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Question 1 · Single choice · 中档
2018 年 3 月《Nature》杂志上刊登了通过测量行星物质中 $^{48}\text{Ca}/^{44}\text{Ca}$ 的比值,揭示了行星演变的关系。$^{48}\text{Ca}$ 和 $^{44}\text{Ca}$ 具有( )
A. 相同的质量数 B. 不同的质子数 C. 相同的中子数 D. 相同的电子数
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Question 5 · Single choice · 中档
A. . 反应比较复杂 B. . 产率较高 C. . 副产物较多 D. . 反应速率较慢
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Question 6 · Single choice · 中档
A. . NH$_4$HCO$_3$ B. . NaHCO$_3$ C. . Al(OH)$_3$ D. . CaCO$_3$
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Question 7 · Single choice · 中档
A. . 含有非极性键 B. . 是直线形分子 C. . 属于极性分子 D. . 结构式为 $C=O=O$
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Question 8 · Single choice · 中档
A. . 铁遇浓硫酸发生钝化 B. . 蔗糖遇浓硫酸变黑 C. . 加热时碳与浓硫酸反应 D. . 加热时铜与浓硫酸反应
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Question 10 · Single choice · 中档
A. H₂S+O₂→SO₂ B. SO₂+H₂O→H₂SO₃ C. S+O₂→SO₃ D. SO₃+H₂O→H₂SO₄
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Question 11 · Single choice · 中档
侯氏制碱法中,使 NH₄Cl 从母液中析出的措施不包括( )
A. 通入二氧化碳 B. 冷却 C. 通入氨气 D. 加入研细的食盐
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Question 13 · Single choice · 中档
A. 浓氢溴酸,加热 B. NaOH/H₂O,加热 C. 浓硫酸,加热 D. NaOH/C₂H₅OH,加热
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Question 14 · Single choice · 中档
A. 是吸热反应 B. 在常压下进行 C. 在沸腾炉中进行 D. 使用铁触媒作催化剂
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Question 15 · Single choice · 中档
A. N₂的电子式为N:::N B. N³⁻的最外层电子数为6 C. N³⁻的质子数是20 D. 氮原子未成对电子的电子云形状相同
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Question 16 · Single choice · 中档
重量法测定硫酸铜晶体结晶水含量时,会引起测定值偏高的是( )
A. 未作恒重操作 B. 硫酸铜部分分解 C. 硫酸铜晶体未完全失水 D. 坩埚放在空气中冷却
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