Unit 1: Atoms and Trends
What is the total number of s-orbital electrons in a ground-state sulfur (S) atom?
Six (1s2, 2s2,3s2)
What is the ideal bond angle in a molecule with trigonal planar electron geometry?
120o
The type of intermolecular force that is responsible for Br2 being a liquid at room temperature while Cl2 is a gas.
London Dispersion Forces (LDF)
Name the spectator ions in the reaction between NaOH(aq) and FeCl3(aq).
Na+ and Cl-
The lab technique used to determine the concentration of a solution by reacting it with a solution of known concentration.
Titration
Explain why the second ionization energy of Na is dramatically higher than its first.
Removing the second electron requires breaking into a full, stable noble gas core
Identify a common non-metal element that often forms molecules with an expanded octet.
Phosphorus or Sulfur (elements in Period 3 or below)
Calculate the volume of 0.50 mol of He gas at 273 K and 1.0 atm in Liters.
11.2 Liters
For the reaction 2A + 3B -> C, if you start with equal moles of A and B, which reactant is the limiting reactant?
Reactant B
The property of a liquid that results from the inward force that minimizes the surface area of the liquid.
Surface Tension
The single element whose mass spectrum will show two distinct peaks of approximately equal height.
Bromine (Br-79 and Br-81)
A metallic bond can be described as a lattice of positive ions surrounded by this.
Sea of mobile electrons
Explain why boiling point generally increases as the strength of the intermolecular forces increases.
More energy (heat) is required to overcome the attractive forces and separate the molecules
The compound that is reduced in the reaction: Zn + CuCl2 --> ZnCl2 + Cu.
CuCl2
According to Beer's Law, if the concentration of a solution is doubled, what happens to the measured absorbance?
It doubles
Which ion, F- or Na+, has the smaller ionic radius, and why?
Na+, because it has the same number of electrons (isoelectronic) but more protons (higher Zeff)
Explain why CO2 is nonpolar while COS (Carbonyl Sulfide) is polar.
CO2 is symmetrical with equal opposing bond moments, but S and O have different electronegativities, making COS asymmetrical.
This gas property is a measure of how quickly gas particles pass through a tiny hole, and it is inversely proportional to the square root of molar mass.
Rate of effusion
If a 10.0g sample of a compound containing only C and H yields 30.0 g of CO2 in combustion analysis, what mass of C was in the original sample?
In Ksp calculation, what is the initial concentration of the dissolved salt?
Zero
The term for the decrease in attractive force between the nucleus and outer electrons due to inner electrons.
Shielding
Which solid (KCl or CaO) has a higher melting point, and why?
CaO, because it has higher lattice energy due to the 2+/2- charges (greater Coulombic force)?
In a phase diagram, what term describes the point where the solid, liquid, and gas phases coexist in equilibrium?
Triple Point
Given a reaction with 90% yield, if the theoretical yield is 20.0g, calculate the actual yield.
18.0 grams
Describe the two conditions under which a real gas is most likely to behave non-ideally.
High pressure and low temperature.