The Weight expression

The Weight Expression (expressionOchemEvalWeight) compares the molecular weight of the student’s response to an author coded value.

• The Weight expression is available for items created with the solutionOchemSkeletal answer type.
• How to add one or more expressions
• How to specify the Grade and Response information
• Use the dropdown menus and text boxes to set or edit the molecular weight you want to be evaluated in student responses.

• Molecular weights used in Mastering: See the section below or from MarvinSketch, choose View > Periodic System. Authors should use these molecular weights when calculating the expression.

The author-coded value is a real number with a range (plus or minus a real number) to account for variations in significant figures and changes in the scientific precision of molecular weights. The author must specify the range; there is no default range.

 

See also:

Expressions overview (Ochem answer types)

Working with Ochem expressions