Combustion Lab Results

The students analyze data from the rocket combustion lab started in the previous segment and hear from special guest Dr. David Gottfried about nanotechnology.

The students perform a rocket combustion lab in this segment.

Analyzing and Interpreting Data

Once collected, data must be presented in a form that can reveal any patterns and relationships and that allows results to be communicated to others. Because raw data as such have little meaning, a major practice of scientists is to organize and interpret data through tabulating, graphing, or statistical analysis. Such analysis can bring out the meaning of data—and their relevance—so that they may be used as evidence.

Engineers, too, make decisions based on evidence that a given design will work; they rarely rely on trial and error. Engineers often analyze a design by creating a model or prototype and collecting extensive data on how it performs, including under extreme conditions. Analysis of this kind of data not only informs design decisions and enables the prediction or assessment of performance but also helps define or clarify problems, determine economic feasibility, evaluate alternatives, and investigate failures. (NRC Framework, 2012, p. 61-62)

Engaging in Argument from Evidence

The study of science and engineering should produce a sense of the process of argument necessary for advancing and defending a new idea or an explanation of a phenomenon and the norms for conducting such arguments. In that spirit, students should argue for the explanations they construct, defend their interpretations of the associated data, and advocate for the designs they propose. (NRC Framework, 2012, p. 73)

Generating a Hypothesis and Developing a Model

Modeling can begin in the earliest grades, with students’ models progressing from concrete “pictures” and/or physical scale models (e.g., a toy car) to more abstract representations of relevant relationships in later grades, such as a diagram representing forces on a particular object in a system. (NRC Framework, 2012, p. 58)

Using Mathematics and Computational Thinking

Although there are differences in how mathematics and computational thinking are applied in science and in engineering, mathematics often brings these two fields together by enabling engineers to apply the mathematical form of scientific theories and by enabling scientists to use powerful information technologies designed by engineers. Both kinds of professionals can thereby accomplish investigations and analyses and build complex models, which might otherwise be out of the question. (NRC Framework, 2012, p. 65)

** atomic mass unit **- equals 1/12 the mass of a carbon atom.

**Avagadro's number** - the number of atoms in a mole, equal to 6.02x10^23 atoms.

**conversion factor **- a ratio expressed as a fraction that equals one.

**dimensional analysis** - the sequential application of conversion factors expressed as fractions and arranged so that any dimensional unit can be cancelled out until the desired set of dimensional units is obtained.

**empirical formula** - the simplest formula of a compound expressed as the smallest possible ratio of the elements.

**equivalence statement **- a statement that shows the quantities and units that are equal to each other.

**excess reactant** - the reactant in a chemical reaction that remains when a reaction stops once the limiting reactant is completely consumed.

**limiting reactant **- the reactant in a chemical reaction that limits the amount of product formed.

**molar mass **- the mass, in grams, of a mole of a substance.

**molar volume** - the volume of one mole of any gas at standard temperature and pressure.

**mole** - The SI unit that measures the amount of matter a substance has; one mole is equal to 6.022x10^23 representative particles, also known as Avagadro's number.

**mole ratio **- the ratio of moles of one substance to the moles of another substance in a balanced equation.

**molecular formula** - a formula which states the exact number and type of each atom present in a molecule of a substance.

**percent composition** - the percentage by mass of each element in a compound.

**percent yield **- the ratio of the actual yield to the theoretical yield of a material.

**stoichiometry **- the calculation of the quantities of reactants and products involved in a chemical reaction.

**theoretical yield** - the amount of product formed from the complete conversion of a limiting reactant in a chemical reaction.

**SC3**Obtain, evaluate, and communicate information about how the Law of Conservation of Matter is used to determine chemical composition in compounds and chemical reactions.

**SC3.a**Use mathematics and computational thinking to balance chemical reactions (i.e. synthesis, decomposition, single replacement, double replacement, and combustion) and construct an explanation for the outcome of a simple chemical reaction based on the outermost electron states of atoms, trends in the periodic table, and knowledge of the patterns of chemical properties.

**SC3.b**Plan and carry out investigations to determine that a new chemical has formed by identifying indicators of a chemical reaction (specifically precipitate formation, gas evolution, color change, water production, and changes in energy to the system should be investigated).

**SC3.c**Use mathematics and computational thinking to apply concepts of the mole and Avogadro’s number to conceptualize and calculate:

• percent composition

• empirical/molecular formulas

• mass, moles, and molecules relationships

• molar volumes of gases

(Clarification statement for elements c and d: Emphasis is on use of mole ratios to compare quantities of reactants or products and on assessing students’ use of mathematical thinking and is not on memorization and rote application of problem- solving techniques.)

**SC3.d**Use mathematics and computational thinking to identify and solve different types of reaction stoichiometry problems (i.e., mass to moles, mass to mass, moles to moles, and percent yield) using significant figures. (Clarification statement for elements c and d: Emphasis is on use of mole ratios to compare quantities of reactants or products and on assessing students’ use of mathematical thinking and is not on memorization and rote application of problem- solving techniques.)

**SC3.e**Plan and carry out an investigation to demonstrate the conceptual principle of limiting reactants.

The Chemistry Matters teacher toolkit provides instructions and answer keys for labs, experiments, and assignments for all 12 units of study. GPB offers the teacher toolkit at no cost to Georgia educators. Complete and submit this form to request the teacher toolkit. *You only need to submit this form one time to get materials for all 12 units of study.*