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Balancing Equations. Chapter 6. What is balancing an equation?. Balancing an equation is changing the ratios of molecules/atoms to make the lowest possible same whole number and type of atoms on each side of the equation. Na + Cl 2 NaCl. 2. 2.
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Balancing Equations Chapter 6
What is balancing an equation? • Balancing an equation is changing the ratios of molecules/atoms to make the lowest possible same whole number and type of atoms on each side of the equation. • Na + Cl2 NaCl 2 2 • Note 4 Na + 2 Cl2 4 NaCl, would also have the same number but not the lowest possible ratio. It could be reduced!!
What you can not do! • You can NOT change the formula of the molecules I give you. • H2 + O2 H2O • you cannot change water to H2O2 (hydrogen peroxide) If the number is one, you don’t have to write it! 2 2 and this will make 2 water molecules you have to increase the amount of H on this side H H O O H O H H H O H H
What you are allowed to do • change the coefficient in front of any molecule/atom (changing the ratio of atoms) • ___ Ag + ___ Cl2 ___ AgCl • you can only write on those lines 2 2
Problem solving strategies • It helps to make a list of all atoms present • HCl + Ba(OH)2 BaCl2 + H2O 2 2 Ba – 1 H – 2 Cl – 2 O – 1 Ba – 1 H – 3 Cl – 1 O – 2 Start making the numbers agree one at a time (pick something, that occurs in only one molecule 1st) ~not H in this case Now going to O 4 2 4 2 Now everything is balanced! starting w/ Cl
Another to try 2 • CH4 + O2 H2O + CO2 • C- 1 C- 1 • H- 4 H- 2 • O- 2 O- 3 2 4 4 4 Everything is balanced now! This takes a lot of trial and error. Start with H now O
More Practice 2 • NH4ClO3 + CaSO4 • Ca(ClO3)2 + (NH4)2SO4 • If and ONLY IF a polyatomic ion is on both sides of an equation, you can treat it like it is one thing!
Polyatomic ions • NH4Cl+ NaOH NH3 + NaCl + H2O • Now you can’t treat the polyatomic ions as though they are one thing because the same polyatomic ion isn’t on both sides. • This equation is already balanced with no coefficients.
Nitrogen Triodide 3 2 • NI3 N2 + I2 • N- 1 N- 2 • I- 3 I- 2 2 6 6
A Big Problem 10 8 2 5 4 13 • C4H10 + O2 H2O + CO2 • C- 4 C- 1 • H- 10 H- 2 • O- 2 O- 3 4 8 8 20 10 20 26 26 9 13 18 I can’t increase by 6.5 only whole numbers, I have to make O even on the product side. And finally everything balances!!
More • (NH4)2CO3 + Al(NO3)3 Al2(CO3)3 + NH4NO3 3 2 6
One More • C6H14 + O2 H2O + CO2 2 19 14 12