodic table, predict whether the following chlorides are ionic or covalent: KCl, NCl3, ICl, MgCl2, PCl5, and CCl4.
Ionic: KCl, MgCl2
Covalent: NCl3, ICl, PCl5, CCl4
Is SF5- a polar or nonpolar molecule?
polar (lone pair on S)
Which has stronger IMFs and why: Cl2 or Br2?
Br2 because it has more electrons than Cl2 and is therefore more polarizable & it has a greater molar mass. Both molecules are nonpolar and only have LDF, but the more polarizable (bigger) the atom, the stronger the LDF.
Alcohol is a relatively non-polar molecule so can it dissolve an ionic solid? Why or why not?
Since alcohol has very weak forces, it is not strong enough to overcome the very strong ionic electrostatic forces.
A rectangular block of copper metal has a mass of 1896 g. The dimensions of the block are 8.4 cm by 5.5 cm by 4.6 cm. From this data, what is the density of copper? (Hint: Find the volume of the block first.)
212.52 cm3
8.922 g/cm3
For each of the following pairs of ions, write the formula of the compound they will form:
(a) Ca2+, S2−
(b) NH+4, SO2−4 (c) Al3+, Br−
(d) Na+, HPO2−4
(e) Mg2+, PO43-
CaS, (NH4)2CO3, AlBr3, Na2HPO4, Mg3(PO4)2
Is ICl2- a polar or nonpolar molecule?
Nonpolar. All three lone pairs on I would be in the equatorial positions, while the Cl atoms would be axial and 180 degrees from eachother, making a linear shape overall.
You have two sealed jars. One has liquid Br2 and the other has liquid H2O. Which jar would you expect to have more molecules in the gaseous state after 10 minutes and why?
Br2 because it only has LDF (nonpolar molecules). H2O has stronger hydrogen bonding so the molecules will be more likely to remain in the liquid form.