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{"name": "Molecular Weights", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "question_groups": [{"pickingStrategy": "all-ordered", "questions": [{"functions": {}, "metadata": {"licence": "Creative Commons Attribution 4.0 International", "description": "<p>Calculating molecular weights.</p>"}, "extensions": [], "variablesTest": {"maxRuns": 100, "condition": ""}, "variables": {"h_1": {"description": "", "name": "h_1", "definition": "random(1..12)", "group": "Ungrouped variables", "templateType": "anything"}, "ca": {"description": "<p>Standard atomic weight of calcium</p>", "name": "ca", "definition": "40.078", "group": "Ungrouped variables", "templateType": "anything"}, "o_1": {"description": "", "name": "o_1", "definition": "random(1..12)", "group": "Ungrouped variables", "templateType": "anything"}, "Molecule_weights": {"description": "", "name": "Molecule_weights", "definition": "[ 19, 12 ]", "group": "Ungrouped variables", "templateType": "list of numbers"}, "h": {"description": "<p>Standard atomic weight of hydrogen</p>", "name": "h", "definition": "1.008", "group": "Ungrouped variables", "templateType": "anything"}, "c": {"description": "<p>Standard atomic weight of carbon</p>", "name": "c", "definition": "12.011", "group": "Ungrouped variables", "templateType": "anything"}, "o": {"description": "<p>Standard atomic weight of oxygen</p>", "name": "o", "definition": "15.999", "group": "Ungrouped variables", "templateType": "anything"}, "Molecule_indices": {"description": "", "name": "Molecule_indices", "definition": "deal(2)", "group": "Ungrouped variables", "templateType": "anything"}, "c_1": {"description": "", "name": "c_1", "definition": "random(1..12)", "group": "Ungrouped variables", "templateType": "anything"}, "p": {"description": "<p>Standard atomic weight of phosporus</p>", "name": "p", "definition": "30.974", "group": "Ungrouped variables", "templateType": "anything"}, "Molecule_names": {"description": "", "name": "Molecule_names", "definition": "[ \"H_2O\", \"CO_2\" ]", "group": "Ungrouped variables", "templateType": "list of strings"}}, "preamble": {"js": "", "css": ""}, "variable_groups": [], "name": "Molecular Weights", "statement": "<p>Calculate the&nbsp;molecular weights of the following molecules. Use the standard atomic weights given below:</p>\n<p>Calcium ($Ca$): $\\var{ca}$</p>\n<p>Carbon ($C$): $\\var{c}$</p>\n<p>Hydrogen ($H$): $\\var{h}$</p>\n<p>Oxygen ($O$): $\\var{o}$</p>\n<p>Phosporus ($P$): $\\var{p}$</p>\n<p>Please enter your answers as decimals, not as fractions. Give your answers to 3 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>", "tags": ["molecular mass", "Molecular mass", "molecular weight", "Molecular weight", "Relative molecular mass", "RMM"], "ungrouped_variables": ["h_1", "ca", "o_1", "p", "Molecule_weights", "Molecule_indices", "c_1", "h", "o", "c", "Molecule_names"], "parts": [{"correctAnswerStyle": "plain", "showFeedbackIcon": true, "prompt": "<p>Water - $H_2O$.</p>", "variableReplacements": [], "showCorrectAnswer": true, "mustBeReduced": false, "maxValue": "2*h+o+0.0005", "allowFractions": false, "type": "numberentry", "correctAnswerFraction": false, "minValue": "2*h+o-0.0005", "mustBeReducedPC": 0, "notationStyles": ["plain", "en", "si-en"], "scripts": {}, "variableReplacementStrategy": "originalfirst", "marks": 1}, {"correctAnswerStyle": "plain", "showFeedbackIcon": true, "prompt": "<p>Methane - $CH_4$.</p>", "variableReplacements": [], "showCorrectAnswer": true, "mustBeReduced": false, "maxValue": "c+4*h+0.0005", "allowFractions": false, "type": "numberentry", "correctAnswerFraction": false, "minValue": "c+4*h-0.0005", "mustBeReducedPC": 0, "notationStyles": ["plain", "en", "si-en"], "scripts": {}, "variableReplacementStrategy": "originalfirst", "marks": 1}, {"correctAnswerStyle": "plain", "showFeedbackIcon": true, "prompt": "<p>Glucose - $C_6H_{12}O_6$.</p>", "variableReplacements": [], "showCorrectAnswer": true, "mustBeReduced": false, "maxValue": "6*c+12*h+6*o+0.0005", "allowFractions": false, "type": "numberentry", "correctAnswerFraction": false, "minValue": "6*c+12*h+6*o-0.0005", "mustBeReducedPC": 0, "notationStyles": ["plain", "en", "si-en"], "scripts": {}, "variableReplacementStrategy": "originalfirst", "marks": 1}, {"correctAnswerStyle": "plain", "showFeedbackIcon": true, "prompt": "<p>Calcium Phosphate - $Ca_3(PO_4)_2$.</p>", "variableReplacements": [], "showCorrectAnswer": true, "mustBeReduced": false, "maxValue": "3*ca+2*p+8*o+0.0005", "allowFractions": false, "type": "numberentry", "correctAnswerFraction": false, "minValue": "3*ca+2*p+8*o-0.0005", "mustBeReducedPC": 0, "notationStyles": ["plain", "en", "si-en"], "scripts": {}, "variableReplacementStrategy": "originalfirst", "marks": 1}], "advice": "<p>a) Water - $H_2O$.</p>\n<p>A water molecule has 2 hydrogen atoms ($H$) and 1 oxygen atom ($O$) so the molecular weight is</p>\n<p style=\"text-align: center;\">$2 \\times \\var{h} + \\var{o} = \\var{2 * h + o}$.</p>\n<p style=\"text-align: left;\"></p>\n<p style=\"text-align: left;\">b) Methane - $CH_4$.</p>\n<p style=\"text-align: left;\">A methane molecule has 1 carbon atom ($C$) and 4 hydrogen atoms ($H$) so the molecular weight is</p>\n<p style=\"text-align: center;\">$\\var{c} + 4 \\times \\var{h} = \\var{c + 4 * h}$.</p>\n<p style=\"text-align: center;\"></p>\n<p style=\"text-align: left;\">c) Glucose - $C_6H_{12}O_6$.</p>\n<p style=\"text-align: left;\">A glucose molecule has 6 carbon atoms ($C$), 12 hydrogen atoms ($H$) and 6 oxygen atoms ($O$) so the molecular weight is&nbsp;</p>\n<p style=\"text-align: center;\">$6 \\times \\var{c} + 12 \\times \\var{h} + 6 \\times \\var{o} = \\var{6 * c + 12 * h + 6 * o}$.</p>\n<p style=\"text-align: center;\"></p>\n<p style=\"text-align: left;\">d) Calcium phospate - $Ca_3(PO_4)_2$.</p>\n<p style=\"text-align: left;\">A calcium phosphate molecule has 3 calcium atoms ($Ca$) and 2 phosphate ions ($PO_4$). We don't need to worry too much about what an ion is here, we just need to know that $(PO_4)_2$ means there are 2 lots of $PO_4$ which means a total of 2 phosporus atoms ($P$) and $4 \\times 2 = 8$ oxygen atoms ($O$). Therefore, the molecular weight is&nbsp;</p>\n<p style=\"text-align: center;\">$3 \\times \\var{ca} + 2 \\times \\var{p} + 8 \\times \\var{o} = \\var{3 * ca + 2 * p + 8 * o}$.</p>", "rulesets": {}, "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/"}]}