I am having trouble understanding how to come up with the products for single replacement reactions. Can any one check my work and tell me what i am doing, and also point out if i am missing any rules.
1. KI + Cl2 --->
2. Fe + HCl --->
3. Zn + HNO3 --->
For number 1 i came up with
2KI + Cl2 ---> 2KCl + I2
Correct answer is KCl + I2 <- now in that shouldn't chlorine be 2 to balance it out?
For number 2 i came up with
Fe + HCl ---> H2 + FeCl
Correct answer is
2 Fe + 6 HCl ---> 2 FeCl3 + 3 H2
How did Cl get 3 atoms on right.. completely lost on this one
For number 3 i came up with
2 Zn + 2HNO3 --> H2 + 2ZnNO3
Correct answer is
Zn + 2HNO3 --> Zn(NO3)2 + H2
You have #1 correct.
#2. Fe is +3 oxidation start (valence) so the formula for iron chloride is FeCl3. Then you balance it as the answer shows.
#3. Same problem. Zn has oxidation state (valence) of +2; therefore, zinc nitrate is Zn(NO3)2 and you balance from there.
To determine the correct products for single replacement reactions, it is important to understand and apply some key rules. Let's go through each of the reactions you provided:
1. KI + Cl2 --->
Your answer: 2KI + Cl2 ---> 2KCl + I2
In this case, your answer is correct. The reaction between KI and Cl2 results in the formation of KCl and I2. It is important to balance the equation by ensuring there are the same number of atoms on both sides. Since chlorine (Cl) is diatomic (exists as Cl2), the balanced equation becomes:
2KI + Cl2 ---> 2KCl + I2
2. Fe + HCl --->
Your answer: Fe + HCl ---> H2 + FeCl
In this case, you missed the balancing of the hydrogen (H) and iron (Fe) atoms. The reaction between iron (Fe) and hydrochloric acid (HCl) results in the formation of hydrogen gas (H2) and iron chloride (FeCl3). To balance this equation, you need to ensure the number of atoms on both sides is the same:
2 Fe + 6 HCl ---> 2 FeCl3 + 3 H2
This balanced equation shows that 2 iron atoms react with 6 hydrochloric acid molecules to produce 2 iron chloride molecules and 3 molecules of hydrogen gas.
3. Zn + HNO3 --->
Your answer: 2 Zn + 2HNO3 --> H2 + 2ZnNO3
In this case, you correctly identified zinc (Zn) as the active metal. However, the reaction with nitric acid (HNO3) forms zinc nitrate (Zn(NO3)2) rather than simply zinc nitrate. The balanced equation is:
Zn + 2HNO3 --> Zn(NO3)2 + H2
This equation shows that zinc reacts with 2 molecules of nitric acid to produce 1 molecule of zinc nitrate and 1 molecule of hydrogen gas.
Overall, it is important to balance the equation by ensuring that the number of atoms on both sides is the same. Pay attention to the charges and valences of the elements involved to determine the correct products.