1. Test 8 % grade = ___. 2. I studied by … 3. Next time I will study by … 4. Goal for next time = ____  If you did not meet your goal it stays the same as last time  If you did meet your goal improve upon your score by at least 1 point Day

Describing Chemical Reactions Chemical Reactions – a process in which one or more substances are converted into new substances with different physical and chemical properties Bonds break, and/or form, and/or rearrange!!!

H 2(g) + F 2(g) 2HF (g) Chemical equation reactantsproducts Describing Chemical Reactions Reactions are represented by chemical equations

H 2(g) + F 2(g) 2HF (g) reactantsproducts Describing Chemical Reactions State of matter: g = gas, l = liquid, s = solid, aq = aqueous solution

H 2(g) + F 2(g) 2HF (g) reactantsproducts Describing Chemical Reactions Coefficients – how many mols of each element react with each other – mol ratio

H 2(g) + F 2(g) 2HF (g) Describing Chemical Reactions 1 mol of hydrogen gas reacts with 1 mol of fluorine gas to produce 2 mols of hydrogen fluoride gas For now think of a mol as a piece: 1 piece of hydrogen gas reacts with 1 piece of fluorine gas to produce 2 pieces of hydrogen fluoride gas

Atoms are neither created nor destroyed in ordinary chem. rxns. Describing Chemical Reactions Conservation of matter -

Describing Chemical Reactions A heads-up on diatomic gases: If the natural state of an element is gas, assume it is always a diatomic molecule (Example: Nitrogen = N 2 )

Chemical Reactions – What’d We Just Do? Bonds … a process in which one or more substances are converted into new substances with different physical and chemical properties

H 2(g) + F 2(g) 2HF (g) Chemical equation reactantsproducts What’d We Just Do?

H 2(g) + F 2(g) 2HF (g) reactantsproducts State of matter: g = gas, l = liquid, s = solid, aq = aqueous solution What’d We Just Do?

H 2(g) + F 2(g) 2HF (g) reactantsproducts Coefficients – how many mols of each element react with each other – mol ratio What’d We Just Do?

Solid lithium reacts with oxygen gas to produce lithium oxide: a. write a formula for each substance b. Identify reactants and products and write an equation for the reaction. Practice solid lithium = Lioxygen gas = O 2 lithium oxide = Li 2 O Reactants = Li and O 2 Product = Li 2 O 4Li (s) + O 2(g)  2Li 2 O (s)

Read pages , define chemical equation and skeleton equation, AND complete #s 1 and 2 on page Due NOW Assignment

Question of the Day Write a chemical equation: Solid aluminum reacts with oxygen gas to produce solid aluminum oxide (Al 2 O 3 ). Skeleton Equation = Day

Chemical Reactions – Yesterday Bonds … a process in which one or more substances are converted into new substances with different physical and chemical properties

Yesterday Atoms are neither created nor destroyed in ordinary chem. rxns. Conservation of matter -

H 2(g) + F 2(g) 2HF (g) Chemical equation reactantsproducts Yesterday

H 2(g) + F 2(g) 2HF (g) reactantsproducts State of matter: g = gas, l = liquid, s = solid, aq = aqueous solution Yesterday

2H 2(g) + O 2(g) 2H 2 O (l) reactantsproducts Coefficients – how many mols of each element react with each other – mol ratio Yesterday

Balancing Equations Writing a chemical equation: Hydrogen gas reacts with chlorine to produce liquid hydrochloric acid. Hydrogen gas = Chlorine = Liquid Hydrochloric acid =

Balancing Equations Writing a chemical equation: Hydrogen gas reacts with chlorine to produce liquid hydrochloric acid. Reactants = Product = H 2(g) + Cl 2(g)  HCl (l)

Balancing Equations Atoms are neither created nor destroyed in ordinary chem. rxns. - Sum of atoms on each side must be equal - Use coefficients to help

Balancing Equations H 2(g) + Cl 2(g)  HCl (l)

Liquid water breaks apart into hydrogen gas and oxygen gas (electrolysis). Equation: Build:

Solid sodium reacts with chlorine gas to produce solid sodium chloride. Equation: Build:

Review section 11.1 and complete #s (for #s 9 and 11 complete part a only) on page ALL DUE TOMORROW (Thursday 5-12) Assignment

H 2(g) + F 2(g) 2HF (g) ____________________ _______________ Reactions are represented by ___________________ _______________

H 2(g) + F 2(g) 2HF (g) State of matter: g = _______, l = __________, s = _________, aq = _________________________

H 2(g) + F 2(g) 2HF (g) Coefficients – _______________________________ _____________________________________ – mol ratio