Author a chemical equation sub-type
This sub-type is authored by selecting the Chemical Equation option from the Sub-type drop-down list during mathematical formula question authoring.
Examples of accepted syntax for defining the Answer field value for this sub-type are:
H_2SO_4
- 2H_2+O_2 -> 2H_2O
The chemical equation sub-type Answer field:
- Uses only the following 2D text entry characters (which are interpreted by Möbius into symbolic chemistry):
| Type of symbol | Keyboard character | Example of text entry | Example of symbolic interpretation by Möbius |
|---|---|---|---|
| Superscripts | ^ | Ca^2 (aq) |  |
| Subscripts | _ (underscore) | H_2SO_4 |  |
| Arrows | -> or <- or <=> | 2H_2+O_2 -> 2H_2O |  |
| Dot operator | * | CuSO_4*5H_2O |  |
| Addition | + | 2H_2+O_2 |  |
| Polarity and ion charges | + or - (combined with ^) | CO_3^2- (aq) |  |
TIP: You can use the Equation Editor's chemistry palette to author your question statement using chemistry symbols instead of 2D text. Check out Work with the Equation Editor (instructor).
Accepts physical states in parentheses if required by your equation (Example — Ca^2 (aq)).
Accepts parentheses to clarify the interpretation of groups of characters if required by your equation (Example — (CO_3)^2- (aq)).
Ignores spaces within your equation.
Doesn't accept equivalent responses as student responses must be an exact match to the defined correct answer.
TIP: Be sure to author instructions for your students to inform them of the expected order of the reactants or products (Example — alphabetical order of elements) and if physical states are required.
NOTE: This question sub-type allows the student to choose whether they want to submit their response using Symbol Mode (using the Equation Editor) or Text Mode (as a single line using their keyboard).
NOTE: The chemical equation question is one of the ten sub-types of the mathematical formula question. Check out Choose a mathematical formula question sub-type for an explanation of each of the ten available mathematical formula question sub-types.
TIP: Check out Author a mathematical formula question for full question authoring instructions.
Example of this sub-type
- Question statement:
Enter the reaction of hydrochloric acid (HCl) with sodium hydroxide (NaOH).
For the purpose of correct grading, please write the reactants and products in alphabetical order of elements on either side of the equation.
- Answer field syntax:
HCl + NaOH -> H_2O + NaCl
Example of this sub-type with an algorithm
- Question statement:
Write a balanced equation for the complete combustion of $gas gas.
For the purpose of correct grading, please write the reactants and products in alphabetical order on either side of the equation. Include physical states.
The complete and balanced reaction is:
- Algorithm:
$i=rint(2);
$gas=switch($i,"propane","methane");
$formula=switch($i,"C_3H_8(g)+5O_2(g)->3CO_2(g)+4H_2O(l)","CH_4(g)+2O_2(g)->CO_2(g)+2H_2O(l)");
- Answer field syntax:
$formula
NOTE: The dollar sign ($) character can only be used in mathematical formula questions when it's a part of a variable name. Be sure to define algorithmic variables in the Algorithm pane in order to use them in the Answer field.
