// Numbas version: exam_results_page_options {"name": "Rearranging concentration formula for mass (numeric)", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "question_groups": [{"pickingStrategy": "all-ordered", "questions": [{"functions": {}, "ungrouped_variables": ["chem"], "name": "Rearranging concentration formula for mass (numeric)", "tags": ["concentration", "ephlth", "nursing"], "preamble": {"css": "", "js": ""}, "advice": "", "rulesets": {}, "parts": [{"stepsPenalty": "1", "prompt": "

A solution has a percentage concentration of {ansb} % w/v of {chem}. It was made by mixing {millb} mL of solvent and  [[0]] grams of {chem}.

", "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "gaps": [{"allowFractions": false, "variableReplacements": [], "maxValue": "gramsb", "minValue": "gramsb", "variableReplacementStrategy": "originalfirst", "correctAnswerFraction": false, "showCorrectAnswer": true, "scripts": {}, "marks": 1, "type": "numberentry", "showPrecisionHint": false}], "steps": [{"prompt": "

Given \\[\\text{percentage concentration (w/v)}=\\dfrac{\\text{mass of solute (g)}}{\\text{volume of solvent (mL)}}\\times \\text{100},\\]

\n

we can substitute our values for percentage concentration and volume of solvent and rearrange to get the value of 'mass of solute (g)'. 

\n

\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
$\\text{percentage concentration (w/v)}$$=$$\\dfrac{\\text{mass of solute (g)}}{\\text{volume of solvent (mL)}}\\times \\text{100}$
 
$\\var{ansb}  \\text{ % (w/v)}$$=$$\\dfrac{\\text{mass of solute (g)}}{\\var{millb} \\text{ mL}}\\times 100$
 
$\\dfrac{\\var{ansb}  \\text{ % (w/v)}}{100}$$=$$\\dfrac{\\text{mass of solute (g)}}{\\var{millb} \\text{ mL}}\\times \\dfrac{100}{100}$
 
$\\dfrac{\\var{ansb}  \\text{ % (w/v)}}{100}$$=$$\\dfrac{\\text{mass of solute (g)}}{\\var{millb} \\text{ mL}}$
 
$\\dfrac{\\var{ansb}  \\text{ % (w/v)}}{100}\\times \\var{millb} \\text{ (mL)}$$=$$\\dfrac{\\text{mass of solute (g)}}{\\var{millb} \\text{ mL}}\\times \\var{millb} \\text{ mL}$
 
$\\var{gramsb} \\text{ (g)}$$=$$\\text{mass of solute (g)}$
", "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "showCorrectAnswer": true, "scripts": {}, "marks": 0, "type": "information"}], "scripts": {}, "marks": 0, "showCorrectAnswer": true, "type": "gapfill"}], "statement": "", "variable_groups": [{"variables": [], "name": "b"}, {"variables": ["ansb", "millb", "gramsb", "k"], "name": "whole numbers that result in simple decimal"}], "variablesTest": {"maxRuns": 100, "condition": ""}, "variables": {"k": {"definition": "random(2..12)", "templateType": "anything", "group": "whole numbers that result in simple decimal", "name": "k", "description": ""}, "chem": {"definition": "random([\"$\\\\text{NaCl}$\",\"$\\\\text{KCl}$\",\"$\\\\mathrm{C_3H_5NaO_3}$\",\"$\\\\mathrm{CaCl_2.2H_2O}$\",\"$\\\\mathrm{Ca_3PO_4}$\",\"$\\\\mathrm{MgCl_2}$\",\"$\\\\mathrm{Na_2HPO_4}$\",\"$\\\\mathrm{Na_2SO_4}$\"])", "templateType": "anything", "group": "Ungrouped variables", "name": "chem", "description": ""}, "gramsb": {"definition": "ansb*2*k", "templateType": "anything", "group": "whole numbers that result in simple decimal", "name": "gramsb", "description": ""}, "ansb": {"definition": "random(0.5..10.5#1)", "templateType": "anything", "group": "whole numbers that result in simple decimal", "name": "ansb", "description": ""}, "millb": {"definition": "100*2*k", "templateType": "anything", "group": "whole numbers that result in simple decimal", "name": "millb", "description": ""}}, "metadata": {"notes": "

https://en.wikipedia.org/wiki/Mass_concentration_(chemistry)#Usage_in_biology

", "description": "", "licence": "Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International"}, "type": "question", "showQuestionGroupNames": false, "question_groups": [{"name": "", "pickingStrategy": "all-ordered", "pickQuestions": 0, "questions": []}], "contributors": [{"name": "Ben Brawn", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/605/"}]}]}], "contributors": [{"name": "Ben Brawn", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/605/"}]}