Mod. 13
What's the difference between a heterogeneous and homogeneous mixture?
Homogeneous means it's evenly spread while heterogeneous is unevenly spread.
What is the Law of Conservation of Energy?
Energy can neither be created nor destroyed, only changed.
What are the three rules for collision theory?
Only some collisions will cause a reaction to occur, reactants must collide in the correct orientation, reactants must collide with enough energy to form an activated complex
Chemistry definition of equilibrium?
both reactants and products are present in concentrations in which there are no more changes as time goes on.
Which property turns the litmus paper red?
Acids turn litmus paper red.
What is the equation for finding molarity?
M=mol/ L
What is the difference between an exothermic and endothermic reaction?
Exothermic is when energy is released and endothermic is when energy is absorbed.
Inhibitor
a substance that slows down reaction rates
What do the brackets represent in equilibrium expressions?
concentrations (moles/liters or moles)
What kind of solutions are considered neither acidic nor basic?
A neutral solution is considered neither acidic nor basic.
If temperature increases how will the solute dissolve?
It will dissolve faster.
What is the equation for finding energy/heat?
q=m x c x deltaT
What are the three steps of a reaction mechanism?
elementary steps
What 2 substances do you NOT include in an expression?
solids and liquids
Which property produces OH, and is it a donor or acceptor?
Bases produce more OH ions, and they are acceptors.
A solution contains 3 moles of NaCl dissolved in 1.5 L of water. What is the molarity of the solution?
2 M
A 50 g sample of water is heated from 20°C to 30°C. If the specific heat of water is 4.18 J/g°C, how much heat was absorbed?
q=m x c x deltaT q=50×4.18×10=2090
Why do some particle collisions fail to produce a reaction?
The particles may not collide with enough energy or in the correct orientation.
What does a large equilibrium constant (K) tell you about a reaction?
Products are favored at equilibrium.
What is self-ionization?
Self-ionization is when a substance reacts with itself to form ions.
Compare a saturated solution and an unsaturated solution.
A saturated solution cannot dissolve more solute, while an unsaturated solution can still dissolve more.
A reaction absorbs 500 J of heat from the surroundings. Is it exothermic or endothermic? Explain.
Endothermic, because the reaction absorbs energy.
Explain how concentration affects reaction rate using collision theory.
Higher concentration means more particles are present, causing more frequent successful collisions.
Why does changing concentration disturb equilibrium?
The system tries to counteract the change and restore balance.
the concentration of hydrogen ions [H^+] in a solution is 1.0 times 10^(-5)M, what is the pH of the solution? Is it acidic, basic, or neutral?
The pH is 5, so the solution is acidic (because it is less than 7).