Presentation on theme: "By Rosie Langello, Hannah Moyer, Katie Brandt, and Nichole Weaver."— Presentation transcript:
By Rosie Langello, Hannah Moyer, Katie Brandt, and Nichole Weaver
Double Replacement: A chemical reaction in which two compounds exchange positive ions and form new ions to form two new compounds
The Generic Equation of Double Replacement The generic equation for Double Replacement is: AB(aq)+XY(aq) AY(s)+XB(aq)
EXAMPLES! Silver nitrite and potassium chloride Baking Soda and Vinegar Cake : Baking soda (NaHCO3) reacts with acidic substances (HA) in cake batter in a double replacement reaction: NaHCO3 + HA --> Na A + H (HCO3) H(HCO3) is more commonly know as H2CO3. It decomposes into CO2 and Water. The CO2 is responsible for making the cake rise.
What happens during a double replacement reaction Double Replacement Reactions A typical double replacement reaction occurs when two ionic compounds are mixed together. In water these ionic compounds split apart into their respective anions and cations. The cations now have an opportunity to swap anions. A reaction occurs if, by swapping anions, a product is formed that can no longer split apart. AgNO 3(aq) + KCl (aq) > AgCl (s) + KNO 3(aq) The reaction must be driven by one of three driving forces: Formation of a solid, formation of a gas or formation of a weakly ionizing compound such as water. NaNO 3(aq) + KCl (aq) X > NaCl (aq) + KNO 3(aq) Nothing happens!! Without a driving force there is no change in the solution so we say no reaction has taken place. *Note that even though we can write an equation for the reaction, no reaction takes place without a driving force
Activity Invite girl A and boy B to begin dancing. Also, invite a boy C and a girl D as well to the open area in the classroom. Instruct boy C and girl D to also dance. As they dance, explain to the other students that there are now two different products dancing in the classroom. Next, instruct girl A to leave boy B to dance with boy C. Also, instruct boy B to begin dancing with girl D. Explain to the students that another chemical reaction has taken place. A reactant and a reactant have switched into 2 new products. AB + CD- >AC + BD. This is an example of a double replacement reaction.