Signs of a Reaction; Exo- & Endo-
When a reaction gives off heat, it is....
Exothermic
What type of reaction is this?
2H₂ + O₂ → 2H₂O
Synthesis
_ Ag2O --> __ Ag + __ O2
2Ag2O --> 4Ag + O2
A(n) ________________ speeds up a reaction without being a part of it, kind of like a matchmaker.
Catalyst/enzyme
What does the arrow in a chemical equation mean?
Yields/produces
When a reaction sucks in heat, it is....
Endothermic
What type of reaction is this?
4Al + 3O₂ → 2Al₂O₃
Synthesis
__P + __ O2 --> __ P2O5
4P + 5O2 --> 2P2O5
Would decreasing the amount of reactant speed up or slow down the reaction?
Slow down
Are the reactants on the left or right side?
Left
What happens in a chemical reaction?
New atoms are formed
What type of reaction is this?
2KCl + H2 --> 2HCl + 2K
Single replacement
__HgO + __Cl2 → __HgCl + __O2
2HgO + Cl2 → 2HgCl + O2
Would decreasing the size of the container in which the reaction is taking place speed up or slow down the reaction?
Speed up
What does the symbol KOH (aq) mean?
Potassium Hydroxide (aqueous)
You mix a mysterious clear liquid into water. The color of the water changed from clear to red and the the final product was really bubbly. Did a reaction occur?
Yes; you didn't dye the water so there was an unexpected color change. Also, a gas formed and made bubbles.
What type of reaction is this?
CH2O + O2 --> H2O + CO2
__H2 + __N2 → __NH3
3H2 + N2 → 2NH3
A(n) ____________________ slows down a reaction without being a part of the reaction
Inhibitor
What does the symbol NaCl (s) mean?
Sodium Chloride (solid)
You mix red food coloring into sparkling seltzer water. The color of the water changed from clear to red and the the final product was really bubbly. Did a reaction occur?
No; you dyed the water red and it was already bubbly because it comes that way! No new gas was produced.
What type of reaction is this?
HCl + NaOH --> NaCl + H2O
Double replacement
__C2H6 + __O2 → __CO2 + __H2O
2C2H6 + 7O2 → 4CO2 + 6H2O
Would decreasing the amount of product speed up or slow down the reaction?
Slow down!!
What do 2 opposite arrows sitting one on top of the other mean? (Ms. Lerman will draw a pic)
Equilibrium; the reaction can go forwards or backwards
What are the big numbers in a chemical equation?
Coefficients
What are the two major parts of a chemical equation? (hint: separated by an arrow)
Reactants and products
Determine the parts of this chemical equation:
2C2H6 + O2 → 4CO2 + 6H2O
Coefficients: 2C , 4C and 6H
Elements: Carbon, Hydrogen and Oxygen (C, H and O)
Subscripts: C2, H6, O2, O2, and H2
What is the purpose of a coefficient?
Determine the amount of molecules there is and balance a chemical equation
What is the purpose of the subscript?
Determine the amount of atoms in a molecule