chemical reaction

Még több ilyen

RESPONSIBLECONSUMPTION ANDPRODUCTION

Szerző: Arife Eroğlu

Create a food chain and food web of any habitat

Szerző: LEE YAN YING, VION N/A

Macromolecules Concept Map

Szerző: Laura McGuire

Chemical Energy

Szerző: John Doe

chemical reaction

Energy in Chemical Reaction

Energy Change During ReactionsDuring chemical reactions old bonds are broken and new bonds are made.

-Energy can be taken in from the surrounding.
- Energy can be given out to the surrounding.This energy can be in forms of:
- Heat
- Light
- Sound
- Electricity

∆H - the symbol of difference in energy. ∆ is Greek capital letter “delta”, and is used to mean, “change”. It is used in Science & Maths. H represents energy and is sometimes called “enthalpy”

∆H = energy of products – energy of reactants

If the reactants contain more energy than the products , heat is given out (exothermic) , and ∆H will be negative . If the products contain more energy than the reactants , heat is taken in (endothermic) , and ∆H will be positive . ∆H = energy of products – energy of reactants - ENDOTHERMIC = ∆H is positive - EXOTHERMIC = ∆H is negative

Exothermic:  Heat is given out  Reactants cool down  ∆H is negative

Endothermic:  Heat goes in  Reactants heat up  ∆H is positive

Energy Change During ReactionsDuring chemical reactions old bonds are broken and new bonds are made. -Energy can be taken in from the surrounding. - Energy can be given out to the surrounding.This energy can be in forms of: - Heat - Light - Sound - Electricity

When chemical bonds are broken energy is needed to break the bonds.

chemical equations

Every chemical has a symbol, alway begin with a capital letter; the 2 letter is alway small

Reactant - chemicals that start the reactant
Product - chemicals produced by the reaction

Ex: CO2 = 1 carbon + 2 oxygen

Reactant - chemicals that start the reactant Product - chemicals produced by the reaction

Chemical Reactions

metal + oxygen = metaloxide (General Equation)

Conclusion: metal + acid = salt + hydrogen Magnesium reacts with sulfuric acid to form magnesium sulfate and hydrogen: Ex: Mg (s) + H2SO4 (aq) = MgSO4 (s) + H2 (g) Magnesium Sulfuric acid Magnesium sulfate Hydrogen Metal Acid Salt Hydrogen

Conclusion:metal oxide + acid = salt + water -metal hydroxide + acid = salt + water -metal carbonate + acid = salt + water + carbon dioxide -

Reactions between Metals and Water Alkali metals – group 1 Ex: lithium + water = lithium hydroxide + hydrogen 2Li (s) + 2H2O (l) = 2LiOH (aq) + H2 (g) Lithium floats on water. It fizzes and becomes smaller until it disappears

Reactions between Earth Alkali Metals and Water Earth Alkali metals – group 2 Ex: magnesium + steam = magnesium oxide + hydrogen Mg (s) + 2H2O (g) = Mg(OH)2 (aq) + H2 (g)

Atomic Structure

Reaction between Metal and Oxygen

Metal + Oxygen (reactants) = Metaloxide (product)

Reactivity: Because of the atomic structure of the metals; Groups 1 and 2 are more reactive as you go down the group. Valence electrons are easier to get lose since they are further away from the nucleus; This means more reactive.

Potassium Atomic structure - 2,8,8,1 4 shells - Period 4 1 valence electron - Group 1