Potassium Bromide + Lead II Nitrate
I know its PbBr2 + KNO3 but how do you set up the the original compounds and do double replacement?
I know its PbBr2 + KNO3 but how do you set up the the original compounds and do double replacement?
-
In the reactant side of the equation you will need to turn the word equation into the formula equation. I would also suggest you mention that each reaction species in its ionic state is aqueous.
You must consider the ionic charges or oxidation states of each ion as well. On the reactant side, when the positive metal ions (cations) exchange with the negative non-metal ions (anions) the new products will form. If a gas or precipitate is formed you will observe bubbles or a cloudy, often colored solid cloudy substance form. (Transition metal ions are known for their colors, depending on what oxidation state they represent.) It would be helpful to know your solubility rules in order for you to determine which products remain aqueous and which products precipitate out. Generally the heavy metal ions precipitate out unless they are formed with nitrates.
In this problem, when the products form K will drop Br and form with NO3 and Pb will drop NO3 and join with Br. The new subscripts can be determined by the oxidation number or charge of the ions that are newly formed with each other. Put the oxidation state of the new anion (number only, not charge) as the new subscript for the cation and use the new cation oxidation state (number only, not charge) as the new subscript for the anion; do this for both new product pairs. So the new products will arise the following way:
K has a +1 charge, NO3 has a -1 charge so so KNO3 will combine as one product species; we don't write ones as subscripts. This will not for a precipitate as all alkali metals are aqueous. The other new product pair is Pb with a +2 charge and Br with a -1 charge so it will be PbBr2. Use your periodic table to determine the oxidation states or charges and a polyatomic ion chart to find the ionic charge of the polyatomic ions. Its good to memorize these charts form the more simple polyatomic ions and to realize that the ionic charges of the monatomic ions are periodic trends. +1 for Group 1(lithium family), +2 for Group II (Beryllium family), +3 for group 3 (Al family) start with Nitrogen family and they are generally -3, Oxygen family is -2, fluorine family (halogens) is -1,
You must consider the ionic charges or oxidation states of each ion as well. On the reactant side, when the positive metal ions (cations) exchange with the negative non-metal ions (anions) the new products will form. If a gas or precipitate is formed you will observe bubbles or a cloudy, often colored solid cloudy substance form. (Transition metal ions are known for their colors, depending on what oxidation state they represent.) It would be helpful to know your solubility rules in order for you to determine which products remain aqueous and which products precipitate out. Generally the heavy metal ions precipitate out unless they are formed with nitrates.
In this problem, when the products form K will drop Br and form with NO3 and Pb will drop NO3 and join with Br. The new subscripts can be determined by the oxidation number or charge of the ions that are newly formed with each other. Put the oxidation state of the new anion (number only, not charge) as the new subscript for the cation and use the new cation oxidation state (number only, not charge) as the new subscript for the anion; do this for both new product pairs. So the new products will arise the following way:
K has a +1 charge, NO3 has a -1 charge so so KNO3 will combine as one product species; we don't write ones as subscripts. This will not for a precipitate as all alkali metals are aqueous. The other new product pair is Pb with a +2 charge and Br with a -1 charge so it will be PbBr2. Use your periodic table to determine the oxidation states or charges and a polyatomic ion chart to find the ionic charge of the polyatomic ions. Its good to memorize these charts form the more simple polyatomic ions and to realize that the ionic charges of the monatomic ions are periodic trends. +1 for Group 1(lithium family), +2 for Group II (Beryllium family), +3 for group 3 (Al family) start with Nitrogen family and they are generally -3, Oxygen family is -2, fluorine family (halogens) is -1,
-
You need to know the charges of the ions (and you probably do).
K is +1 Br is -1 Pb is +2 and NO3 is -1
So, 2 KBr + Pb(NO3)2 -----------> PbBr2 + 2 KNO3
K is +1 Br is -1 Pb is +2 and NO3 is -1
So, 2 KBr + Pb(NO3)2 -----------> PbBr2 + 2 KNO3