Synthesis+R.+Stacey

Synthesis Reaction 

The first type of reaction is synthesis. A synthesis reaction, also called a combination reaction, is when two unique molecules come together to form one compound. When you look at an equation, it generally looks like this: ** A + B ** ** → **** AB ** The //** A **// and //** B **// represent the reactants, and the // AB // represents the product. This reaction is easiest to see. * Sometimes we are given the equation, other times we are given the sentence. In a sentence to equation situation, you find the reactants and the products first. So for example, you may see this: // When Magnesium is burned in pure oxygen gas, it reacts to form magnesium oxide. // 1) First we look at the word and find the element names and the product.  v  So you see Magnesium, pure oxygen gas, and magnesium oxide. Another big part is the " REACTS TO FORM " these words indicate an arrow and anything after this phrase is the product.

2) So then, we go back to the elements and find their symbols: So it would look like Mg (s) + O(g) → Magnesium Oxide (we'll find this later) 3) After you find this, you need to find the elements' charges so that you can begin to balance the equation.  v  We know that since Magnesium is in Group 2, it will be +2.  v  Oxygen is in group 16, so it will have a -2 charge. We also know that when Oxygen is alone, it is diatomic, meaning that it will have a 2 next to it: O2  v  So now we have Mg(s) + O2(g) → Magnesium Oxide (we will find this part later)  v  Next, we need to find what Magnesium Oxide is. Well, we see that oxygen is the anion, meaning it is negative. So it will be Mg(s) + O2(g) → MgO. Right?  v  So we see that there are 2 Oxygen’s on the left, so we need two on the right; which gives the entire compound a '2'. Mg(s) + O2(g) --> 2MgO. Now, we need to balance Magnesium, since there are 2 of them on the right. That means that we have one more step:  v  The Mg needs a 2 in front of it as well, so that the equation is completely balanced. And now we can check ourselves by seeing if we began and ended with the same amount of 'stuff''.  v  Now we are completely balanced! Yay!  J
 * NO ** we still need to balance it. When we try to balance an equation, it means that we need the same amount of 'stuff' on each side.

magnesium burning in Oxygen gas and the second picture shows magnesium oxide, the product, which is a powdery substance.

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