Chapter 5: Thermochemistry
True or False: the 1st law of thermodynamics states internal energy of a system changes due to heat flow in or out of the system or work done on or by the system
True
What is described by Hund's rule?
every orbital in a subshell is singly occupied with one electron before any one orbital is doubly occupied, and all electrons in singly occupied orbitals have the same spin
What is represented by the principal quantum number, n?
the shell, or general region for the value of energy for an electron on the orbital
Single bonds = Sigma bonds (σ)
Double bonds = 1 sigma bond + 1 pi bond (𝝅)
Triple bonds = 1 sigma bond + 2 pi bonds
True or False: standard enthalpy of combustion is heat absorbed when one mole of a compound undergoes complete combustion under standard conditions
False, it describes heat released
What does the Aufbau principle state?
The Aufbau principle states that electrons fill lower-energy atomic orbitals before filling higher-energy ones
What is the orbital configuration for N?
1s2 2s2 2p3
A: The number of central atoms
X: The number of sigma bonds between the central atom and outside atoms
E: The number of lone pairs around the central atom
What term is used to describe the capacity to supply heat or do work.
Energy
Which subshell is described by the following quantum numbers?
n = 3, l = 1;
3p
What is represented by the spin quantum number, ms?
What is the molecular geometry of water? (H2O)
sp3 hybridized, tetrahedral
A piece of unknown metal weighs 348 g. When the metal piece absorbs 6.64 kJ of heat, its temperature increases from 22.4 °C to 43.6 °C. Determine the specific heat of this metal
c = 0.900 J/gC
What is described by the Heisenburg uncertainty principle?
rule stating that it is impossible to exactly determine both certain conjugate dynamical properties such as the momentum and the position of a particle at the same time. The uncertainty principle is a consequence of quantum particles exhibiting wave–particle duality
A sodium street light gives off yellow light that has a wavelength of 589 nm (1 nm = 1× 10−9 m). What is the frequency of this light?
c= λv
C is a constant = 2.998 x 108 ms-1
How many sigma and/or pi bonds are in O2
Structure: O=O
1 sigma and 1 pi bond
A flask containing 8.0 × 102 g of water is heated, and the temperature of the water increases from 21 °C to 85 °C. How much heat did the water absorb?
HINT: Specific heat of water = 4.184 J/g oC
2.1 x10^2 kJ
What is the orbital configuration of Al2+
(atomic number = 13)
1s22s22p63s1
What is the orbital configuration of magnesium? (atomic number = 12)
1s2 2s2 2p6 3s2
What is the orbital hybridization of CO2?
sp hybridized