This question is very confusing, I do not understand what it wants me to do.
Each reaction below has been identified by type. Use this information to help predict products. Copy and then complete each equation by writing the products of the reactions. Remember to include subscripts and parentheses when required.
This is what I did, not quite understanding what I was supposed to do.
A) Al + F2 --> Synthesis
Products: 1 atom of aluminum metal, 2 molecules of fluorine gas.
2Al + 3F2 --> 2AlF3
B) K+O2 --> Synthesis
Products: 1 atom of potassium metal, 2 molecules of oxygen gas.
4K + O2 --> 2K2O
C) C2H6+O2 --> Combustion
Products: hydrocarbon, oxygen
C2H6 + 4O2 --> 2CO2 + 3H2O
D) C6H12O4 + O2--> Combustion
Products: Carbon, hydrogen, Oxygen
C6H12O4 + 7O2 --> 6CO2 + 6H2O
Is this what I'm supposed to do, or am I totally off track?
14 answers
Each reaction below has been identified by type. Use this information to help predict products. Copy and then complete each equation by writing the products of the reactions. Remember to include subscripts and parentheses when required.
It also says use the charges from a periodic table. I don't get what I'm supposed to do.
I get the product part now, thanks bobpursely, but have I done the rest of it correct, because I have balanced those equations, and it doesn't ask me in the question to do that, so I'm very unsure of what do do or not.
I believe you have misinterpreted the question. Your answers for the type of reaction appear to be correct. The products appear to be correct. The balanced equations appear to be correct. What you have not done is to name the PRODUCTS. You have named the reactants and called them products. The products are on the right side of the arrow; the reactants are on the left side of the arrow. For example, in the example to which Bob P responded, the product is aluminum fluoride as he points out. You named the reactants as products but you wrote the equation correctly and balanced it.
Products: 2 molecules of aluminum fluoride
2Al + 3F2 --> 2AlF3
B) K+O2 --> Synthesis
Products: 2 molecules of Potassium oxide
4K + O2 --> 2K2O
C) C2H6+O2 --> Combustion
Products: Carbon dioxide, water
C2H6 + 4O2 --> 2CO2 + 3H2O
D) C6H12O4 + O2--> Combustion
Products: Carbon dioxide, water
C6H12O4 + 7O2 --> 6CO2 + 6H2O
Products: 2 molecules of Carbon dioxide, 3 molecules of water
C2H6 + 4O2 --> 2CO2 + 3H2O
D) C6H12O4 + O2--> Combustion
Products: 6 molecules of Carbon dioxide, 6 molecules of water
C6H12O4 + 7O2 --> 6CO2 + 6H2O
sorry I forgot to mention how many molecules before.
Rb2O --> Decomposition
Rb + O2
I don't know what to do rest.
1. Usually one balances an equation unless specifically told not to do so.
2. I don't think the question asks you to identify the number of molecules. I think it is sufficient to write, for example, aluminum fluoride, or carbon dioxide and water. I think the idea is for you to know the names of the compounds. Besides, there isn't enough information given to suggest 2 molecules of aluminum fluoride. It COULD be 2 moles or 2 grams and not 2 molecules.
3. Decomposition is the reverse of synthesis. In synthesis, the first question with Al and F2, you take two or more reactants and make a smaller number of particles. (You took two reactants and made one product). In decomposition reactions, you take one reactant and break it apart into two or more products. 2Rb2O ==> 4Rb + O2
Could you also show me how to do the double replacement thing. The obly reactions I am getting how to do are synthesis and combustion. I need to practise alot on the other ones. Could you please show me step by step how you balance this equation. Thank you very much for your assistance DrBob222.
For ex.
C6H12O4 + 7O2 --> 6CO2 + 6H2O
This equation here is balanced. But on the right side the coefficients 6 and 6 equal up to 12, isn't the left side also supposed to add up to that number. Because on the left side there is an invisible 1 coefficient infront of the C and + 7; that adds up to 8. 12 and 8 don't match, aren't they supposed to?
I hope you understand what I'm trying to say, because that's the main thing that has been confusing me all that time.
BaCl2 + Pb(NO3)2
I know that there is an invisible 1 infront of Ba, and that Cl is 2, but say if there wasn't that 2 there, then would there be an invisible 1 coeffient infront of Cl?
First, C6H12O4 + 7O2 --> 6CO2 + 6H2O , note that equations are balanced by using various coefficients (which you already know) and not changing subscripts (which you already know). Equations are balanced when
a. # atoms on the left equal # atoms on the right.
b. charge on the left equals charge on the right.
c. In redox reactions, the change in electrons must be equal; i.e., electrons lost must equal electrons gained (but you haven't had any of this yet although you have balanced some redox equations but you have done them by inspection).
d. BUT the moles do not need to balance. Grams are conserved but not moles. So in this equation,
C6H12O4 + 7O2 --> 6CO2 + 6H2O , there are 8 molecules on the left and 12 on the right. No problem if the atoms balance as they do and the charges balance as they do.
For the double replacement,
BaCl2 + Pb(NO3)2 ==>
just change places with the + and - charges. Move the Ba so it combines with NO3 and move the Pb so it combines with the Cl. It's that simple.
BaCl2 + Pb(NO3)2 ==> Ba(NO3)2 + PbCl2
and it is balanced as is.
About the 1s.
Yes, there is an invisible 1 as a coefficient in BaCl2 (as well as Pb(NO3)2). And there is an invisible 1 AFTER Ba in BaCl2. I might rewrite it this way.
Ba1Cl2.
However, we don't write the subscript 1 for the same reason we don't write the coefficient 1. Ba MEANS 1Ba1. There is NEVER a coefficient inside a compound; that is, BaCl2, if written as Ba1Cl2, the 1 ALWAYS refers to the atom BEFORE it just as the 2 refers to the Cl(the atom BEFORE it. One thing that is so confusing to beginners is that we write BaCl2 when we mean BaCl2 and the student must understand that numbers following an atom means it is a subscript [Ba(NO3)2 is an example in which both the 3 and the 2 are subscripts. The 3 means we have 3 O atoms...there is an invisible 1 following the N...and the 2 is a subscript meaning to multiply everything inside the parentheses by 2.
The student also understands that numbers placed BEFORE a molecule are coefficients and that no number means 1.
2Ba(NO3)2. The first 2 is a coefficient, the first three and second 2 are subscripts.