Fe.

Cho phương trình hóa học của phản ứng như sau:<span style="overflow: hidden; display: inline-block; margin: 0.00px 0.00px; border: 0.00px solid #000000; transform: rotate(0.00rad) translateZ(0px); -webkit-transform: rotate(0.00rad) translateZ(0px); width: 301.50px; height: 27.41px;"><img alt='&lt;math xmlns="http://www.w3.org/1998/Math/MathML"&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;msub&gt;&lt;mi mathvariant="normal"&gt;H&lt;/mi&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msub&gt;&lt;mfenced&gt;&lt;mi mathvariant="normal"&gt;k&lt;/mi&gt;&lt;/mfenced&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;msub&gt;&lt;mi&gt;Fe&lt;/mi&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mi mathvariant="normal"&gt;O&lt;/mi&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;/msub&gt;&lt;mfenced&gt;&lt;mi mathvariant="normal"&gt;r&lt;/mi&gt;&lt;/mfenced&gt;&lt;mover&gt;&lt;mo&gt;&amp;#x2192;&lt;/mo&gt;&lt;msup&gt;&lt;mi mathvariant="normal"&gt;t&lt;/mi&gt;&lt;mi mathvariant="normal"&gt;o&lt;/mi&gt;&lt;/msup&gt;&lt;/mover&gt;&lt;mo&gt;&amp;#xA0;&lt;/mo&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;mi&gt;Fe&lt;/mi&gt;&lt;mfenced&gt;&lt;mi mathvariant="normal"&gt;r&lt;/mi&gt;&lt;/mfenced&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;msub&gt;&lt;mi mathvariant="normal"&gt;H&lt;/mi&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msub&gt;&lt;mi mathvariant="normal"&gt;O&lt;/mi&gt;&lt;mfenced&gt;&lt;mi mathvariant="normal"&gt;h&lt;/mi&gt;&lt;/mfenced&gt;&lt;mo&gt;.&lt;/mo&gt;&lt;/math&gt;' src="https://img-question-vn.ruangguru.com/1C3Zlwe5JpzAv9qAIHoEvj0ai_6W2TbPyM8n7g9Bb_fMlm8a-KPkfweGkG0o6g-QgEo2mUWZgusWFDue1YZ7mib1Sxtt_058A_GPxO45NF0oz0vep28Hi8s7Bj4pJZVASslDWzZJ" style="width: 301.50px; height: 27.41px; margin-left: 0.00px; margin-top: 0.00px; transform: rotate(0.00rad) translateZ(0px); -webkit-transform: rotate(0.00rad) translateZ(0px);" title="3 straight H subscript 2 open parentheses straight k close parentheses plus Fe subscript 2 straight O subscript 3 open parentheses straight r close parentheses rightwards arrow with straight t to the power of straight o on top space 2 Fe open parentheses straight r close parentheses plus 3 straight H subscript 2 straight O open parentheses straight h close parentheses."/> Chất đóng vai trò chất khử là

Phản ứng hóa học nào sau đây thuộc loại phản ứng oxi hóa - khử?

Cho sơ đồ chuỗi chuyển hóa của phản ứng sau:<span style="overflow: hidden; display: inline-block; margin: 0.00px 0.00px; border: 0.00px solid #000000; transform: rotate(0.00rad) translateZ(0px); -webkit-transform: rotate(0.00rad) translateZ(0px); width: 232.00px; height: 30.67px;"><img alt='&lt;math xmlns="http://www.w3.org/1998/Math/MathML"&gt;&lt;msub&gt;&lt;mi&gt;SO&lt;/mi&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;/msub&gt;&lt;mo&gt;&amp;#xA0;&lt;/mo&gt;&lt;mover&gt;&lt;mo&gt;&amp;#x2192;&lt;/mo&gt;&lt;mrow&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;msub&gt;&lt;mi mathvariant="normal"&gt;H&lt;/mi&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msub&gt;&lt;mi mathvariant="normal"&gt;O&lt;/mi&gt;&lt;/mrow&gt;&lt;/mover&gt;&lt;mi mathvariant="normal"&gt;X&lt;/mi&gt;&lt;mover&gt;&lt;mo&gt;&amp;#x2192;&lt;/mo&gt;&lt;mrow&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;mi&gt;Fe&lt;/mi&gt;&lt;/mrow&gt;&lt;/mover&gt;&lt;mi mathvariant="normal"&gt;Y&lt;/mi&gt;&lt;mover&gt;&lt;mo&gt;&amp;#x2192;&lt;/mo&gt;&lt;mrow&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;msub&gt;&lt;mi mathvariant="normal"&gt;O&lt;/mi&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/mover&gt;&lt;mo&gt;&amp;#xA0;&lt;/mo&gt;&lt;msub&gt;&lt;mi mathvariant="normal"&gt;H&lt;/mi&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msub&gt;&lt;mi mathvariant="normal"&gt;O&lt;/mi&gt;&lt;mo&gt;.&lt;/mo&gt;&lt;/math&gt;' src="https://img-question-vn.ruangguru.com/3905V4bHMV_-W4VowRo4b7O4AcxFOF2FYUwHxXOR4ail0ZzVmUrwMw1m6WPk6Yf1y9FnYKQGezUVc9FssM7suyLbJ7zWe44GWZMPe8363HI4bCoQWXGQl_a6jVsslBQnGyFYWqzJ" style="width: 232.00px; height: 30.67px; margin-left: 0.00px; margin-top: 0.00px; transform: rotate(0.00rad) translateZ(0px); -webkit-transform: rotate(0.00rad) translateZ(0px);" title="SO subscript 3 space rightwards arrow with plus straight H subscript 2 straight O on top straight X rightwards arrow with plus Fe on top straight Y rightwards arrow with plus straight O subscript 2 on top space straight H subscript 2 straight O."/> X, Y có công thức hóa học lần lượt là

Cho CaO vào nước.

Điện phân nước.

Nung nóng chất rắn <span style="overflow: hidden; display: inline-block; margin: 0.00px 0.00px; border: 0.00px solid #000000; transform: rotate(0.00rad) translateZ(0px); -webkit-transform: rotate(0.00rad) translateZ(0px); width: 52.00px; height: 16.00px;"><img alt='&lt;math xmlns="http://www.w3.org/1998/Math/MathML"&gt;&lt;msub&gt;&lt;mi&gt;KMnO&lt;/mi&gt;&lt;mn&gt;4&lt;/mn&gt;&lt;/msub&gt;&lt;/math&gt;' src="https://img-question-vn.ruangguru.com/2SnfouR5CMlCeGvVHYLVEOfDJVeN0jDDlFgC-gn-wp17zOgjQgrQS3o-KRGaLBDgOk84JlDnw7iDoa3N33CqHN_xXAVkx_m8Y7PHz_fvsMpQdlRFzuTbveF70XXjzx_MG_lTho20" style="width: 52.00px; height: 16.00px; margin-left: 0.00px; margin-top: 0.00px; transform: rotate(0.00rad) translateZ(0px); -webkit-transform: rotate(0.00rad) translateZ(0px);" title="KMnO subscript 4"/>.

Cho Fe vào dung dịch <span style="overflow: hidden; display: inline-block; margin: 0.00px 0.00px; border: 0.00px solid #000000; transform: rotate(0.00rad) translateZ(0px); -webkit-transform: rotate(0.00rad) translateZ(0px); width: 40.00px; height: 16.00px;"><img alt='&lt;math xmlns="http://www.w3.org/1998/Math/MathML"&gt;&lt;msub&gt;&lt;mi&gt;CuCl&lt;/mi&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msub&gt;&lt;/math&gt;' src="https://img-question-vn.ruangguru.com/QSVhAhTL-ByIIrEiDbqV4HyjPX3nXPzH5p7L6SNzlTwufYu3IZu-8v5M3YgvU91ktavPTbofSMggOA3XIvk9owliZ30QQ255Ck0TvqKy3kfiK5e4U6l6R7loLF7NeZG-EYhvd5hM" style="width: 40.00px; height: 16.00px; margin-left: 0.00px; margin-top: 0.00px; transform: rotate(0.00rad) translateZ(0px); -webkit-transform: rotate(0.00rad) translateZ(0px);" title="CuCl subscript 2"/>.

Thí nghiệm nào sau đây sinh ra khí hiđro?

11,2.

33,6.

5,6.

22,4.

Để khử hoàn toàn 31,3 gam hỗn hợp X gồm <span style="overflow: hidden; display: inline-block; margin: 0.00px 0.00px; border: 0.00px solid #000000; transform: rotate(0.00rad) translateZ(0px); -webkit-transform: rotate(0.00rad) translateZ(0px); width: 44.00px; height: 16.00px;"><img alt='&lt;math xmlns="http://www.w3.org/1998/Math/MathML"&gt;&lt;msub&gt;&lt;mi&gt;Fe&lt;/mi&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;/msub&gt;&lt;msub&gt;&lt;mi mathvariant="normal"&gt;O&lt;/mi&gt;&lt;mn&gt;4&lt;/mn&gt;&lt;/msub&gt;&lt;mo&gt;&amp;#xA0;&lt;/mo&gt;&lt;/math&gt;' src="https://img-question-vn.ruangguru.com/Qp3KWXjIo2bobGuP6tcDtfKdSFaJ3VMX_jNHlZoc6nLSjuLpOtvWAOiDwDFKikYOcvN1tBBSLU2WV5GhvJo3fe3mF4TSceidX0EeTQcficbgiizxYIgcVZQfJAfFDIBdHd-KXipx" style="width: 44.00px; height: 16.00px; margin-left: 0.00px; margin-top: 0.00px; transform: rotate(0.00rad) translateZ(0px); -webkit-transform: rotate(0.00rad) translateZ(0px);" title="Fe subscript 3 straight O subscript 4 space"/> và ZnO có tỉ lệ số mol 1:1 cần dùng vừa đủ V lít khí <span style="overflow: hidden; display: inline-block; margin: 0.00px 0.00px; border: 0.00px solid #000000; transform: rotate(0.00rad) translateZ(0px); -webkit-transform: rotate(0.00rad) translateZ(0px); width: 17.33px; height: 16.00px;"><img alt='&lt;math xmlns="http://www.w3.org/1998/Math/MathML"&gt;&lt;msub&gt;&lt;mi mathvariant="normal"&gt;H&lt;/mi&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msub&gt;&lt;/math&gt;' src="https://img-question-vn.ruangguru.com/L3MT44Wa-Zdvy2icj2eGPou7pV-ie37FiSdBsKaKmZSBZ0TUOSZZxoXDviyp-eYe5rD9665a1SI5SJv_WsVSgbgOuD9KLiUmVw8BwrFpUJQMTHX4nXmlb_1lSntPdZSycn5jUiM7" style="width: 17.33px; height: 16.00px; margin-left: 0.00px; margin-top: 0.00px; transform: rotate(0.00rad) translateZ(0px); -webkit-transform: rotate(0.00rad) translateZ(0px);" title="straight H subscript 2"/> (đktc). Giá trị của V là (cho O=16, Fe=56, Zn=65 g/mol)

2.

3.

1.

4.

Cho sơ đồ phản ứng hóa học sau:<span style="overflow: hidden; display: inline-block; margin: 0.00px 0.00px; border: 0.00px solid #000000; transform: rotate(0.00rad) translateZ(0px); -webkit-transform: rotate(0.00rad) translateZ(0px); width: 173.33px; height: 54.67px;"><img alt='&lt;math xmlns="http://www.w3.org/1998/Math/MathML"&gt;&lt;mi&gt;Zn&lt;/mi&gt;&lt;mo&gt;&amp;#xA0;&lt;/mo&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;mo&gt;&amp;#xA0;&lt;/mo&gt;&lt;mi&gt;HCl&lt;/mi&gt;&lt;mo&gt;&amp;#xA0;&lt;/mo&gt;&lt;mo&gt;&amp;#x2192;&lt;/mo&gt;&lt;mo&gt;&amp;#xA0;&lt;/mo&gt;&lt;mi mathvariant="normal"&gt;X&lt;/mi&gt;&lt;mo&gt;&amp;#xA0;&lt;/mo&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;mo&gt;&amp;#xA0;&lt;/mo&gt;&lt;mi mathvariant="normal"&gt;Y&lt;/mi&gt;&lt;mo&gt;&amp;#xA0;&lt;/mo&gt;&lt;mspace linebreak="newline"/&gt;&lt;mi&gt;CuO&lt;/mi&gt;&lt;mo&gt;&amp;#xA0;&lt;/mo&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;mo&gt;&amp;#xA0;&lt;/mo&gt;&lt;mi mathvariant="normal"&gt;Y&lt;/mi&gt;&lt;mover&gt;&lt;mo&gt;&amp;#x2192;&lt;/mo&gt;&lt;msup&gt;&lt;mi mathvariant="normal"&gt;t&lt;/mi&gt;&lt;mi mathvariant="normal"&gt;o&lt;/mi&gt;&lt;/msup&gt;&lt;/mover&gt;&lt;mo&gt;&amp;#xA0;&lt;/mo&gt;&lt;mi mathvariant="normal"&gt;Z&lt;/mi&gt;&lt;mo&gt;&amp;#xA0;&lt;/mo&gt;&lt;mo&gt;+&lt;/mo&gt;&lt;mo&gt;&amp;#xA0;&lt;/mo&gt;&lt;msub&gt;&lt;mi mathvariant="normal"&gt;H&lt;/mi&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msub&gt;&lt;mi mathvariant="normal"&gt;O&lt;/mi&gt;&lt;mo&gt;.&lt;/mo&gt;&lt;/math&gt;' src="https://img-question-vn.ruangguru.com/lmdGXBo27DgWk-Trav7_7nkD_HZfQXqfkUQtD1b05gMZUyICjFw7Np0vOwGNQeOopMoA5GoqLnmLmQFo21aTaUhnyjRxHE7TrPM6M5B6MDFo3w50-MrOMJ_P7Uvnwulp5TnGiwpA" style="width: 173.33px; height: 54.67px; margin-left: 0.00px; margin-top: 0.00px; transform: rotate(0.00rad) translateZ(0px); -webkit-transform: rotate(0.00rad) translateZ(0px);" title="Zn space plus space HCl space rightwards arrow space straight X space plus space straight Y space
CuO space plus space straight Y rightwards arrow with straight t to the power of straight o on top space straight Z space plus space straight H subscript 2 straight O."/> X, Y, Z có công thức hóa học lần lượt là

19,6.

44,45.

25,55.

14.

Hòa tan hoàn toàn m gam Fe vào dung dịch HCl thu được 7,84 lít khí hiđro (đktc). Giá trị của m là (cho H=1; Cl=35,5; Fe=56 g/mol)

5.

4.

3.

2.

Cho các chất sau:<span style="overflow: hidden; display: inline-block; margin: 0.00px 0.00px; border: 0.00px solid #000000; transform: rotate(0.00rad) translateZ(0px); -webkit-transform: rotate(0.00rad) translateZ(0px); width: 178.67px; height: 16.00px;"><img alt='&lt;math xmlns="http://www.w3.org/1998/Math/MathML"&gt;&lt;msub&gt;&lt;mi mathvariant="normal"&gt;O&lt;/mi&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msub&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;mo&gt;&amp;#xA0;&lt;/mo&gt;&lt;mi&gt;FeO&lt;/mi&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;mo&gt;&amp;#xA0;&lt;/mo&gt;&lt;mi&gt;CuO&lt;/mi&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;mo&gt;&amp;#xA0;&lt;/mo&gt;&lt;mi&gt;PbO&lt;/mi&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;mo&gt;&amp;#xA0;&lt;/mo&gt;&lt;msub&gt;&lt;mi mathvariant="normal"&gt;H&lt;/mi&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msub&gt;&lt;mi mathvariant="normal"&gt;O&lt;/mi&gt;&lt;/math&gt;' src="https://img-question-vn.ruangguru.com/blXt0OMPq7ZnG-SS2qcT3QE6X_MvINSx-ow40x4Doz9G9gqlGAxRKaimipkGzeFFamd38LdfObW5PwsjvkJLMKM7Wy8e4fCij_bNXMyQ4jTPbQq81eTIqXt19Wd3rUpfL3tQA6zT" style="width: 178.67px; height: 16.00px; margin-left: 0.00px; margin-top: 0.00px; transform: rotate(0.00rad) translateZ(0px); -webkit-transform: rotate(0.00rad) translateZ(0px);" title="straight O subscript 2 comma space FeO comma space CuO comma space PbO comma space straight H subscript 2 straight O"/>. Số chất tác dụng với <span style="overflow: hidden; display: inline-block; margin: 0.00px 0.00px; border: 0.00px solid #000000; transform: rotate(0.00rad) translateZ(0px); -webkit-transform: rotate(0.00rad) translateZ(0px); width: 17.33px; height: 16.00px;"><img alt='&lt;math xmlns="http://www.w3.org/1998/Math/MathML"&gt;&lt;msub&gt;&lt;mi mathvariant="normal"&gt;H&lt;/mi&gt;&lt;mn&gt;2&lt;/mn&gt;&lt;/msub&gt;&lt;/math&gt;' src="https://img-question-vn.ruangguru.com/7JgiQhvDs9a_Rd6QInOh9jOkkGAPu4XJDINLcw8Ih4Ty7pnV7MgyYdDcIEIPOs3rCvYcuvYgpK3URTe70eSBFiQuS2GqjwD5tFyHO4g9qEORHEvmIwGvV6_7vy2h7z3Khwl0iW9Y" style="width: 17.33px; height: 16.00px; margin-left: 0.00px; margin-top: 0.00px; transform: rotate(0.00rad) translateZ(0px); -webkit-transform: rotate(0.00rad) translateZ(0px);" title="straight H subscript 2"/> ở điều kiện thích hợp là

1.

3.

4.

Cho các khí sau: oxi, nitơ, cacbonic, hiđro. Chỉ dùng que đóm đang cháy và nước vôi trong có thể phân biệt được bao nhiêu chất khí?

36.

28,8.

40.

48.

Hòa tan hoàn toàn hỗn hợp X gồm 13 gam Zn và 14 gam Fe vào dung dịch HCl, dẫn toàn bộ lượng khí hiđro vào ống đựng CuO đã được nung nóng, thấy có m gam CuO phản ứng. Giá trị của m là