chem regents memorize

What happens in a bright line spectrum?

Electrons fall from excited to ground state, releasing energy.

How do you determine molecular polarity?

SNAP: Symmetrical = Nonpolar, Asymmetrical = Polar.

What determines intermolecular force strength?

Strong = solid/high MP/BP; Weak = gas/low MP/BP.

How do you increase reaction rate?

Increase temp, concentration, or add catalyst (Collision Theory).

Equal volume of gases at same conditions = ?

Equal number of molecules (Avogadro’s Law).

How do you identify an excited state from e⁻ configuration?

Adds up correctly but doesn’t match periodic table ground state.

In electrochemistry, which way do electrons flow?

Anode to cathode.

Heat flows from where to where?

High temperature to low temperature.

Empirical vs molecular formula?

Empirical = reduced; Molecular = unreduced.

How do you count significant figures in 0.010?

2 sig figs (start from first non-zero digit).

Where are acids and bases on Table M?

Acids = left side, Bases = right side.

How do you find the class of organic compounds?

Table R.

101.3 kPa and 298 K are used with which table?

Table I.

Acid vs base definition?

Acid = H⁺ donor; Base = H⁺ acceptor.

How do you find decay mode?

Table N.

What is true at equilibrium?

Rates are equal, concentrations are constant.

What are isomers?

Same molecular formula, different structure.

OIL RIG meaning?

Oxidation Is Loss, Reduction Is Gain.

ANOX, REDCAT meaning?

Anode = Oxidation; Reduction = Cathode.

Ideal gas assumptions?

No forces, negligible volume, random straight-line motion.

What makes isotopes different?

Same protons, different neutrons.

Le Chatelier’s Principle trick?

Increase = shift away; Decrease = stay.

Where is vapor pressure found?

Table H.

Half reaction e⁻ placement rule?

Electrons go on more (+) side.

Element in all organic compounds?

Carbon.

Example of same element with different properties?

Diamond & graphite; O₂ & O₃.

Combined Gas Law formula?

P₁V₁/T₁ = P₂V₂/T₂.

Titration formula?

MₐVₐ = MᵦVᵦ.

% composition formula?

(part / GFM) × 100.

Moles formula?

given mass / GFM.

% error formula?

(measured - accepted) / accepted × 100.

How to do mole-mole questions?

Put X over asked compound, given number over other, cross multiply.

Where are 3 heat formulas found?

Table T; Heat values in Table B.

Direction of natural systems?

Toward lower energy & higher entropy.

State with highest entropy? Lowest?

Gas = highest; Solid = lowest.

Define entropy.

Disorder or randomness.

Average kinetic energy is measured by?

Temperature.

Define electronegativity.

Attraction for electrons.

Define ionization energy.

Energy required to remove an electron.