chemical reactions

Chemistry Assessment

Eligible Texas EssentialKnowledge and Skills

Texas Education AgencyStudent Assessment DivisionSeptember 2010

Readiness standards have the following characteristics.

•They are essential for success in the current grade or course.

•They are important for preparedness for the next grade or course.

•They support college and career readiness.

•They necessitate in-depth instruction.

•They address broad and deep ideas.


Supporting standards have the following characteristics.

• Although introduced in the current grade or course, they may be emphasized in a subsequent year.

• Although reinforced in the current grade or course, they may be emphasized in a previous year.

• They play a role in preparing students for the next grade or course but not a central role.

• They address more narrowly defined ideas.


TEA is implementing a number of changes that should serve to test knowledge and skills in a deeper way.

• Tests will contain a greater number of items that have a higher cognitive complexity level.

• Items will be developed to more closely match the cognitive complexity level evident in the TEKS.

• In science, process skills will be assessed in context, not in isolation, which will allow for a more integrated and authentic assessment of these content area.

• In science, the number of open-ended (griddable) items will increase to allow students more opportunity to derive an answer independently.


Engage

Whoosh bottle

Gummi bear

Burning bubbles

Sodium in H2O

Prior knowledge?

• Write chemical formulas

• Atomic masses

• What is a precipitate

What should be taught?

• Write equations given formulas or names• Balance equations by counting atoms• Types of reactions • Predict products• Activity series • Solubility rules and net ionic equations• Oxidation and reduction

Assign oxidation numbers; ID agents• Simple equilibrium using LeChatelier’s principle• Factors affecting rates of reactions

What will constitute mastery?

The student should be able to:

• Write, balance and predict equations for all 5 general types of reactions

• Write net ionic equations

• Use activity series

Calcium hydroxide reacts with ammonium sulfate.The balanced equation for this reaction is

a) CaOH2 + NH4SO4 CaSO4 + NH4OH

b) Ca(OH)2 + (NH4)2SO4 CaSO4 + 2 NH4OH

c) Ca(OH)2 + (NH4)2SO4 CaSO4 + NH4OH

d) Ca(OH)2 + (NH4)2SO4 CaSO4 + 2 NH3 + H2O

Do they really need to know this?

Which reaction shows a balanced net ionic equation for the reaction between silver nitrate and potassium iodide?

a) AgNO3 + KI AgI + KNO3

b) Ag+ + I- AgI

c) K+ + NO3- + KNO3

d) 2 AgNO3 + 2 KI 2 AgI + 2 KNO3

Net Ionic

CCRS

CH4 + 2 O2 CO2 + 2 H2O

In this equation, what substance is being oxidized?

a) CH4

b) O2

c) CO2

d) H2O

Or

Identify the oxidizing agent.

Oxidation/reduction

Which of these reactions will occur?

a) Pb + ZnCl2

b) Mg + FeCl3

c) Zn + MgCl2

d) Cu + NaCl

Activity series

CCRS

Carbon burns faster in pure oxygen than in air because…..

a) Higher concentration of reactant

b) Oxygen is a catalyst

c) The temperature is increased

d) The oxygen is a gas

Factors that affect reaction rates

In which direction will the equilibrium shift for this reaction if the temperature is increased?

CH4 + 2 O2 CO2 + 2 H2O + energy

a) Left because it is exothermic

b) Left because it is endothermic

c) Right because it is exothermic

d) Right because it is endothermic

Or

SO2 + O2 ↔ 2 SO3 ∆H = -197.9 kJ/mol

CCRS

Pre-AP