d is an example of a weak acid.","markscheme":"- Identifies \"Alkalis form $\\text{OH}^-$ ions in aqueous solution\" as the correct statement B1","marks":1,"order":0,"markingRubric":null,"explanation":null,"options":[]},{"id":"18cc3ba3-3ef4-4ec4-b02a-c4111ce2559e","label":"b","content":"A chemist reacts dilute nitric acid with insoluble zinc carbonate, \$\\text{ZnCO}_3\$. They repeat the experiment two more times.\n\nThe table below shows their results:\n\n| | Experiment 1 | Experiment 2 | Experiment 3 |\n| :--- | :---: | :---: | :---: |\n| Mass of zinc nitrate, \$\\text{Zn(NO}_3)_2\$, produced (g) | 6.34 | 6.27 | 6.31 |\n| Mass of zinc carbonate, \$\\text{ZnCO}_3\$, remaining (g) | 1.45 | 1.52 | 1.48 |\n\nCalculate the mean mass of zinc nitrate, \$\\text{Zn(NO}_3)_2\$, made. Give your answer to 3 significant figures.","markscheme":"- Sums the three mass values: $6.34 + 6.27 + 6.31 = 18.92$ M1\n- Divides by $3$ to calculate the mean and rounds to 3 significant figures: $6.31\\text{ g}$ A1","marks":2,"order":1,"markingRubric":null,"explanation":null,"options":[]},{"id":"e2867467-5741-4e84-a6f3-20b01fca8420","label":"c","content":"Complete the balanced symbol equation for the reaction. Include state symbols.\n\\[2\\text{HNO}_3(\\text{aq}) + \\text{ZnCO}_3(\\text{s}) \\rightarrow \\text{Zn(NO}_3)_2(\\text{aq}) + \\dots\\dots\\dots\\dots\\dots (\\dots\\dots) + \\dots\\dots\\dots\\dots\\dots (\\dots\\dots)\\]","markscheme":"- Identifies the chemical formulas of the missing products: $\\text{H}_2\\text{O}$ and $\\text{CO}_2$ B1\n- Gives the correct state symbols: $(\\text{l})$ for water and $(\\text{g})$ for carbon dioxide B1","marks":2,"order":2,"markingRubric":null,"explanation":null,"options":[]},{"id":"a39a1733-9a8d-40ae-b31a-9d5bd898f154","label":"d","content":"How does the chemist remove the unreacted solid zinc carbonate, \$\\text{ZnCO}_3(\\text{s})\$?","markscheme":"- Identifies filtration (or filtering) as the method to remove the excess solid zinc carbonate B1","marks":1,"order":3,"markingRubric":null,"explanation":null,"options":[]},{"id":"d6158073-c4a6-4537-b57f-3558f8e0cc38","label":"e","content":"How does the chemist obtain pure dry zinc nitrate crystals from zinc nitrate solution?","markscheme":"- Describes crystallisation (or evaporating the water until crystallisation point, allowing to cool, and drying the crystals) to obtain pure dry crystals B1","marks":1,"order":4,"markingRubric":null,"explanation":null,"options":[]}],"options":[],"explanation":null,"firstAttemptFullMarks":null}],"subjectCode":"gcse_chemistry__ocr","summaries":[{"id":"0424bdac-ebab-48b2-82de-2dc5db77c992","difficultyBand":"easy","calculatorUse":null},{"id":"04fdf832-d977-4bc4-8087-4b2d2910aad7","difficultyBand":"easy","calculatorUse":null},{"id":"090c5a14-6608-4af8-9d19-671df3b1eead","difficultyBand":"medium","calculatorUse":null},{"id":"149e657b-b013-4c1a-8893-75e4182f3409","difficultyBand":"easy","calculatorUse":null},{"id":"179d20ee-1295-47f7-91b7-a8520b31d760","difficultyBand":"easy","calculatorUse":null},{"id":"19a264c1-39ba-4d3f-a5a5-ca5f63184836","difficultyBand":"easy","calculatorUse":null},{"id":"1d6abf4a-f342-45f9-86b2-c345ee635c47","difficultyBand":"medium","calculatorUse":null},{"id":"1fb0432e-3a69-47bb-8444-1b1b89f16610","difficultyBand":"easy","calculatorUse":null},{"id":"20114784-0e64-4a75-8c4d-7e7dec62788e","difficultyBand":"easy","calculatorUse":null},{"id":"2789b007-5559-4922-97e3-187b68c2085c","difficultyBand":"medium","calculatorUse":null},{"id":"2bbd901c-b4a9-41e7-b700-caf6854d708f","difficultyBand":"medium","calculatorUse":null},{"id":"2bfe0a53-d507-4229-9ce2-234f3a558f02","difficultyBand":"easy","calculatorUse":null},{"id":"32285eea-99f3-4907-bcee-af8099ab9fad","difficultyBand":"medium","calculatorUse":null},{"id":"34a25044-51da-4faa-93da-7b2c512fbe9c","difficultyBand":"medium","calculatorUse":null},{"id":"35d11b64-5fa8-47d3-b3b3-3d113e3ee2c7","difficultyBand":"medium","calculatorUse":null},{"id":"3bd598

Types of chemical reactions

Question 22

Types of chemical reactions Questions

Types of chemical reactions

Question 22

Types of chemical reactions Questions