E.WhiteLaw of Conservation of Mass- Week 6 9/15/25-9/19/25

Monday
9/22/25
Counting Atoms & Law of Conservation

Math Response

A chemical equation for the reaction between calcium hydroxide Ca(OH)_2, and sulfuric acid, H₂SO₄, is shown. The masses of some of the reactants and products are given in grams.

According to the Law of Conservation of Mass, how many grams of sulfuric acid were used in this reaction?

Type answer here

Correct Answer: 98

Deg^°

Rad

Multiple Choice

Calculate the number of Oxygen atoms in Al(OH)₃

• 1

• 2

• 3

• 4

Multiple Choice

Coefficients in chemical formulas...

• Multiply just the first atom

• Add to the subscripts at the end of the molecule

• Multiply elements without subscripts

• Multiply EVERYTHING!

Multiple Choice

C₃H₅(NO₃)₃

• C = 3, H = 5, N = 3, O = 9

• C = 3, H = 5, N = 1, O = 9

• C = 9, H = 15, N = 3, O = 9

• C = 9, H = 15, N = 1, O = 3

Multiple Choice

A subscript is the small number below a(n) ________ that tells the number of _______ of that element.

• element symbol; atoms
• atom; element symbol
• subscript; protons
• compound; elements

Multiple Choice

A ______ is a number written in front of a chemical formula.

• Coefficient

• Subscript

• Exponent

• Coordinator

Match

Match the element to the number of atoms it has.

2 Al(C₂H₃O₄)₂

• aluminum

• carbon

• hydrogen

• oxygen

2

8

12

16

• 2

• 8

• 12

• 16

Place on page 32

Go ahead and fill in the getting started, make a prediction about what happens to the atoms in the log (hint* you should know)

​place on page 33

Open Ended

Labeling

Label the reactants and products of the chemical reaction shown.

Drag labels to their correct position on the image

Reactants

Products

Dropdown

Examine the experiment shown, then fill in the blanks.

The experiment shows a ​

Select answer

system.

The mass at the end of the experiment will be ​

Select answer

the initial mass.

Drag and Drop

Two solutions are mixed and react to produce the solid precipitate AgCl. The chemical reaction is shown below. According to the Law of Conservation of Mass, what happens to the TOTAL mass as the reaction takes place?



The mass will ​

Placeholder

.

Drag these tiles and drop them in the correct blank above

remain constant

increase

decrease

first decrease and then increase

Categorize

Options (5)

Na₂CO₃

NaCl

H₂O

HCl

CO₂

For this reaction equation, sort the substances into reactants or products.

$$Na_2CO_3\left(s\right)+HCl\left(aq\right)\rightarrow NaCl\left(aq\right)+H_2O\left(l\right)+CO_2\left(g\right)$$

Reactants

Products

Multiple Choice

The reactants in the image above are:

• CH4 and 2 O2

• 2 H2O and CO2

• All of these are reactants

• All of these are products

Fill in the Blanks

Potassium hydroxide, KOH, reacts with hydrochloric acid, HCl, to form a salt and water. What mass of hydrochloric acid, to the nearest hundredth of a gram, is required for this chemical reaction?

Multiple Choice

According to the law of conservation of mass, how much zinc was present in the zinc carbonate?

• 256 g

• 88 g

• 104 g

• 40 g

Open Ended

Explain the law of conservation of mass is your own words.

Multiple Choice

• A

• B

• C

• D

Multiple Choice

• A

  62g

• B

  98g

• C

  36g

• D

  100

  g

Multiple Choice

Anthony is performing an experiment. He adds 0.25 grams of baking soda to 5 grams of water and stirs. Anthony watches as the baking soda dissolves in the water. If Anthony weighs the water and baking soda solution, what will its mass be?

• 4.75 grams

• 5.25 grams

• 5.0 grams

• 7.5 grams

Poll

How confident do you feel about this topic now?

• Very confident
• Somewhat confident
• Not confident