Chemistry 04.03 Single and Double Replacement Reactions
The model for a single replacement reaction: A + BC → AC + B What do A and BC represent? How does replacement occur?
A is a neutral element and BC is an ionic compound. Positive ion A replaces the positive ion B in the ionic compound. A and C bond together, leaving B as a neutral element by itself.
The model for a double replacement reaction: AB + CD → AD + CB What do A, B, C, and D represent? What do A and C and B and C have in common? What do AD and CB represent?
A, B, C, D in the reactants represent ions. A and C are positive ions and B and D are negative ions.AD and CB represent ionic or molecular compounds that are formed.
Why do scientists use an activity series to determine if a single replacement reaction will occur?
An activity series lists the elements in order of reactivity. In a single replacement reaction, a reaction will occur if the replacement element is more reactive (higher on the activity list) than the element it is trying to replace.
What is an application of a double replacement reaction?
An application of a double displacement reaction is seen during the neutralization of an acid using a base. This is also called an acid-base reaction.
What is the advantage of conducting double replacement reactions in aqueous solutions?
Because the reactants are dissolved in water, they can move and collide together to form new products.
Describe what happens in each step of the following double replacement reaction: Al(NO3)3 + 3NaOH
Beginning Reactions: the positive ions of the reactants switch positions to create the products (Al(NO3)3 + 3NaOH) Ion Breakdown: each ion is given an appropriate subscript to keep charges balanced in each chemical formula (Al3, (NO3)-, Na+, OH-) Balanced Equation: coefficients are used to balance the overall equation (Al(OH)3 + 3NaNO3)
Describe the nature of the reactants and products in a double replacement reaction.
In a double replacement reaction, the reactants are always two compounds, and the products are always two different compounds.
Describe what happens during a neutralization reaction.
It's a double displacement reaction in which the positive ions from one reactant take the place of the positive ions in the other reactant.
What are some characteristics of single replacement reactions?
One element replaces another element in a compound to form a new substance. Single replacement reactions have the same number of reactants as products.
Describe the nature of the reactants and products in a single replacement reaction.
The reactants in a single replacement reaction are always an element and a compound, and the products are a different element and a different compound.
What is a single replacement (displacement) reaction?
a type of reaction in which one element replaces a similar element within a compound
What is a double replacement (displacement) reaction?
a type of reaction in which the ions of two compounds exchange places in an aqueous solution to form two new compounds
Classify the reactions in the equations below. H2SO4 + 2NaOH → Na2SO4 + 2H2O
acid-base reaction
Give an example of how an acid-base reaction forms ionic salt.
an acid (HCl) reacts with a base (NaOH) to form a salt (NaCl) and water: When an acid and a base react in this double replacement reaction, H+ & OH- combine to form HOH, or H2O. The other ions involved in the reaction combine to form the ionic salt.
Classify the reactions in the equations below. Al(NO3)3 + 3NaOH → Al(OH)3 + 3NaNO3
double replacement
Describe the products formed from double replacement reactions in aqueous solutions. molecular product
ex: water
Describe the products formed from double replacement reactions in aqueous solutions. insoluble product
insoluble in water, but it bubbles out of the solution as a gas instead of forming a solid precipitate
For the following reactions, use the activity series list to determine if a reaction will occur and what products will be formed. MgCl2 + Zn Mg + Co(NO3)2 Ni + CuCl2 Zn + Pb(NO3)2 Al + KBr
no reaction Mg(NO3)2 + Co NiCl2+ Cu Zn(NO3)2 + Pb No reaction
Describe the products formed from double replacement reactions in aqueous solutions. solid precipitate
not very soluble in water, it will not stay dissolved in the aqueous solution
Classify the reactions in the equations below. 2Al + 3H2O → Al2O3 + 3H2
single replacement
Provide an example of a neutralization reaction.
when hydrochloric acid and sodium hydroxide react with one another: A positive sodium ion in sodium hydroxide will take the place of the hydrogen ion in hydrochloric acid. The positive and negative ions in each reactant have switched partners to produce the products water and a salt.
