Chemistry 1-3 questions

false

hydrogen bonding is stronger, the larger (more massive) the molecule

true

the two strands of DNA are held together by hydrogen bonding

true

the ideal gas law assumes that intermolecular forces are negligible

false

the ideal gas law fails to yield accurate results at high temperatures

true

the vapor pressure of a liquid depends on the percent of the molecules in the liquid that have enough kinetic energy to escape into the gas phase

false

the stronger the intermolecular forces in a liquid, the higher the liquid’s vapor pressure

false

if a molecule contains polar bonds, then the molecule is necessarily polar

true

the polarity of a molecule will greatly affect its physical properties

true

all intermolecular forces are electrostatic in origin

false

the stronger the intermolecular interactions the lower the boiling point

true

when the liquid phase is less dense than teh solid phase the melting point decreases as the pressure is lowered

true

gases are always the most stable at high temperatures

false

ice will never sublime into water vapor under any conditions

false

an atom in a molecule can never have less than 8 valence electrons

false

the larger the formal charges, the more stable the structure

true

according to valence bond theory, pi bonds are formed fromm the overlap of unhybridized p orbitals

true

the number of hybrid orbitals an atom forms is equal to the number of regions of the electron density an atom has

true

2s orbitals are always higher in energy than 1s orbits, because 2s are farther from the nucleus

true

hydrogen 1s orbitals are higher in energy than carbon 1s orbitals because the carbon 1s orbitals have a stronger attraction to the carbon nucleus

true

typically the larger the bond-order the stronger the bond

false

the bonding electrons in a covalent bond are never equally shared between teh two atoms forming the bond

false

pi bonds have electron density on the internuclear axis

false

according to the valence bond theory, a single bond is typically a pi bond

are attracted to one another, have appreciable molecular volumes, condense if the temperature is lowered enough

a real gas differs from an ideal gas in that the molecule of real gas,…

true

for something to dissolve in something else, the intermolecular interactions of the mixture have to be of comparable strenght to the intermolecular interactions of the pure stuff

false

when you dissolve something in something else, covalent bonds are broken

false

the ligher the object, the shorter the de broglie wavelength

true

the faster the object the shorter the de broglie wavelength

false

solids are typically the most stable phase at higher temperature

false

when a molecule solid is converted into a liquid, covalent bonds are broken

high compressiblity, relatively large distances between molecules, formation of homogenous mixtures regardless of the natures of non-reaction gas components

what are characteristics of gases?

true

the pahse with the lowest density is the most stable at low pressure

false

solids are typically the most stable at high temperature

false

water is unusual in that its liquid phase is less dense than its solid phase

true

water is relatively good at dissolving ionic solids because water molecules are very polar

true

all molecules experience london dispersion

true

non-polar molecules can be made temporarily by interactions with other non-polar molecules

false

VSEPR theory is based on the idea that molecules have structures that maximize the electrostatic attraction between nuclei and electrons.

true

nonbonding pairs of electrons take up more space than bonding electrons

nitrogen

what is the main component of air

true

a sample’s phase can be changed by either changing the temperature or changing the pressure

true

past the critical point (higher temperature and/or higher pressure) liquids and gases can no longer be differentiated

true

photons have no electric charge

false

for electromagnetic radiation, the higher the frequency, the lower the energy

false

hydrogen bonding only occurs when hydrogen is bound to oxygen and flourine

false

hydrogen bonding is responsible for water’s ability to dissolve ionic solids

true

if the bond of a diatomic molecule is non-polar, then the molecule is non-polar

true

Sigma (σ) bonds have electron density on the internuclear axis

false

The oxidation state is the charge an atom would have if all of the bonds in a molecule were purely covalent.

true

Hybrid orbitals are used to form sigma (σ) bonds and contain lone pairs of electrons

true

The number of hybrid orbitals an atom forms is equal to the number of regions of electron density an atom has.

true

Non-polar molecules can be made temporarily polar by interacting with other nonpolar molecules.

false

London dispersion forces are larger, the more spherically shaped the molecule

false

The heavier the object, the longer the de Broglie wavelength.

false

The faster the object, the longer the de Broglie wavelength.

true

Typically the shorter the covalent bond, the stronger the covalent bond

true

The bigger the difference in electronegativity between two atoms that form a bond, the more polar the bond.

false

If a liquid is cold enough, it will have absolutely no vapor pressure.

false

The stronger the intermolecular forces in a liquid, the higher the liquid’s vapor pressure.

true

a sample’s phase can be changed by either changing the temperature of changing the pressure

true

the lines on the phase diagram indicate where tow phases are simultaneously present

true

all gases have the same average kinetic energy at the same temp

true

the lighter of the gas particle, the faster the gas particle assuming all of the other parameters are the same

false

heavier gas particles have higher average kinetic energy assuming that all of the other parameters are the same

true

endothermic= surrounding to system

true

exothermic= system to surrounding

false

enthalpies of formation are always positive

false

hydration enthalpies are always positive

true

VSEPR theory is based on the electrostatic interacition between different regions of electron density around an atom

false

non bonding pairs of electrons take up less space than boning electrons

true

vapor pressure always increases with increasing temperature

false

the stronger the intermolecular forces in a liquid, the higher the liquid’s vapor pressure.

true

gases are mostly made of empty space

true

the polarity of a moelcule will greatly affect its physical properties

false

according to valence bond theory, the number of hybrid orbitals an atom forms is always less than the number of regions of electron density an atom has

false

the n quantum number can have values from 0 to infinity

true

ml quantum number indicates the relative orientation of an orbital

false

hydrogen bonding is stronger, the larger more massive the molecule

true

secondary structures of proteins are due to hydrogen bonding

true

london dispersion are larger, the larger the molecule

true

non polar molecules can be made temporarily polar by interaction with other non-polar molecules

false

the enthalpy of a compound can be determined in absolute terms

true

the gas phase of a compound always has higher enthalpy than its liquid phase

true

bullet never behave as if composed of waves

false

light is composed of particles

true

when the liquid phase is less dense than the solid phase the melting point decreases as the pressure is lowered

true

ice will sublime into water vapor under certain conditions

true

gases are always the most stable phase at high temps

false

for electromagnetic radiation, the shorter the wavelength, the lower the frequency

true

ice melting is an endothermic process

true

ice melting has a positive change in enthalpy

true

s orbitals are spherical

false

all orbitals in an atom have unique set of 4 quantum numbers(n, l, ml, ms)

true

stronger the intermolecular interactions the higher the melting point

false

typically the longer the covalent bond, the stronger the covalent bond

false

the bigger the difference in electronegativity between two atoms that form a bond, the less polar the bond

true

when a molecule has multiple resonance structures, the actual structure is a weighted average of the resonance structures

true

formal charges can be used to tell how stable a lewis electron diagram is