Question

What happens when hydrogen gas is passed over the heated copper oxide $(CuO)$?
(A) Black coating on the surface turns blue.
(B) Black coating on the surface turns brown.
(C) Black coating on the surface turns green.
(D) Black coating on the surface turns white.

Answer 1

Maker gas is a combination of combustible gases (primarily carbon monoxide and hydrogen) and non-flammable gases (for the most part nitrogen and carbon dioxide). Semi-water gas is a combination of water gas and maker gas made by passing a combination of air and steam through warmed coke.

Complete answer: In the event that hydrogen gas is disregarded warmed copper oxide $(CuO)$ , the dark covering on a superficial level turns earthy coloured as the converse response happens and copper is obtained. The substance response is as per the following:
$CuO + {H_2} \to Cu + {H_2}O$
The subsequent response is called oxidation-decrease response or redox response.
As during this response, the copper oxide is losing oxygen and is being decreased. The hydrogen is picking up oxygen and is being oxidised. In different words, one reactant gets oxidized while the difference gets decreased. At the point when hydrogen gas is ignored hot copper oxide, the dark covering on a superficial level turns earthy coloured as the opposite response happens and copper is obtained. Hydrogen gas (dihydrogen or atomic hydrogen) is profoundly combustible. The enthalpy of ignition is $- 286{KJ/mol}$. Hydrogen gas structures unstable combinations with air in fixations from $4 - 74\%$ and with chlorine at $5 - 95\%$ . The dangerous responses might be set off by flash, warmth, or daylight. The hydrogen autoignition temperature, the temperature of unconstrained start in air, is ${500^o}C$ $({932^o}F)$. The reactivity of ${H_2}$ is emphatically influenced by the presence of metal impetuses. Along these lines, while ${H_2}$ combusts promptly, combinations of ${H_2}$ and ${O_2}$ don't respond without an impetus.

ADDITIONAL INFORMATION:
Properties of Hydrogen are:
(i) Fire: Unadulterated hydrogen-oxygen blazes emanate bright light and with high oxygen blend are almost undetectable to the unaided eye, as shown by the weak crest of the Space Transport Fundamental Motor, contrasted with the profoundly obvious crest of a Space Transport Strong Rocket Supporter, which utilizes an ammonium perchlorate composite. The recognition of a consuming hydrogen break may require a fire locator; such holes can be extremely risky. Hydrogen flares in different conditions are blue, taking after blue flammable gas flames. The obliteration of the Hindenburg aircraft was a famous illustration of hydrogen ignition and the reason is as yet discussed. The obvious orange blazes in that occurrence were the consequence of a rich combination of hydrogen to oxygen joined with carbon mixes from the carrier skin.
(ii) Reactants: $H_2$ is moderately inert. The thermodynamic premise of this low reactivity is the solid H-H bond, with a bond separation energy of $435.7{KJ/mol}$. The active premise of the low reactivity is the nonpolar idea of ${H_2}$ and its powerless polarizability. It unexpectedly responds with chlorine and fluorine to shape hydrogen chloride and hydrogen fluoride, respectively.

Note: Hydrogen assumes an especially significant function in corrosive base responses on the grounds that most corrosive base responses include the trading of protons between solvent atoms. In ionic mixes, hydrogen can appear as a negative charge (i.e., anion) when it is known as a hydride, or as an emphatically charged (i.e., cation) species indicated by the image ${H^ + }$. The hydrogen cation is composed like made out of an exposed proton, however truly, hydrogen cations in ionic mixes are in every case more intricate.