// Numbas version: exam_results_page_options
{"name": "Solutions 2", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "question_groups": [{"pickingStrategy": "all-ordered", "questions": [{"name": "Solutions 2", "variablesTest": {"maxRuns": 100, "condition": ""}, "variable_groups": [], "extensions": [], "rulesets": {}, "preamble": {"css": "", "js": ""}, "metadata": {"licence": "Creative Commons Attribution 4.0 International", "description": "<p>Practice calculating number of moles of a substance given the concentration and volume of a solution.</p>"}, "tags": ["concentration", "molarity", "moles", "solutions"], "ungrouped_variables": ["a", "c", "b", "d"], "parts": [{"type": "gapfill", "scripts": {}, "showFeedbackIcon": true, "prompt": "<p>How many moles of glucose are there in $\\var{a}$L of a $\\var{0.25 * b}$M (mol/L) solution?</p>\n<p>[[0]] moles</p>", "gaps": [{"type": "numberentry", "allowFractions": false, "showPrecisionHint": false, "showFeedbackIcon": true, "notationStyles": ["plain", "en", "si-en"], "correctAnswerFraction": false, "precisionMessage": "You have not given your answer to the correct precision.", "mustBeReduced": false, "variableReplacements": [], "maxValue": "a * (0.25 * b)", "marks": 1, "precisionType": "dp", "precisionPartialCredit": 0, "correctAnswerStyle": "plain", "scripts": {}, "strictPrecision": false, "showCorrectAnswer": true, "minValue": "a * (0.25 * b)", "variableReplacementStrategy": "originalfirst", "mustBeReducedPC": 0, "precision": "2"}], "showCorrectAnswer": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "marks": 0}, {"type": "gapfill", "scripts": {}, "showFeedbackIcon": true, "prompt": "<p>How many moles of glucose are there in $\\var{25 * c}$mL of a $\\var{0.25 * d}$M (mol/L) solution?</p>\n<p>[[0]] moles</p>", "gaps": [{"type": "numberentry", "allowFractions": false, "showPrecisionHint": false, "showFeedbackIcon": true, "notationStyles": ["plain", "en", "si-en"], "correctAnswerFraction": false, "precisionMessage": "You have not given your answer to the correct precision.", "mustBeReduced": false, "variableReplacements": [], "maxValue": "(25 * c / 1000) * 0.25 * d + 0.005", "marks": 1, "precisionType": "dp", "precisionPartialCredit": 0, "correctAnswerStyle": "plain", "scripts": {}, "strictPrecision": false, "showCorrectAnswer": true, "minValue": "(25 * c / 1000) * 0.25 * d - 0.005", "variableReplacementStrategy": "originalfirst", "mustBeReducedPC": 0, "precision": "2"}], "showCorrectAnswer": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "marks": 0}], "variables": {"d": {"name": "d", "description": "", "definition": "random(4..20)", "group": "Ungrouped variables", "templateType": "anything"}, "b": {"name": "b", "description": "", "definition": "random(1..10)", "group": "Ungrouped variables", "templateType": "anything"}, "a": {"name": "a", "description": "", "definition": "random(1..5)", "group": "Ungrouped variables", "templateType": "anything"}, "c": {"name": "c", "description": "", "definition": "random(2..10)", "group": "Ungrouped variables", "templateType": "anything"}}, "advice": "<p>To answer these questions, we use the formula</p>\n<p style=\"text-align: center;\">$\\text{volume of liquid (in litres)} \\times \\text{concentration (in mol/L)} = \\text{number of moles of substance}$.</p>\n<h4 style=\"text-align: left;\">a)</h4>\n<p style=\"text-align: left;\">How many moles of glucose are there in $\\var{a}$L of a $\\var{0.25 * b}$M (mol/L) solution?</p>\n<p style=\"text-align: left;\">Solution:</p>\n<p style=\"text-align: left;\">Putting our numbers into the formula, we find that there are</p>\n<p style=\"text-align: center;\">$\\var{a} \\times \\var{0.25 * b} = \\var{a * 0.25 * b}$ moles</p>\n<p style=\"text-align: left;\">of glucose in $\\var{a}$L of a $\\var{0.25 * b}$M (mol/L) solution.</p>\n<h4 style=\"text-align: left;\">b)</h4>\n<p style=\"text-align: left;\">How many moles of glucose are there in $\\var{25 * c}$mL of a $\\var{0.25 * d}$M (mol/L) solution?</p>\n<p style=\"text-align: left;\">Solution:</p>\n<p style=\"text-align: left;\">Our formula uses the volume of liquid in litres so first we have to convert $\\var{25 * c}$mL to a volume in litres. There are 1000ml in 1L so $\\var{25 * c}$mL is equal to&nbsp;</p>\n<p style=\"text-align: center;\">$\\dfrac{\\var{25 * c}}{1000} = \\var{25 * c / 1000}$L.</p>\n<p>Putting our numbers into the formula, we find that there are</p>\n<p style=\"text-align: center;\">$\\begin{align}\\var{25 * c / 1000} \\times \\var{0.25 * d} &amp; = \\var{(25 * c / 1000) *&nbsp;0.25 * d} \\text{ moles} \\\\ &amp; = \\var{precround(((25 * c / 1000) *&nbsp;0.25 * d),2 )} \\text{ moles to 2 d.p.}\\end{align}$</p>\n<p></p>\n<p>of glucose in $\\var{25 * c}$mL of a $\\var{0.25 * d}$M (mol/L) solution.</p>", "functions": {}, "statement": "<p>Answer the following questions. Please enter your answers as decimals, not as fractions. Give your answers to 2 decimal places.</p>\n<p>If you would like to see how to do this question, click on 'Reveal answers' at the bottom of the page.</p>", "type": "question", "contributors": [{"name": "Jamie Antoun", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/266/"}]}]}], "contributors": [{"name": "Jamie Antoun", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/266/"}]}