Download presentation
Presentation is loading. Please wait.
Published byAnnabella Turner Modified over 9 years ago
1
Bell Work What do you use to convert grams to moles or moles to grams? What do you use to convert particles(atoms, molecules, units) to moles or vice versa? If I am changing from grams to particles what do I need to do? Convert 184g of PbI2 to particles.
2
Extra Credit-Memes! Create a meme that is related to chemistry.
To create a meme, go to a meme generator website. Choose a blank meme and add your own text. After you have created a meme save the image. Either me or print the image. You need to include 2-3 sentences describing the science behind your meme and why it is funny and clever. DUE BY MONDAY, DECEMBER 7
4
Unit 6: Chemical Reactions
5
What are indications that a chemical reactions has happened?
6
Bell Work List 5 things that would indicate a chemical reaction has occurred.
7
Indicators of chemical reactions
Emission of light or heat Formation of a gas Formation of a precipitate Color change Emission of odor
8
All chemical reactions:
Have two parts Reactants - the substances you start with 2. Products- the substances you end up with The reactants turn into the products Reactants ® Products
9
Describing Chemical Reactions
Can be described several ways: 1. In a sentence Copper reacts with chlorine to form copper (II) chloride. 2. In a word equation Copper + chlorine ® copper (II) chloride Cu + Cl2 ® CuCl2
10
Symbols used in equations
(s) after the formula –solid Cu(s) (g) after the formula –gas H2 (g) (l) after the formula -liquid H2O(l) (aq) after the formula - dissolved in water, an aqueous solution. CaCl2 (aq) Cu(s) + Cl2(g) ® CuCl2(aq)
11
Symbols used in equations
indicates a reversible reaction shows that heat is supplied to the reaction
12
Diatomic elements There are 7 elements that never want to be alone.
They form diatomic molecules, in gas state. H2 , N2 , O2 , F2 , Cl2 , Br2 , and I2
14
Law of Conservation of Mass
In a chemical reaction, matter is neither created nor destroyed. Atoms won’t change their identity (e.g. a Carbon atom can’t become an Iron atom) This means that you have to have the same number of each type of atom on each side of the chemical equation.
15
Law of Conservation of Mass
Atoms cannot be created or destroyed! Total mass stays the same. The atoms are rearranged to form new materials.
16
Balancing Equations We can see that the equation, does not follow the Law of Conservation of Mass C2 + O2 CO2 We can see that on the product side there are two carbon atoms, but on the reactant side there is only one. This cannot possibly happen, as mass cannot be destroyed
17
Balancing Equations To balance chemical equations follow these basic steps Perform an atom inventory—count how many of each element you have on each side of the arrow. Identify your problem areas Begin adjusting the coefficients of the equation to balance the equation. You cannot change the subscripts, only the coefficients!
18
Balancing Equations C2 + O2 CO2 Atom inventory Identify Problems
Fix Problems
19
WARNING! Don’t mess with the insides of polyatomic ions – put a square around them, or label them as X – treat the WHOLE polyatomic ion as though it were an element! Don’t ever play around with subscripts (those little numbers that tell you how many atoms are in a molecule) e.g. C6H22O11
20
7. H2 + Cl2 HCl 1H Cl2 2HCl
21
8. CdCO3 CdO + CO2 Already Balanced
22
4. Li + FeBr2 LiBr + Fe 2Li + 1FeBr2 2LiBr + 1Fe
23
3. KClO3 KCl + O2 2KClO3 2KCl + 3O2
24
NaOH + FeCl3 NaCl + Fe(OH)3
5. NaOH + FeCl3 NaCl + Fe(OH)3 3NaOH + 1FeCl3 3NaCl + 1Fe(OH)3
25
2. Na + H2O NaOH + H2 2Na + 2H2O 2NaOH + 1H2
26
6. Ca2Br2 + NaCO3 CaCO3 + NaBr 1Ca2Br NaCO3 2CaCO NaBr
28
Bell Work 12-6-15 Balance the following equations:
1.___Al2(SO4)3 +___ Ca(OH)2 →__ Al(OH)3 + __ CaSO4 2. ___Cr +___ O2 →____ Cr2O3
29
Types of Reactions Synthesis reactions Decomposition reactions
Single displacement reactions Double displacement reactions Combustion reactions
30
1. Synthesis General: A + B AB Example C + O2 + O O
Definition: multiple reactants combine to form a single product
31
2. Decomposition General: AB A + B Example: NaCl + Cl Na Cl Na
Definition: breakdown of one molecule into elements or simple compounds
32
3. Single Displacement/Replacement
Example: Zn + CuCl2 Zn Cl Cu + Cl Zn Cu + General: AB + C AC + B Definition: an element or ion is replaced by another in a compound
33
4. Double displacement General: AB + CD AD + CB Example: MgO + CaS
Definition: two elements or ions are replaced by another in multiple compounds
34
5. Combustion Reactions Definition: a hydrocarbon reacts with oxygen gas. This is also called burning!!! In general: CxHy + O2 CO2 + H2O Products are ALWAYS carbon dioxide and water.
35
Bell Work 12-8-15 1.Balance the equation 2. What type of reaction?
_____ Ca + _____ O2 _____ CaO Reaction: _______________ _____ Cu2O + _____ C _____ Cu + _____ CO2 _____ Na + _____ MgF2 _____ NaF + _____ Mg _____ Na + _____ HCl _____ H2 + _____ NaCl _____ Cl2 + _____ KI _____ KCl + _____ I2
36
Activity Series. Elements will replace elements below them in single rep. reactions. K Ca Na Mg Al Zn Fe Ni Pb H Cu Ag
38
Solubility Table Ion Solubility Exceptions NO3– soluble none ClO4– Cl–
except Ag+, Hg22+, *Pb2+ I– SO42- except Ca2+, Ba2+, Sr2+, Hg2+, Pb2+, Ag+ CO32- insoluble except Group IA and NH4+ PO43- OH– except Group IA, *Ca2+, Ba2+, Sr2+ S2- except Group IA, IIA and NH4+ Na+ K+ NH4+
39
AgNO3(aq) CuSO4(aq) Li3N NH4NO3
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.