【Daily Question】July 2, 2016: +2 wealth for participation； +3 to 8 wealth for correct answers
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To increase the popularity of the chemical analysis section, a \"One Question per Day\" campaign has been launched to foster an active atmosphere for technical exchanges while also providing rewards in the form of financial benefits to users. 【Daily Question】 (Single-choice question) When preparing a 0.1 mol L-1 NaOH standard solution, which of the following methods is incorrect? (M=40 g/mol) ( ) A. Prepare a saturated solution of NaOH, store it in a polyethylene plastic bottle, keep it sealed until the solution becomes clear; then take 5 ml of this clear solution and add it to 1 liter of CO2-free water, stir well, and store the resulting solution in a colorless reagent bottle. B. Dissolve 4.02 grams of NaOH in 1 liter of water, heat while stirring, and store the solution in a ground-glass stoppered flask. C. Dissolve 4 grams of NaOH in 1 liter of water, heat while stirring, and store the solution in a colorless reagent bottle. D. Dissolve 2 grams of NaOH in 500 ml of water, heat while stirring, and store the solution in a colorless reagent bottle. Correct answer: B. Please reply with your answer; participating in the quiz earns you +2 points. Those who get all answers correct will receive an additional +3 to +8 points. Those who provide thorough analyses or detailed calculation processes for the questions and answers will receive extra points as well. If your answer is correct and your analysis is accurate, it will be marked as the best reply. Feel free to answer the questions.
B. Dissolve 4.02 grams of NaOH in 1 liter of water, heat while stirring, and store in a ground-glass flask
To prepare a 0.1 mol L-1 NaOH standard solution, which of the following methods is incorrect? (M=40 g/mol) (A) A. Prepare a saturated solution of NaOH, store it in a polyethylene plastic bottle, keep it sealed until the solution becomes clear; then take 5 ml of this clear solution and add it to 1 liter of CO2-free water, stir well, and store the resulting solution in a colorless reagent bottle. B. Dissolve 4.02 grams of NaOH in 1 liter of water, heat while stirring, and store the solution in a ground-glass flask. C. Dissolve 4 grams of NaOH in 1 liter of water, heat while stirring, and store the solution in a colorless reagent bottle. D. Dissolve 2 grams of NaOH in 500 ml of water, heat while stirring, and store the solution in a colorless reagent bottle
B. Dissolve 4.02 grams of NaOH in 1 liter of water, heat while stirring, and store in a ground-glass flask