... Balancing Chemical Equations, Schemes and Mind Maps of Cell Biology

Download ... Balancing Chemical Equations and more Schemes and Mind Maps Cell Biology in PDF only on Docsity! ... Balancing Chemical Equations OK. You know why you need to balance chemical equations, but you don't yet know how to do it. It turns out that I'm star who knows how to explain things in a way that even the dumbest people know how to follow. And, hey, if the dumbest people can figure it out, so can you! Listen: There are four easy steps that you need to follow to make this work. Here they are: 1. Get yourself an unbalanced equation. I might give this to you, or I might make you figure it out. Either way, if you don't have an equation with all the chemical formulas and the arrow and all that other stuff, then you're out of luck. 2. Draw boxes around all the chemical formulas. Never, ever, change anything inside the boxes. Ever!!! Really!!! If you do, you're guaranteed to get the answer wrong. 3. Make an element inventory. How are you going to know if the equation is balanced if you don't actually make a list of how many of each atom you have? You won't. You have to make an inventory of how many atoms of each element you have, and then you have to keep it current throughout the whole problem. 4. Write numbers in front of each of the boxes until the inventory for each element is the same both before and after the reaction. Whenever you change a number, make sure to update the inventory - otherwise, you run the risk of balancing it incorrectly. When all the numbers in the inventory balance, then the equation can balance. An example of equation balancing: Let's say I ask you the following thing on a test: "Balance the equation that takes place when sodium hydroxide reacts with sulfuric acid to form sodium sulfate and water." How do we solve this using the steps above? 1. Get yourself an unbalanced equation. Here's where you use your knowledge of formulas to help you out. If you know what the formula of sodium hydroxide, sulfuric acid, sodium sulfate, and water are, you'd be able to write the following unbalanced equation: 2. Draw boxes around all the chemical formulas. This is the step that people frequently don't do because they feel that it's a stupid thing to do. Those people are morons. Ignore them. You're drawing those boxes so that you'll be sure not to mess around with the formulas to balance the equation. While they all suffer in the pits of academic hell, you'll be laughing from the honor roll. Here's what the equation looks like: 3. Make an element inventory. In this inventory, your job is to figure out how many atoms of each element you have on the left and right sides of the equation. Now, if you look at the equation, you should be able to see that on the left side of the equation there is one sodium atom, five oxygen atoms (one from the sodium hydroxide, four from the sulfuric acid), three hydrogen atoms (one from the sodium hydroxide, two from the sulfuric acid), and one sulfur atom. On the right side of the equation, there are two atoms of sodium, one atom of sulfur, five atoms of oxygen (four from the sodium sulfate and one from the water), and two atoms of hydrogen. Thus, your element inventory should look like this: 4. Write numbers in front of each of the boxes until the inventory for each element is the same both before and after the reaction. Now, what happens when we put a number in front of a formula? Basically, anything in that box is multiplied by that number, because we're saying that we have that many of that kind of molecule. So, looking at the inventory, what should we do? Well, we can see that on the left side of the inventory, there is one atom of sodium and on the right there are two. The solution: Stick a "2" in front of the sodium hydroxide on the left side of the equation so that the numbers of sodium atoms are the same on both sides of the equation. When we do this, the new atom inventory should look like this: (I'll let you figure out how this is done) 2. _____FeCl3 + _____Be3(PO4)2 --> _____BeCl2 + _____FePO4 3. _____AgNO3 + _____LiOH --> _____AgOH + _____LiNO3 4. _____CH4 + _____O2 --> _____CO2 + _____H2O 5. _____Mg + _____Mn2O3 --> _____MgO + _____Mn 6. ____ NaBr + ____ CaF2  ____ NaF + ____ CaBr2 7. ____ H2SO4 + ____ NaNO2  ____ HNO2 + ____ Na2SO4 Writing Complete Equations Practice For each of the following problems, write complete chemical equations to describe the chemical process taking place. Important note: There are a few physical processes on this sheet – remember, you can’t write an equation for a physical process! 1) When lithium hydroxide pellets are added to a solution of sulfuric acid, lithium sulfate and water are formed. 2) When dirty water is boiled for purification purposes, the temperature is brought up to 100 0 C for 15 minutes. 3) If a copper coil is placed into a solution of silver nitrate, silver crystals form on the surface of the copper. Additionally, highly soluble copper (I) nitrate is generated. 4) When crystalline C6H12O6 is burned in oxygen, carbon dioxide and water vapor are formed. 5) When a chunk of palladium metal is ground into a very fine powder and heated to drive off any atmospheric moisture, the resulting powder is an excellent catalyst for chemical reactions.