# Forming A Precipitate

Students will combine two clear colorless solutions (baking soda solution and calcium chloride solution) and see the formation of a solid and a gas. Students will analyze the chemical equation for the reaction and see that all atoms in the reactants end up in the products. They will make the connection between the chemical equation and the real substances and see that the solid and gas produced in the actual reaction are also in the products of the equation.

### Standards & Objectives

CCSS.Math.Content.3.G.A.2
Partition shapes into parts with equal areas. Express the area of each part as a unit fraction of the whole. For example, partition a shape into 4...
CCSS.Math.Content.3.NF.A.1
Understand a fraction 1/b as the quantity formed by 1 part when a whole is partitioned into b equal parts; understand a fraction a/b as the...
CCSS.Math.Content.3.NF.A.2
Understand a fraction as a number on the number line; represent fractions on a number line diagram.
CCSS.Math.Content.3.NF.A.3
Explain equivalence of fractions in special cases, and compare fractions by reasoning about their size.
CCSS.Math.Content.4.MD.A.2
Use the four operations to solve word problems involving distances, intervals of time, liquid volumes, masses of objects, and money, including...
CCSS.Math.Content.4.MD.B.4
Make a line plot to display a data set of measurements in fractions of a unit (1/2, 1/4, 1/8). Solve problems involving addition and subtraction of...
CCSS.Math.Content.4.NBT.A.2
Read and write multi-digit whole numbers using base-ten numerals, number names, and expanded form. Compare two multi-digit numbers based on...
CCSS.Math.Content.4.NF.A.1
Explain why a fraction a/b is equivalent to a fraction (n x a)/(n x b) by using visual fraction models, with attention to how the number and size...
CCSS.Math.Content.4.NF.A.2
Compare two fractions with different numerators and different denominators, e.g., by creating common denominators or numerators, or by comparing to...
CCSS.Math.Content.4.NF.B.3
Understand a fraction a/b with a > 1 as a sum of fractions 1/b.
CCSS.Math.Content.4.NF.B.4
Apply and extend previous understandings of multiplication to multiply a fraction by a whole number.
CCSS.Math.Content.4.NF.C.5
Express a fraction with denominator 10 as an equivalent fraction with denominator 100, and use this technique to add two fractions with respective...
CCSS.Math.Content.4.NF.C.6
Use decimal notation for fractions with denominators 10 or 100. For example, rewrite 0.62 as 62/100; describe a length as 0.62 meters; locate 0.62...
CCSS.Math.Content.4.NF.C.7
Compare two decimals to hundredths by reasoning about their size. Recognize that comparisons are valid only when the two decimals refer to the same...
CCSS.Math.Content.4.OA.A.2
Multiply or divide to solve word problems involving multiplicative comparison, e.g., by using drawings and equations with a symbol for the unknown...
CCSS.Math.Content.4.OA.A.3
Solve multistep word problems posed with whole numbers and having whole-number answers using the four operations, including problems in which...
CCSS.Math.Content.5.MD.B.2
Make a line plot to display a data set of measurements in fractions of a unit (1/2, 1/4, 1/8). Use operations on fractions for this grade to solve...
CCSS.Math.Content.5.NBT.B.5
Fluently multiply multi-digit whole numbers using the standard algorithm.
CCSS.Math.Content.5.NF.A.1
Add and subtract fractions with unlike denominators (including mixed numbers) by replacing given fractions with equivalent fractions in such a way...
CCSS.Math.Content.5.NF.A.2
Solve word problems involving addition and subtraction of fractions referring to the same whole, including cases of unlike denominators, e.g., by...
CCSS.Math.Content.5.NF.B.3
Interpret a fraction as division of the numerator by the denominator (a/b = a / b). Solve word problems involving division of whole numbers leading...
CCSS.Math.Content.5.NF.B.4
Apply and extend previous understandings of multiplication to multiply a fraction or whole number by a fraction.
CCSS.Math.Content.5.NF.B.7
Apply and extend previous understandings of division to divide unit fractions by whole numbers and whole numbers by unit fractions.1
CCSS.Math.Content.6.RP.A.3
Use ratio and rate reasoning to solve real-world and mathematical problems, e.g., by reasoning about tables of equivalent ratios, tape diagrams,...
GLE 0306.2.4
Solve multiplication and division problems using various representations.
GLE 0306.2.5
Understand the meaning and uses of fractions.
GLE 0306.2.6
Use various strategies and models to compare and order fractions and identify equivalent fractions.
GLE 0306.2.7
Add and subtract fractions with like denominators using various models.
GLE 0406.1.2
Apply and adapt a variety of appropriate strategies to problem solving, including estimation, and reasonableness of the solution.
GLE 0406.2.2
Develop fluency with multiplication and single-digit division.
GLE 0406.2.4
Understand and use the connections between fractions and decimals.
GLE 0406.2.5
Add and subtract fractions with like and unlike denominators.
GLE 0406.2.6
Solve problems involving whole numbers, fractions, and/or decimals using all four arithmetic operations.
GLE 0406.3.1
Extend understanding of a variable to equations involving whole numbers, fractions, decimals, and/or mixed numbers.
GLE 0406.3.3
Translate between different forms of representations of whole number relationships.
GLE 0406.4.2
Understand and use measures of length, area, capacity, and weight.
GLE 0406.4.3
Solve problems that involve estimating and measuring length, area, capacity and weight.
GLE 0406.5.1
Collect, record, arrange, present, and interpret data using tables and various representations.
GLE 0506.2.4
Develop fluency with addition and subtraction of proper and improper fractions and mixed numbers; explain and model the algorithm.
GLE 0506.5.1
Make, record, display and interpret data and graphs that include whole numbers, decimals, and fractions.
GLE 0606.2.3
Understand and use ratios, rates and percents.
GLE 0606.3.6
Understand and use the Cartesian coordinate system.
GLE 0706.4.2
Apply proportionality to converting among different units of measurements to solve problems involving rates such as motion at a constant speed.
GLE 0706.4.4
Understand and use ratios, derived quantities, and indirect measurements.
GLE 0807.9.8
Interpret the events represented by a chemical equation.
SPI 0306.1.2
Solve problems involving elapsed time.
SPI 0306.1.4
Match the spoken, written, concrete, and pictorial representations of fractions with denominators up to ten.
SPI 0306.2.10
Identify equivalent fractions given by various representations.
SPI 0306.2.11
Recognize and use different interpretations of fractions.
SPI 0306.2.12
Name fractions in various contexts that are less than, equal to, or greater than one.
SPI 0306.2.13
Recognize, compare, and order fractions (benchmark fractions, common numerators, or common denominators).
SPI 0306.2.14
Add and subtract fractions with like denominators.
SPI 0406.1.2
Compare decimals using concrete and pictorial representations.
SPI 0406.2.1
Read and write numbers from hundredths to hundred-thousands in numerals and in words.
SPI 0406.2.10
Solve contextual problems using whole numbers, fractions, and decimals.
SPI 0406.2.11
Solve problems using whole number multi-digit multiplication.
SPI 0406.2.3
Identify the place value of a specified digit in a number and the quantity it represents.
SPI 0406.2.5
Generate equivalent forms of common fractions and decimals and use them to compare size.
SPI 0406.2.6
Use the symbols and = to compare common fractions and decimals in both increasing and decreasing order.
SPI 0406.2.8
Add and subtract proper fractions with like and unlike denominators and simplify the answer.
SPI 0406.3.1
Use letters and symbols to represent an unknown quantity and write a simple mathematical expression
SPI 0406.4.7
Determine appropriate size of unit of measurement in problem situations involving length, capacity or weight.
SPI 0406.5.1
Depict data using various representations (e.g., tables, pictographs, line graphs, bar graphs).
SPI 0406.5.2
Solve problems using estimation and comparison within a single set of data.
SPI 0506.1.2
Estimate fraction and decimal sums or differences.
SPI 0506.2.7
Recognize equivalent representations for the same number.
SPI 0606.2.1
Solve problems involving the multiplication and division of fractions.
SPI 0606.2.6
Solve problems involving ratios, rates and percents.
SPI 0606.3.9
Graph ordered pairs of integers in all four quadrants of the Cartesian coordinate system.
SPI 0706.2.6
Express the ratio between two quantities as a percent, and a percent as a ratio or fraction.
SPI 0806.1.1
Solve problems involving rate/time/distance (i.e., d = rt).
SPI 0806.1.3
Calculates rates involving cost per unit to determine the best buy.
SPI 0806.4.4
Convert between and within the U.S. Customary System and the metric system.
TSS.Math.3.G.A.2
Partition shapes into parts with equal areas. Express the area of each part as a unit fraction of the whole.
TSS.Math.3.NF.A.1
Understand a fraction, 1/b, as the quantity formed by 1 part when a whole is partitioned into b equal parts (unit fraction); understand a fraction a/b as...
TSS.Math.3.NF.A.2
Understand a fraction as a number on the number line. Represent fractions on a number line.
TSS.Math.3.NF.A.3
Explain equivalence of fractions and compare fractions by reasoning about their size.
TSS.Math.4.MD.A.2
Solve one- or two-step real-world problems involving whole number measurements with all four operations within a single system of measurement including...
TSS.Math.4.MD.B.4
Make a line plot to display a data set of measurements in fractions of a unit (1/2, 1/4, 1/8). Use operations on fractions for this grade to solve problems...
TSS.Math.4.NBT.A.2
Read and write multi-digit whole numbers (less than or equal to 1,000,000) using standard form, word form, and expanded form (e.g. the expanded form of...
TSS.Math.4.NF.A.1
Explain why a fraction a/b is equivalent to a fraction (axn)/(bxn) or (a/n)/(b/n) by using visual fraction models, with attention to how the number and size...
TSS.Math.4.NF.A.2
Compare two fractions with different numerators and different denominators by creating common denominators or common numerators or by comparing to a...
TSS.Math.4.NF.B.3
Understand a fraction a/b with a > 1 as a sum of fractions 1/b. For example, 4/5 = 1/5 + 1/5 + 1/5 + 1/5.
TSS.Math.4.NF.B.4
Apply and extend previous understandings of multiplication as repeated addition to multiply a whole number by a fraction.
TSS.Math.4.NF.C.5
Express a fraction with denominator 10 as an equivalent fraction with denominator 100, and use this technique to add two fractions with respective...
TSS.Math.4.NF.C.6
Read and write decimal notation for fractions with denominators 10 or 100. Locate these decimals on a number line.
TSS.Math.4.NF.C.7
Compare two decimals to hundredths by reasoning about their size. Recognize that comparisons are valid only when the two decimals refer to the same whole....
TSS.Math.4.OA.A.2
Multiply or divide to solve contextual problems involving multiplicative comparison, and distinguish multiplicative comparison from additive comparison.
TSS.Math.4.OA.A.3
Solve multi-step contextual problems posed with whole numbers and having whole-number answers using the four operations, including problems in which...
TSS.Math.5.MD.B.2
Make a line plot to display a data set of measurements in fractions of a unit (1/2, 1/4, 1/8). Use operations on fractions for this grade to solve problems...
TSS.Math.5.NBT.B.5
Fluently multiply multi-digit whole numbers (up to three-digit by four-digit factors) using appropriate strategies and algorithms.
TSS.Math.5.NF.A.1
Add and subtract fractions with unlike denominators (including mixed numbers) by replacing given fractions with equivalent fractions in such a way as to...
TSS.Math.5.NF.A.2
Solve contextual problems involving addition and subtraction of fractions referring to the same whole, including cases of unlike denominators. Use benchmark...
TSS.Math.5.NF.B.3
Interpret a fraction as division of the numerator by the denominator (a/b = a ÷ b). For example, 3/4 = 3 ÷ 4 so when 3 wholes are shared equally...
TSS.Math.5.NF.B.4
Apply and extend previous understandings of multiplication to multiply a fraction by a whole number or a fraction by a fraction.
TSS.Math.5.NF.B.7
Apply and extend previous understandings of division to divide unit fractions by whole numbers and whole numbers by unit fractions.
TSS.Math.6.RP.A.3
Use ratio and rate reasoning to solve real-world and mathematical problems.

Alignment of this item to academic standards is based on recommendations from content creators, resource curators, and visitors to this website. It is the responsibility of each educator to verify that the materials are appropriate for your content area, aligned to current academic standards, and will be beneficial to your specific students.

Learning objectives:

Students will be able to explain that for a chemical reaction to take place, the reactants interact, bonds between certain atoms in the reactants are broken, the atoms rearrange, and new bonds between the atoms are formed to make the products. Students will also be able to explain that this definition applies to the production of a solid called a precipitate.

Essential and guiding questions:

Would you consider adding a sodium carbonate solution to a magnesium sulfate solution a chemical reaction?  Why or Why not?

How do you know when a precipitate is formed in a chemical reaction?

What did you observe when you mixed the baking soda solution and the calcium chloride solution?

Did you observe a precipitate?

Do you think this was a chemical reaction?  Why?

What products of the reaction do you recognize?

Look at the product side of the chemical equation. What gas is produced in the chemical reaction?

What do you think is the precipitate?

How many of each type of atom is on the reactant side of the equation?

How many of each type of atom is on the product side of the chemical equation?

Is this a balanced chemical equation?  Why?

How do you think we could separate the precipitate from the other products?

Can you separate the calcium carbonate from the rest of the products?

What is the solid white substance on the paper?

Is filtering out the calcium carbonate and allowing the water to evaporate a chemical change or a physical change?  Why?

What evidence was there that a chemical reaction occurred when you combined baking soda solution and calcium chloride solution?

How could we compare the precipitate to the reactants to be sure that the precipitate is actually different from both of them?

Is the solubility of the precipitate different than the solubility of baking soda and calcium chloride?

How should we set up the solubility test?

Should we use the same amount of each substance?

Should we use the same amount of water?

### Lesson Variations

Blooms taxonomy level:
Understanding
Extension suggestions:

Do a demonstration to show students another example of a precipitate and a color change.

Materials for the Demonstrations:

• Sodium carbonate
• Epsom salt (magnesium sulfate)
• 2 clear plastic cups
• Test tube
• Water
• Copper II sulfate
• Household ammonia
• Hydrogen peroxide (3%)
• 2 droppers

Materials for Each Group

• Baking soda
• Calcium chloride
• Water