RRB JE Exam: Chemistry (Chemical Reactions) Quiz | 2 March

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Q1. Oxidation is defined as–
ऑक्सीकरण को किसके रूप में परिभाषित किया जाता है
(a) Loss of electrons/ इलेक्ट्रॉन प्रदान करना
(b) Gain of electrons/ इलेक्ट्रॉनों प्राप्त करना
(c) Gain of protons/ प्रोटॉन प्राप्त करना
(d) Loss of protons/ प्रोटॉन प्रदान करना

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Sol. Oxidation is the loss of electrons during a reaction by a molecule, atom or ion.

Q2. A reducing agent is a substance which can–
अपचायक घटक एक पदार्थ है जो _____ सकता है
(a) Accept electrons/ इलेक्ट्रॉनों को स्वीकार कर
(b) Donate electrons/ इलेक्ट्रॉनों प्रदान कर
(c) Accept protons/ प्रोटॉन स्वीकार कर
(d) Donate protons/प्रोटॉन प्रदान कर

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Sol. A reducing agent is oxidized, because it loses electrons in the redox reaction.

Q3. The common oxidation state of alkali metals in the combined state is–
संयुक्त अवस्था में क्षार धातुओं का सामान्य ऑक्सीकरण अवस्था क्या है
(a) +1
(b) +2
(c) –1
(d) –2

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Sol. Oxygen (O) has oxidation number -2, except in peroxides where it is –1. The alkali metals (Group 1) have 1 valence. This is lost to achieve noble gas configuration, and so alkali metals have oxidation number +1.

(a) +2, 0
(b) 0, 2
(c) 0, 8
(d) 6, 2

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Sol. The oxidation number and covalency of Sulphur in S8 is 0, 2.

(a) Oxidation/ ऑक्सीकरण
(b) Reduction/ अपचयन
(c) Simple dissolution/ सरल विघटन
(d) Double decomposition/ दोहरा अपघटन

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Sol. Oxidation means the addition of oxygen to a molecule or the removal of hydrogen from a molecule. In this equation Zn is gain of oxygen.

Q6. Which one of the following is a reduction reaction?
निम्नलिखित में से कौन सी अपचयन प्रतिक्रिया है

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Sol. 2 MgO (s) → 2 Mg (s) + O2(g).

Q7. Oxidation-reduction reaction involves
ऑक्सीकरण- अपचयन अभिक्रिया में शामिल है
(a) Transfer of neutrons/ न्यूट्रॉन का स्थानांतरण
(b) Transfer of protons/ प्रोटॉन का स्थानांतरण
(c) Transfer of electrons/ इलेक्ट्रॉनों का स्थानांतरण
(d) None of above/उपरोक्त में से कोई नहीं

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Sol. An oxidation-reduction (redox) reaction is a type of chemical reaction that involves a transfer of electrons between two species.

Q8. In thermal power stations carbon atoms undergo oxidation to form
थर्मल पावर स्टेशनों में किसका निर्माण करने के लिए कार्बन परमाणु ऑक्सीकरण से गुजरते हैं

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Sol. In thermal power stations carbon atoms undergo oxidation to form CO2.

(a) Oxidation/ ऑक्सीकरण
(b) Deduction/ निगमन
(c) Both/दोनों
(d) None/कोई नहीं

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Sol. Oxidation

(a) –2
(b) +2
(c) +6
(d) 8

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Sol. Let X is oxidation number of S,
Then X-8=-2

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