ChemicalReaction1

From WeBWorK_wiki
Revision as of 05:22, 18 July 2023 by Pstaabp (talk | contribs) (add historical tag and give links to newer problems.)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to navigation Jump to search
This article has been retained as a historical document. It is not up-to-date and the formatting may be lacking. Use the information herein with caution.

This problem has been replaced with a newer version of this problem

Chemical Reactions

Click to enlarge

This PG code shows how ask questions about chemical reactions.


Templates by Subject Area

PG problem file Explanation

Problem tagging data

Problem tagging: 

DOCUMENT();

loadMacros(
"PGstandard.pl",
"PGunion.pl",
"MathObjects.pl",
"PGML.pl",
"contextReaction.pl",
"PGcourse.pl",
);

TEXT(beginproblem()); # uncomment
$showPartialCorrectAnswers = 1;

Initialization: Load contextReaction.pl. 

Context("Reaction");

@reactants = ();
@products = ();
	
$reactants[0] = Formula("2C_2H_6 + 7O_2");
$products[0]  = Formula("4CO_2 + 6H_2O");

$reactants[1] = Formula("6CO_2 + 6O_2");
$products[1] = Formula("C_6 H_12 O_6 + 6 O_2");

$reactants[2] = Formula("3 Ca Cl_2 + 2 Na_3 PO_4");
$products[2] = Formula("Ca_3 (PO_4)_2 + 6 Na Cl");

# variations on 2NaOH + MgCl_2 --> 2NaCl + Mg(OH)_2
$a = list_random('Li','Na','K');
$b = list_random('F','Cl','Br');

# Use ${b}_2 instead of $b_2 below so that Perl knows the 
# variable name is $b = ${b} and not $b_2 = ${b_2}.
$reactants[3] = Formula("2 $a OH + Mg ${b}_2"); 
$products[3] = Formula("2 $a $b + Mg (OH)_2");

$num_choices = $#reactants;

$i = random(0,$num_choices,1);

Setup: We create a couple of arrays @reactants and @products and fill them with some examples of balanced chemical equations. The second and third examples show that groupings, such as for (OH)_2 are necessary. The third example shows how you could randomize a chemical reaction question. In particular, note that ${b}_2 is needed instead of $b_2 so that Perl interprets the variable as $b with a subscript of 2 instead of a variable named $b_2 with no subscript. 

BEGIN_PGML
[` [$reactants[ $i ]] \longrightarrow `] [_____________________________]{$products[ $i ]}

Enter a subscript using an underscore, such as [| H_2 O |]* for [` \mathrm{H_2 O} `].
END_PGML

COMMENT('MathObject version.  Uses PGML.');
ENDDOCUMENT();

Main Text: Note that we uses spaces around $i in things like $reactants[ $i ] and $products[ $i ]. This is a work around for a known PGML bug as of June 2015 (the bug will likely get fixed very soon).

Templates by Subject Area

Retrieved from "https://webwork.maa.org/mediawiki_new/index.php?title=ChemicalReaction1&oldid=23785"