}_2\\text{O}(\\text{l}) + \\text{CO}_2(\\text{g})\\]","markscheme":"- Completes the equation with $\\text{CaCl}_2$ B1","marks":1,"order":0,"markingRubric":null,"explanation":null,"options":[]},{"id":"a92893f7-501a-4e54-adf6-a867d6717f19","label":"b","content":"Hydrochloric acid has the state symbol \$\\text{(aq)}\$.\n\nWhat does \$\\text{(aq)}\$ mean?","markscheme":"- Explains that $\\text{(aq)}$ means aqueous or dissolved in water B1","marks":1,"order":1,"markingRubric":null,"explanation":null,"options":[]},{"id":"7d559d81-fbf4-48dc-a009-efcc69bf258b","label":"c","content":"Name a common piece of laboratory apparatus that can be connected to the reaction flask to collect and measure the volume of carbon dioxide gas produced.","markscheme":"- Names \"gas syringe\" (or inverted measuring cylinder / burette filled with water) B1","marks":1,"order":2,"markingRubric":null,"explanation":null,"options":[]},{"id":"676a0bad-e2d6-4a93-be29-787bf6c7e14c","label":"d","content":"### Part (b)\n\nThe table below shows the student's results during the reaction:\n\n| Time (minutes) | Volume of gas collected (\$\\text{cm}^3\$) |\n| :---: | :---: |\n| 0 | 0.0 |\n| 1 | 8.0 |\n| 2 | 14.0 |\n| 3 | 18.0 |\n| 4 | 21.0 |\n| 5 | 23.0 |\n| 6 | 24.0 |\n| 7 | 24.0 |\n| 8 | 24.0 |\n\nAt what time was the reaction complete?","markscheme":"- Identifies that the reaction is complete at $6\\text{ minutes}$ (when volume remains constant at $24.0\\text{ cm}^3$) B1","marks":1,"order":3,"markingRubric":null,"explanation":null,"options":[]},{"id":"3bc58553-627a-4aa7-b4ec-ac4de9695f6e","label":"e","content":"By drawing a smooth curve of best fit through these data points, estimate the volume of gas collected at \$3.5\\text{ minutes}\$.","markscheme":"- Estimates the volume of gas at $3.5\\text{ minutes}$ to be in the range $19.5\\text{ cm}^3$ to $20.0\\text{ cm}^3$ B1","marks":1,"order":4,"markingRubric":null,"explanation":null,"options":[]},{"id":"06e573b1-909f-49e5-83de-14f1756306ab","label":"f","content":"The student wishes to collect a larger volume of gas. Assuming the calcium carbonate solid is in excess, which of the following changes to the experiment should the student make?\n- Use a larger conical flask\n- Use less calcium carbonate\n- Use more hydrochloric acid\n- Lower the temperature of the acid","markscheme":"- Selects \"Use more hydrochloric acid\" B1","marks":1,"order":5,"markingRubric":null,"explanation":null,"options":[]}],"options":[],"explanation":null,"firstAttemptFullMarks":null}],"subjectCode":"gcse_chemistry__ocr","summaries":[{"id":"0327ccbe-025f-47d1-a798-31e8133c3d32","difficultyBand":"easy","calculatorUse":null},{"id":"04f479a4-02a4-456a-a18c-5570af6d448b","difficultyBand":"medium","calculatorUse":null},{"id":"06d822f8-5a77-4850-a369-f6979471aee3","difficultyBand":"medium","calculatorUse":null},{"id":"07694ad4-699e-42ce-b613-00e38ef9290c","difficultyBand":"easy","calculatorUse":null},{"id":"08870bd8-c7ac-4466-ad57-c5f2e1199f63","difficultyBand":"easy","calculatorUse":null},{"id":"09b24b17-6c07-4d84-b68f-f45f11559611","difficultyBand":"medium","calculatorUse":null},{"id":"0b7601c2-5a8d-487b-b0b9-8e69832ba79d","difficultyBand":"medium","calculatorUse":null},{"id":"0cb1ebef-7f08-44e3-9cfc-249c77b7b6be","difficultyBand":"medium","calculatorUse":null},{"id":"0d66df09-5c61-43f3-a031-2297dacda784","difficultyBand":"easy","calculatorUse":null},{"id":"0df6aca2-7540-48ac-83b6-7bcaaa2e8e24","difficultyBand":"easy","calculatorUse":null},{"id":"0f2a7cd4-9765-4018-9f7d-9721f3145f73","difficultyBand":"medium","calculatorUse":null},{"id":"0f42f3bb-04d6-47fa-9e71-b1c7ad4ad042","difficultyBand":"medium","calculatorUse":null},{"id":"0f4c5412-6349-4fa1-8784-29bba256f78f","difficultyBand":"medium","calculatorUse":null},{"id":"10a2e359-710b-4274-8f63-37dd31c54031","difficultyBand":"easy","calculatorUse":null},{"id":"126b15a7-c5ff-4e00-bc56-52f696367d60","difficultyBand":"medium","calculatorUse":null},{"id":"171af324-6ee6-4261-bf89-014db0dd2cfa","difficultyB

Monitoring chemical reactions

Question 7

Monitoring chemical reactions Questions

Monitoring chemical reactions

Question 7

Monitoring chemical reactions Questions