chemical reaction

Question 1

what does (s) (L) (g) (aq) stand for when balancing equation?

Answer 1

s= solid 
L = liquid 
g = gas 
aq = aqueous solution

Question 2

what is a aqueous solution?

Answer 2

where the solvent is water

Question 3

what is a solvent?

Answer 3

a substance that dissolves a solute/ makes a most of the solution

Question 4

what is a solute?

Answer 4

a minor part of the solution/ is dissolved by the the solvent

Question 5

what are the phase changes and their name?

Answer 5

melting - liquids to solid  
vaporization - water to gas
condensation - gas to liquid 
freezing - liquid to solid 
sublimation -  solid to gas 
deposition - gas to solid

Question 6

what is an exothermic reaction?

Answer 6

when heat is released / surroundings hotter after reaction

Question 7

what is an endothermic reaction?

Answer 7

when heat is absorbed / surroundings colder after reaction

Question 8

what are the heat formulas?

Answer 8

ΔH = H(products) – H(reactants)
= Σ(bonds broken) - Σ(bonds formed).
𝑄 = 𝑚cΔ𝑇
Δ E system = - Δ E surroundings

Question 9

what is combustion?

Answer 9

a self sustaining chemical reaction occurs at temperatures above those of the surroundings. More simply, combustion is burning. and emits
h20 c02

Question 10

what are the properties of a combustion reaction?

Answer 10

Light and heat have been emitted.
New substances have been formed (carbon dioxide and water).
The process cannot be easily reversed

Question 11

if delta H is negative is it exo or endo thermic?

Answer 11

exothermic

Question 12

what is bond enthalpy?

Answer 12

amount of energy required to break 1 mol of a bond

Question 13

dont need to know

Answer 13

press perfect