Living By Chemistry SECOND EDITION Unit 4 TOXINS

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Living By Chemistry SECOND EDITION Unit 4: TOXINS Stoichiometry, Solution Chemistry, and Acids and

Living By Chemistry SECOND EDITION Unit 4: TOXINS Stoichiometry, Solution Chemistry, and Acids and Bases

Lesson 90: Solid Evidence Precipitation Reactions

Lesson 90: Solid Evidence Precipitation Reactions

Chem. Catalyst Kidney stones are solid blockages that sometimes occur in the kidney. Below

Chem. Catalyst Kidney stones are solid blockages that sometimes occur in the kidney. Below is the chemical equation for a double exchange reaction between calcium chloride and sodium oxalate that results in the formation of one type of kidney stone. Ca. Cl 2(aq) + Na 2 C 2 O 4(aq) 2 Na. Cl(aq) + Ca. C 2 O 4(s) a. What do you expect to see in the beaker if you complete this reaction? b. Which compound is the kidney stone? What is your reasoning?

Key Question Which substances precipitate from aqueous solutions?

Key Question Which substances precipitate from aqueous solutions?

You will be able to: • explain what a precipitation reaction is • write

You will be able to: • explain what a precipitation reaction is • write net ionic equations for precipitation reactions

Prepare for the Lab Work in pairs. Precipitate: A solid produced in a chemical

Prepare for the Lab Work in pairs. Precipitate: A solid produced in a chemical reaction between two solutions.

Discussion Notes Ca. Cl 2(aq) + Na 2 C 2 O 4(aq) 2 Na.

Discussion Notes Ca. Cl 2(aq) + Na 2 C 2 O 4(aq) 2 Na. Cl(aq) + Ca. C 2 O 4(s) The mixing of two ionic solutions sometimes results in the formation of a solid precipitate. Precipitation is not limited to solids. The degree to which a compound dissolves in water is called its solubility.

Discussion Notes (cont. ) Solubility varies from compound to compound. Solubility Trends Anions NO

Discussion Notes (cont. ) Solubility varies from compound to compound. Solubility Trends Anions NO 3– CL– OH– SO 42– CO 32– C 2 O 42– PO 43– Most alkali metals, such as Li+, Na+, K+, NH 4+ S S S S Most alkaline earth metals, such as Mg 2+, Ca 2+, Sr 2+ S S N N N Period 4 transition metals, such as Fe 3+, Co 3+, Ni 2+, Cu 2+, Zn 2+ S S N N N Other transition metals, such as Ag+, Pb 2+, Hg 2+ S N N N

Discussion Notes (cont. ) There are positive and negative aspects to the solubility of

Discussion Notes (cont. ) There are positive and negative aspects to the solubility of toxic substances. Once a substance is absorbed, it may be difficult for the body to get rid of it through its natural filtration systems, the kidneys and the liver.

Wrap Up Which substances precipitate from aqueous solutions? • Precipitation depends on solubility; compounds

Wrap Up Which substances precipitate from aqueous solutions? • Precipitation depends on solubility; compounds that are not very soluble tend to form precipitates. • Mixing two aqueous salt solutions often results in the formation of a precipitate. • Soluble substances can interact with the human body in either positive or negative ways.

Check-In A solution of K 2 SO 4 is mixed with a solution of

Check-In A solution of K 2 SO 4 is mixed with a solution of Pb(NO 3)2, and a precipitate forms. a. Write the chemical equation for this reaction. b. What is the precipitate that forms? How do you know?