For reaction (II) Pb (NO3)2 + 2KI -> PbI2+2KNO3 Lead nitrate is soluble, so it gets written as ions. The same goes for potassium iodide and potassium nitrate. Complete Ionic equation: 2 K+1 + I-1 + Pb2+ + NO32- -> PbI2 + 2K+1 + NO3-1 Net Ionic Equation: Pb+2 + 2 I-1 -> PbI2 Warm-Up Exercise 2 In this lab you will mix 25 mL of 0.05M lead nitrate with 1.4 mL of 0.025M sodium carbonate. After the reaction occurs, you will filter the solution to remove the precipitate. You will then test the remaining solution for excess lead ion and for excess carbonate ion… Imagine that you mix the two volumes and then freeze frame the reaction so the it does not proceed: 1.
Therefore compounds H2O, cyclohexane, C, and D are molecular compounds. Later testing the solubility of the compounds the lab results were the following. Solubility in water: compound A dissolved partially, compounds B and D dissolved nearly none, while compounds C and E dissolved freely in water. Solubility of the compounds in cyclohexane were: H2O nearly non dissolved so it formed layers of the two compounds, compounds A, B and C nearly non dissolved, while compound C partially dissolved, and compound D freely dissolved in cyclohexane. Finally arranging the compounds in order of increasing melting points are: Compound C with 187.06 °C, followed by compound D with 195.31, and Compound A, B and
(2) Although NH3 forms OH- with water, it did not donate any proton to form OH- but only gain. Therefore, it is a Bronsted-Lowry base but not an Arrhenius base 11. Define the following terms: (5) a. strong acid: acid that
03.06 Covalent Bonding and Lewis Structures: Pre-Lab and Rubric Before You Begin: You may either copy and paste this document into a word processing program of your choice or print this page. Research the answers to the following questions on the internet and write your answers in your own words. For each answer, include the address of the web site (or title and author of a book or article) that you used to help you answer the question. Which type of compound usually has higher melting points: ionic compounds or covalent compounds? What is the reason for this difference in melting points?
Lewis diagram: Non-metal oxides -called acidic anhydrides (anhydride means “without water”) -these react with water to form molecular acids containing H+ E.g. SO3(g) + H2O(l) ( H2SO4(aq) Note: H2CO3 is too unstable to be isolated as a pure compound. CO is not an acidic anhydride. Bases: Two categories 1) Ionic compounds that contain hydroxide ions or O2- 2) Molecular compounds that react with water to give hydroxide ions Bronsted-Lowry Theory of Acids and Bases -acids are proton donors -bases are proton acceptors -acid-base reactions involve an proton transfer from acid to base -involves conjugate acid-base pairs e.g. NH3 and CH3COOH Note: Conjugate acid-base pairs differ by one proton and a charge of 1 Amphoteric/Amphiprotic -a substance capable of reacting as an acid or a base -water in the above examples is amphoteric -another example is HCO3-1 which is part of the buffer system in our blood Polyprotic Acids -acids that have more than one ionisable hydrogen e.g.
It is a physical equilibrium since the water molecules have only changed from liquid to vapor. Chemical equilibria on the other hand involve changes in the chemical composition of substances. Bond breaking and bond formation is involved. An example would be the dissociation of acetic acid. There is an interchange of particles between ions and molecules whose rate of exchange becomes equal when equilibrium is established.
Besides that, along the period 3 from left to right, there is increasing of acidity and decreasing of basicity, decreasing of metallic character, and decreasing of electronegativity difference. The trend in structure is from the metallic oxides containing giant structures of ions, a giant covalent oxide (silicon dioxide) in the middle and molecular oxides on the right. In the change of bonding, Na2O, MgO and Al2O3 have giant ionic bond while Al2O3 has giant molecular bond. But for P4O10, SO2 and Cl2O have simple molecular bond. The decreasing of metallic character is because of the increasing nuclear charge since metallic character is a measure of the ease of loss of electrons from the outer shell.
| 3 drops of 1% dimethylglyoxime solution. | [Ni(NH3)6]2+ + 2H2DMG→ Ni(HDMG)2 + 2NH4+ + 4NH3 | 9 Al3+ | By heating the solution in the hot water bath. | A black gelatinous precipitate was changed to colorless. | 6M NH3 | [Al(OH)4]- + 4H+ → Al3+ + 4H2O | 10 | Centrifuge the solution. | Colorless solution.
A. barium sulphate B. calcium carbonate C. silver chloride D. sodium nitrate 3. An element X forms a hydroxide, which dissolves, both in acids and in alkalis. What could X be? A. aluminium B. calcium C. copper D. iron 4. In which reaction is dilute sulphuric acid not behaving as an acid?
This occurs when the solution is saturated. • The equilibrium constant, the Ksp, is no more than the product of the ions in solution. (Remember, solids do not appear in equilibrium expressions.) • For a saturated solution of AgCl, the equation would be: AgCl(s) Ag+(aq) + Cl−(aq) • • The solubility product expression would be: Ksp = [Ag+][Cl−] The AgCl(s) does not appear in the equilibrium expression since solids are left out. Why?