WRITING AND. Martha Andreski. BALANCING. EQUATIONS. I. CHEMICAL EQUATIONS. …are expressions of reactions (rxns) They consist of 2 parts: REACTANTS PRODUCTS left "yields" right
I. CHEMICAL EQUATIONS
…are expressions of reactions (rxns)They consist of 2 parts:
left "yields" right
ie: lead (II) nitrate and potassium iodide react to form lead (II) iodide and potassium nitrate
Pb(NO3)2 + KI PbI2 + KNO3
Before balancing, there are 2 H’s on the left and 2 H’s on the right;
There are 2 O’s on the left but only one O on the right.
So we must add oxygens to the right but we can only do this by changing the coefficient in front of the molecule “H2O”
But now the H balance on the left is thrown off, so you must change that coefficient to a 2
Now, work on the Balancing Equations Practice Sheet. Finish for homework.
React with cold H2O and acids, replacing H2
React with acids or steam but usually not H2O(l), to replace H2
React with acids but not H2O(l) to replace H2
All react with O2 to form oxides