Molar Mass - Questions

The Molar Mass Concept Builder is comprised of 42 questions. The questions are organized into 14 different Question Groups and spread across three activities. Questions in the same group are rather similar to one another; they may include the same polyatomic ion or a polyatomic ion with a similar formula. The Concept Builder is coded to select at random a question from each group until a student is successful with that group of questions.

There are three activities that can be engaged in through the Concept Builder. Those three activities are differentiated as follows:
 

• Counting Atoms Activity: Question Groups 1-6 ... Each question provides a formula of a compound containing three or more elements. Students must count the number of atoms of each element in the formula.
• Calculating Molar Mass Activity: Question Groups 7-10 ... Each question provides a formula of a compound containing three or more elements. Students must count the number of atoms of each element, the total mass of the atoms of each element, and the molar mass of the compound.
• Out of This World Activity: Question Groups 11-14 ... This is similar to the previous activity but the elements are fictional elements from the planet Mayedup. The strategy prevents students from being able to complete the activity by using the molar mass calculators that are abundantly available on the web.

The questions from each group are shown below. Teachers are encouraged to view the questions in order to judge which activities are most appropriate for their classes. We recommend providing students two or more options. 

The Physics Classroom grants teachers and other users the right to print these questions for private use. Users are also granted the right to copy the text and modify it for their own use. However, this document should not be uploaded to other servers for distribution to and/or display by others. The Physics Classroom website should remain the only website or server from which the document is distributed or displayed. We also provide a PDF that teachers can use under the same conditions. We have included a link to the PDF near the bottom of this page.

 

Molar Mass

Activity 1: Atom Counting
Question Group 1
Question 1
Counting the number of atoms of each element in a formula is a prerequisite skill to determining the molar mass. Count the number of atoms of each element in the formula ZnCO₃.
 
 
Question 2
Counting the number of atoms of each element in a formula is a prerequisite skill to determining the molar mass. Count the number of atoms of each element in the formula CaCO₃.
 
 
Question 3
Counting the number of atoms of each element in a formula is a prerequisite skill to determining the molar mass. Count the number of atoms of each element in the formula BaCO₃.
 
 
 
Question Group 2
Question 4
Counting the number of atoms of each element in a formula is a prerequisite skill to determining the molar mass. Count the number of atoms of each element in the formula Na₂SO₄.
 
 
Question 5
Counting the number of atoms of each element in a formula is a prerequisite skill to determining the molar mass. Count the number of atoms of each element in the formula K₂SO₄.
 
 
Question 6
Counting the number of atoms of each element in a formula is a prerequisite skill to determining the molar mass. Count the number of atoms of each element in the formula Ag₂SO₄.
 
 
 
Question Group 3
Question 7
Counting the number of atoms of each element in a formula is a prerequisite skill to determining the molar mass. Count the number of atoms of each element in the formula Al₂(SO₄)₃.
 
 
Question 8
Counting the number of atoms of each element in a formula is a prerequisite skill to determining the molar mass. Count the number of atoms of each element in the formula Al₂(CO₃)₃.
 
 
Question 9
Counting the number of atoms of each element in a formula is a prerequisite skill to determining the molar mass. Count the number of atoms of each element in the formula Fe₂(SO₄)₃.
 
 
 
Question Group 4
Question 10
Counting the number of atoms of each element in a formula is a prerequisite skill to determining the molar mass. Count the number of atoms of each element in the formula Ca₃(PO₄)₂.
 
 
Question 11
Counting the number of atoms of each element in a formula is a prerequisite skill to determining the molar mass. Count the number of atoms of each element in the formula Ba₃(PO₄)₂.
 
 
Question 12
Counting the number of atoms of each element in a formula is a prerequisite skill to determining the molar mass. Count the number of atoms of each element in the formula Zn₃(PO₄)₂.
 
 
 
Question Group 5
Question 13
Counting the number of atoms of each element in a formula is a prerequisite skill to determining the molar mass. Count the number of atoms of each element in the formula (NH₄)₂CO₃.
 
 
Question 14
Counting the number of atoms of each element in a formula is a prerequisite skill to determining the molar mass. Count the number of atoms of each element in the formula (NH₄)₂SO₄.
 
 
Question 15
Counting the number of atoms of each element in a formula is a prerequisite skill to determining the molar mass. Count the number of atoms of each element in the formula (NH₄)₂C₂O₄.
 
 
 
Question Group 6
Question 16
Counting the number of atoms of each element in a formula is a prerequisite skill to determining the molar mass. Count the number of atoms of each element in the formula C₂H₅OH.
 
 
Question 17
Counting the number of atoms of each element in a formula is a prerequisite skill to determining the molar mass. Count the number of atoms of each element in the formula C₃H₇OH.
 
 
Question 18
Counting the number of atoms of each element in a formula is a prerequisite skill to determining the molar mass. Count the number of atoms of each element in the formula C₄H₉OH.
 

 
Activity 2: Molar Mass of Compounds
Question Group 7
Question 19
Use the structure of the following table to determine the molar mass of the compound Al₂(SO₄)₃.

 
Question 20
Use the structure of the following table to determine the molar mass of the compound Al₂(CO₃)₃.
 


 
Question 21
Use the structure of the following table to determine the molar mass of the compound Fe₂(C₂O₄)₃.
 

 
 
Question Group 8
Question 22
Use the structure of the following table to determine the molar mass of the compound Ca₃(PO₄)₂.
 

 

 
Question 23
Use the structure of the following table to determine the molar mass of the compound Ba₃(PO₄)₂.
 

 
 
 
 
Question 24
Use the structure of the following table to determine the molar mass of the compound Cu₃(PO₄)₂.
 

 

 
Question Group 9
Question 25
Use the structure of the following table to determine the molar mass of the compound (NH₄)₂SO₄.
 

 
 
Question 26
Use the structure of the following table to determine the molar mass of the compound (NH₄)₂CO₃.
 


 
Question 27
Use the structure of the following table to determine the molar mass of the compound (NH₄)₂SO₃.
 

 
 
Question Group 10
Question 28
Use the structure of the following table to determine the molar mass of the compound Ca(NO₃)₂.
 


 
Question 29
Use the structure of the following table to determine the molar mass of the compound Al(NO₂)₃.
 

 
 
Question 30
Use the structure of the following table to determine the molar mass of the compound Fe(ClO₃)₃.
 

 

 
Activity 3: Out of This World
Question Group 11
Question 31
It's a long story, but ...   Elements are quite different on the planet Mayedup. The symbols, the names, and the atomic mass values are all different than those of planet Earth. The best, most up-to-date, and only existing Periodic Table for elements on planet Mayedup can be found here on this site. Use the table to determine the molar mass of the compound Tp₃(Xo₂Lb₅)₂.
 

 
Question 32
It's a long story, but ...   Elements are quite different on the planet Mayedup. The symbols, the names, and the atomic mass values are all different than those of planet Earth. The best, most up-to-date, and only existing Periodic Table for elements on planet Mayedup can be found here on this site. Use the table to determine the molar mass of the compound Tp₂(Xo₃Lb₄)₃.
 


 
Question 33
It's a long story, but ...   Elements are quite different on the planet Mayedup. The symbols, the names, and the atomic mass values are all different than those of planet Earth. The best, most up-to-date, and only existing Periodic Table for elements on planet Mayedup can be found here on this site. Use the table to determine the molar mass of the compound Tp₄(Xo₅Lb₃)₂.
 

 
 
Question Group 12
Question 34
It's a long story, but ...   Elements are quite different on the planet Mayedup. The symbols, the names, and the atomic mass values are all different than those of planet Earth. The best, most up-to-date, and only existing Periodic Table for elements on planet Mayedup can be found here on this site. Use the table to determine the molar mass of the compound (Ax₂Op₃)₂(XoLb₂)₃.
 

 
Question 35
It's a long story, but ...   Elements are quite different on the planet Mayedup. The symbols, the names, and the atomic mass values are all different than those of planet Earth. The best, most up-to-date, and only existing Periodic Table for elements on planet Mayedup can be found here on this site. Use the table to determine the molar mass of the compound (Ax₃Op)₃(Xo₂Lb₅)₂.
 

 
Question 36
It's a long story, but ...   Elements are quite different on the planet Mayedup. The symbols, the names, and the atomic mass values are all different than those of planet Earth. The best, most up-to-date, and only existing Periodic Table for elements on planet Mayedup can be found here on this site. Use the table to determine the molar mass of the compound (AxOp₃)₄(XoLb₂)₃.
 

 
Question Group 13
Question 37
It's a long story, but ...   Elements are quite different on the planet Mayedup. The symbols, the names, and the atomic mass values are all different than those of planet Earth. The best, most up-to-date, and only existing Periodic Table for elements on planet Mayedup can be found here on this site. Use the table to determine the molar mass of the compound Cp₂(Bz₂Et₅)₃.
 

 
Question 38
It's a long story, but ...   Elements are quite different on the planet Mayedup. The symbols, the names, and the atomic mass values are all different than those of planet Earth. The best, most up-to-date, and only existing Periodic Table for elements on planet Mayedup can be found here on this site. Use the table to determine the molar mass of the compound Cp₃(Bz₃Et₄)₂.
 


 
Question 39
It's a long story, but ...   Elements are quite different on the planet Mayedup. The symbols, the names, and the atomic mass values are all different than those of planet Earth. The best, most up-to-date, and only existing Periodic Table for elements on planet Mayedup can be found here on this site. Use the table to determine the molar mass of the compound Cp₄(Bz₃Et₂)₃.
 

 
Question Group 14
Question 40
It's a long story, but ...   Elements are quite different on the planet Mayedup. The symbols, the names, and the atomic mass values are all different than those of planet Earth. The best, most up-to-date, and only existing Periodic Table for elements on planet Mayedup can be found here on this site. Use the table to determine the molar mass of the compound (Fp₄Gr₃)₃Tr₂.
 


 
Question 41
It's a long story, but ...   Elements are quite different on the planet Mayedup. The symbols, the names, and the atomic mass values are all different than those of planet Earth. The best, most up-to-date, and only existing Periodic Table for elements on planet Mayedup can be found here on this site. Use the table to determine the molar mass of the compound (Fp₃Gr₂)₃Tr₂.
 

 
 
Question 42
It's a long story, but ...   Elements are quite different on the planet Mayedup. The symbols, the names, and the atomic mass values are all different than those of planet Earth. The best, most up-to-date, and only existing Periodic Table for elements on planet Mayedup can be found here on this site. Use the table to determine the molar mass of the compound (Fp₃Gr₂)₂Tr₅.