Mix Examples - Metals and Non-metals Questions in English

(B) The apparatus used for the electrolysis of water is called a $Voltameter$ (specifically a Hofmann Voltameter).
It consists of three joined upright cylinders,usually made of glass.
The central cylinder is open at the top to allow for the addition of water and an electrolyte (to increase conductivity,as pure water is a poor conductor).
Electrodes are placed at the bottom of the two side cylinders to collect the hydrogen and oxygen gases produced during the process.
Note: $A$ $Voltmeter$ is an instrument used to measure electrical potential difference,whereas a $Voltameter$ is an electrochemical cell used to perform electrolysis.

(C) Dihydrogen gas $(H_2)$ is a neutral gas.
Litmus paper is an acid-base indicator used to detect the presence of acidic or basic substances.
Since $H_2$ gas is neither acidic nor basic in nature,it does not change the color of either red or blue litmus paper.
Therefore,it has no effect on litmus paper.

(D) $1$. $H_2$ gas acts as a strong reducing agent because it can remove oxygen from metal oxides.
$2$. $H_2$ gas is highly combustible and burns with a pale blue flame.
$3$. $H_2$ gas is neutral in nature,meaning it does not change the color of blue or red litmus paper.
$4$. $H_2$ gas is $NOT$ a supporter of combustion; it is combustible itself. Oxygen $(O_2)$ is the gas that supports combustion. Therefore,statement $D$ is incorrect.

(A) When copper oxide $(CuO)$ is heated in the presence of dihydrogen gas $(H_2)$, a redox reaction occurs.
In this reaction, $CuO$ loses oxygen to form copper metal $(Cu)$, which is a reduction process.
Simultaneously, $H_2$ gains oxygen to form water $(H_2O)$, which is an oxidation process.
The chemical equation for this reaction is: $CuO(s) + H_2(g) \xrightarrow{\Delta} Cu(s) + H_2O(g)$.
Thus, copper metal is obtained as a product.

(A) The reaction between hydrogen $(H_{2})$ and chlorine $(Cl_{2})$ is a photochemical reaction.
In the presence of sunlight,these two gases react to form hydrogen chloride $(HCl)$ gas.
The chemical equation for this reaction is: $H_{2}(g) + Cl_{2}(g) \xrightarrow{\text{sunlight}} 2HCl(g)$.
This reaction does not occur in the dark and requires the energy provided by sunlight to break the bonds in the reactant molecules.

(B) When $H_2$ and $Cl_2$ gases react,they form hydrogen chloride gas $(HCl)$.
In the presence of moisture or when the gas is released into the atmosphere,$HCl$ gas reacts with water vapor to form dense white fumes of hydrochloric acid droplets.
Therefore,the white fumes observed are of hydrogen chloride $(HCl)$.

(C) The process of converting vegetable oil into vegetable ghee (solid fat) is known as hydrogenation.
In this chemical reaction,hydrogen gas is added to unsaturated vegetable oils in the presence of a catalyst,typically $Nickel$ $(Ni)$,at a specific temperature.
The $Nickel$ catalyst facilitates the addition of hydrogen across the double bonds of the unsaturated fatty acids present in the oil,converting them into saturated fats,which are solid at room temperature.

(C) The process of converting vegetable oils (which contain unsaturated fatty acids) into vegetable ghee (which contains saturated fatty acids) is known as $Hydrogenation$.
In this process,vegetable oil is reacted with hydrogen gas in the presence of a catalyst,such as nickel $(Ni)$,at a specific temperature.
This addition of hydrogen across the double bonds of the unsaturated fats converts them into saturated fats,resulting in a solid or semi-solid state known as vegetable ghee.

(B) The process of converting vegetable oils into vegetable ghee (vanaspati ghee) is known as hydrogenation. In this process,unsaturated vegetable oils are reacted with $H_2$ (dihydrogen) gas in the presence of a catalyst,such as nickel $(Ni)$,at a specific temperature and pressure. This reaction converts the unsaturated fats into saturated fats,resulting in a solid or semi-solid state known as vegetable ghee.

(D) The calorific value of a fuel is the amount of heat energy produced by the complete combustion of $1 \ kg$ of that fuel.
- The calorific value of $CH_4$ (Methane) is approximately $50,000 \ kJ/kg$.
- The calorific value of $C_4H_{10}$ (Butane) is approximately $50,000 \ kJ/kg$.
- The calorific value of Water gas $(CO + H_2)$ is approximately $15,000 \ kJ/kg$.
- The calorific value of $H_2$ (Dihydrogen gas) is approximately $150,000 \ kJ/kg$.
Therefore,$H_2$ (Dihydrogen gas) has the highest calorific value among the given options.

(C) Dihydrogen $(H_2)$ is considered a potential major energy source for the future.
$1$. It is an environmentally friendly fuel because its combustion produces only water $(H_2O)$ as a byproduct,resulting in zero carbon emissions.
$2$. It has a very high energy content per unit mass compared to conventional fossil fuels.
$3$. As fossil fuel reserves are depleting and causing climate change,$H_2$ is being researched as a sustainable alternative.

(A) Hydrogen is the first element in the periodic table with an atomic number of $1$. It is placed at the top of Group $1$ in the modern periodic table.

(B) The industrial production of ammonia $(NH_3)$ is achieved through the Haber process. This process was developed by the German chemist Fritz Haber in the early $20^{th}$ century. In this process,nitrogen gas $(N_2)$ and hydrogen gas $(H_2)$ are reacted under high pressure and temperature in the presence of an iron catalyst to produce ammonia.

(C) Ammonia $(NH_3)$ is manufactured on an industrial scale using the Haber's process.
In this process, nitrogen gas $(N_2)$ and hydrogen gas $(H_2)$ are reacted in a $1:3$ ratio at high temperature and high pressure in the presence of an iron catalyst.
The chemical reaction is: $N_2(g) + 3H_2(g) \rightleftharpoons 2NH_3(g)$.

(D) The chemical equation for the Haber's process is: $N_2(g) + 3H_2(g) \rightleftharpoons 2NH_3(g)$.
According to the stoichiometry of the reaction, $1$ mole of dinitrogen $(N_2)$ reacts with $3$ moles of dihydrogen $(H_2)$.
Therefore, the ratio of dihydrogen gas to dinitrogen gas is $3:1$.

(A) Substances that are added to a catalyst to increase its activity or efficiency are known as $Promoters$ (or $Activators$).
For example,in the $Haber$ process for the manufacture of $NH_3$,$Fe$ acts as a catalyst,while $Mo$ acts as a promoter to increase the efficiency of $Fe$.

(C) Ammonia $(NH_3)$ is a polar molecule that can form hydrogen bonds with water molecules.
Due to this ability to form strong hydrogen bonds,ammonia is extremely soluble in water.
In contrast,gases like $O_2$ are non-polar and have very low solubility in water.
Therefore,$NH_3$ is the correct answer.

(B) When ammonia gas $(NH_3)$ reacts with hydrogen chloride gas $(HCl)$,they undergo a chemical reaction to form solid ammonium chloride $(NH_4Cl)$.
The balanced chemical equation for this reaction is:
$NH_3(g) + HCl(g) \rightarrow NH_4Cl(s)$
This reaction is characterized by the formation of dense white fumes of ammonium chloride.

(B) When a glass rod dipped in concentrated hydrochloric acid $(HCl)$ is brought near ammonia gas $(NH_3)$,they react to form ammonium chloride $(NH_4Cl)$ solid particles.
The chemical equation for this reaction is: $NH_3(g) + HCl(g) \rightarrow NH_4Cl(s)$.
These solid particles of ammonium chloride appear as dense white fumes.

(B) The gas $NO_2$ (Nitrogen dioxide) is a reddish-brown gas.
$NO$ (Nitric oxide) is a colorless gas.
$N_2O$ (Nitrous oxide) is a colorless gas.
$SO_2$ (Sulfur dioxide) is a colorless gas.
Therefore,the correct option is $B$.

(D) Nitric acid is a strong mineral acid with the chemical formula $HNO_{3}$.
It is a colorless,fuming liquid that is highly corrosive and toxic.
In the given options,$HNO_{2}$ represents nitrous acid,$NH_{4}Cl$ represents ammonium chloride,and $H_{2}NO_{3}$ is not a standard chemical formula for a stable acid.

(C) The industrial production of nitric acid $(HNO_{3})$ is primarily carried out using the $Ostwald's$ process.
In this process,ammonia $(NH_{3})$ is catalytically oxidized to nitric oxide $(NO)$ in the presence of platinum-rhodium gauze as a catalyst.
The nitric oxide is then oxidized to nitrogen dioxide $(NO_{2})$,which is subsequently absorbed in water to produce nitric acid $(HNO_{3})$.
Therefore,the correct option is $C$.

(D) Ammonium hydroxide $(NH_4OH)$ is a solution of ammonia $(NH_3)$ in water.
It dissociates only partially in an aqueous solution to produce ammonium ions $(NH_4^+)$ and hydroxide ions $(OH^-)$.
Because it does not ionize completely,it is classified as a weak base.

(B) When an aqueous solution of ammonia $(NH_{4}OH)$ is added to a solution of cupric sulfate $(CuSO_{4})$,a pale blue precipitate of copper$(II)$ hydroxide $(Cu(OH)_{2})$ is formed initially.
The chemical reaction is: $CuSO_{4}(aq) + 2NH_{4}OH(aq) \rightarrow Cu(OH)_{2}(s) + (NH_{4})_{2}SO_{4}(aq)$.
Upon adding excess ammonia,this precipitate dissolves to form a deep blue complex,tetraamminecopper$(II)$ sulfate.

(D) Para aminobenzoic acid $(PABA)$ is a chemical compound that can be synthesized using ammonia as a precursor in certain industrial chemical processes.
$PABA$ is used in the pharmaceutical industry for the production of various medicines,including local anesthetics like benzocaine and procaine.
While ammonium nitrate,diammonium phosphate,and ammonium sulphate are nitrogenous compounds,they are primarily used as fertilizers rather than as medicinal ingredients.

(B) Sulphur is a non-metal element with the chemical symbol $S$.
Its atomic number is $16$,which represents the number of protons in its nucleus.
Therefore,the correct option is $B$.

(C) The atomic number of sulphur $(S)$ is $16$.
Electronic configuration is determined by filling electrons in shells $(K, L, M, ...)$ according to the rule $2n^2$.
For $n=1$ ($K$ shell): $2(1)^2 = 2$ electrons.
For $n=2$ ($L$ shell): $2(2)^2 = 8$ electrons.
For $n=3$ ($M$ shell): The remaining electrons are $16 - (2 + 8) = 6$ electrons.
Thus,the electronic configuration of sulphur is $2, 8, 6$.

(A) The mineral of sulfur among the given options is Galena $(PbS)$.
Galena is the primary ore of lead and is chemically known as lead sulfide.
Silica is silicon dioxide $(SiO_2)$.
Horn silver is silver chloride $(AgCl)$.
Siderite is iron carbonate $(FeCO_3)$.

(C) Sulphur is extracted from underground deposits in the earth's crust using the $Frasch$ process.
In this method,superheated water $(170 \ ^\circ C)$ is pumped into the sulphur deposit to melt it.
The molten sulphur is then forced to the surface by compressed air.
$Contact$ process is used for the manufacture of sulphuric acid.
$Haber's$ process is used for the production of ammonia.
$Oswald's$ process is used for the production of nitric acid.

(D) Sulfur exists in nature as a polyatomic molecule.
Specifically,a single molecule of sulfur consists of $8$ sulfur atoms arranged in a puckered ring structure,commonly known as $S_8$.

(B) Rhombic sulphur,also known as $\alpha$-sulphur,is the most stable allotrope of sulphur at room temperature.
It is formed by evaporating a solution of roll sulphur in $CS_2$.
The crystals of rhombic sulphur have an octahedral shape.

(A) Monoclinic sulphur, also known as $\beta$-sulphur, is an allotrope of sulphur.
It is prepared by melting rhombic sulphur in a dish and cooling it until a crust is formed.
Two holes are made in the crust and the remaining liquid is poured out.
Upon removing the crust, colourless needle-shaped crystals of monoclinic sulphur are formed.
Therefore, the shape of monoclinic sulphur is needle-shaped.

(B) Sulphur is a non-polar covalent molecule. According to the principle of 'like dissolves like',it is insoluble in polar solvents like water but soluble in non-polar organic solvents. Carbon disulphide $(CS_2)$ is a well-known non-polar organic solvent in which sulphur readily dissolves.

(A) Sulfur is a non-metal that exists in various allotropic forms,most commonly as rhombic sulfur $(S_8)$.
The melting point of sulfur is approximately $388 \ K$ $(115 \ ^\circ C)$.
Therefore,the correct option is $A$.

(C) Vulcanization is a chemical process used to improve the physical properties of natural rubber.
In this process,natural rubber is heated with $S$ (sulfur) at a temperature range of $140^{\circ}C$ to $160^{\circ}C$.
The addition of sulfur creates cross-links between the polymer chains of rubber,which makes the rubber harder,more durable,and resistant to heat and wear.
Therefore,the correct non-metal used is sulfur.

(D) Sulfur is widely used in the manufacture of sulfuric acid $(H_2SO_4)$,in the vulcanization of rubber,in the preparation of skin ointments (antiseptic properties),and in the production of fireworks and gunpowder. However,sulfur is not used in the manufacture of nitric acid $(HNO_3)$. Nitric acid is primarily produced by the Ostwald process using ammonia $(NH_3)$ and oxygen $(O_2)$.

(B) Acid rain is primarily caused by the emission of sulfur dioxide $(SO_2)$ and nitrogen oxides $(NO_x)$.
When these gases are released into the atmosphere,they react with water vapor,oxygen,and other chemicals to form sulfuric acid $(H_2SO_4)$ and nitric acid $(HNO_3)$.
These acids then fall to the ground with rain,causing environmental damage.
Among the given options,sulfur dioxide $(SO_2)$ is the primary gas responsible for acid rain.

(C) Sulfur dioxide $(SO_2)$ is a colorless gas with a pungent,irritating smell that resembles the scent of a burnt match. When inhaled,it reacts with the moisture in the respiratory tract to form sulfurous acid,which causes severe irritation,choking,and coughing. Among the given options,sulfur is the element that forms this gas upon combustion.

(C) When sulfur dioxide $(SO_2)$ gas is passed through lime water (calcium hydroxide,$Ca(OH)_2$),it reacts to form calcium sulfite $(CaSO_3)$ and water.
The chemical equation is: $Ca(OH)_2(aq) + SO_2(g) \rightarrow CaSO_3(s) + H_2O(l)$.
Calcium sulfite $(CaSO_3)$ is an insoluble white precipitate,which makes the lime water appear milky.

(D) The reaction for the formation of sulphur trioxide $(SO_3)$ from sulphur dioxide $(SO_2)$ is a key step in the Contact Process for the manufacture of sulphuric acid.
The chemical equation is: $2SO_2(g) + O_2(g) \rightleftharpoons 2SO_3(g)$.
This reaction is carried out at high temperatures (approximately $450^{\circ}C$) in the presence of $V_2O_5$ (Vanadium pentoxide) as a catalyst to increase the rate of reaction and yield.
Therefore,the correct catalyst is Vanadium pentoxide.

(C) Potassium dichromate $(K_2Cr_2O_7)$ is a strong oxidizing agent. In an aqueous solution,the dichromate ion $(Cr_2O_7^{2-})$ exists in equilibrium with the chromate ion $(CrO_4^{2-})$. The potassium dichromate solution is characteristically orange in color due to the presence of the dichromate ion.

(A) When sulfur dioxide $(SO_2)$ gas is passed through an acidic potassium dichromate $(K_2Cr_2O_7)$ solution,it acts as a reducing agent.
The orange-colored dichromate ion $(Cr_2O_7^{2-})$ is reduced to the green-colored chromium$(III)$ ion $(Cr^{3+})$.
The chemical reaction is: $K_2Cr_2O_7 + 3SO_2 + H_2SO_4 \rightarrow K_2SO_4 + Cr_2(SO_4)_3 + H_2O$.
Due to the formation of chromium$(III)$ sulfate,the solution turns green.

(C) Potassium dichromate is an inorganic chemical reagent with the formula $K_{2}Cr_{2}O_{7}$.
It is a common oxidizing agent used in various laboratory and industrial applications.
In this compound,the dichromate ion is $Cr_{2}O_{7}^{2-}$,which balances with two potassium ions $(K^{+})$ to form a neutral compound.

(A) When boiling sulfur reacts with dihydrogen gas $(H_{2})$,it forms hydrogen sulfide gas $(H_{2}S)$.
The chemical equation for this reaction is:
$S(l) + H_{2}(g) \xrightarrow{\Delta} H_{2}S(g)$
Here,sulfur is in the liquid state (boiling) and reacts with hydrogen gas to produce hydrogen sulfide.

(C) The chemical formula of sodium sulfite is determined by the valency of its constituent ions.
Sodium $(Na)$ has a valency of $+1$.
The sulfite ion $(SO_{3}^{2-})$ has a valency of $-2$.
To balance the charges,two sodium ions are required for every one sulfite ion.
Therefore,the formula is $Na_{2}SO_{3}$.

(D) The chemical reaction is: $SO_{2} + 2H_{2}S \rightarrow 3S + 2H_{2}O$.
In this reaction,$SO_{2}$ oxidizes $H_{2}S$ to $S$ and itself gets reduced to $S$.
Since $SO_{2}$ causes the oxidation of $H_{2}S$,it acts as an oxidizing agent.
Option $D$ states that it acts as a weak bleaching agent. While $SO_{2}$ is a bleaching agent,this property is not relevant to the chemical reaction described in the question. Therefore,the statement in option $D$ is incorrect in the context of this specific reaction.

(B) When sulfur dioxide $(SO_2)$ reacts with an acidic solution of potassium dichromate $(K_2Cr_2O_7)$,the sulfur dioxide acts as a reducing agent.
In this reaction,the oxidation state of sulfur in $SO_2$ increases from $+4$ to $+6$ (in $SO_4^{2-}$),meaning $SO_2$ undergoes oxidation.
Simultaneously,the chromium in $K_2Cr_2O_7$ is reduced from $+6$ to $+3$ $(Cr^{3+})$.
Therefore,the overall process involves the oxidation of sulfur dioxide by potassium dichromate.

(B) Sulfur dioxide $(SO_{2})$ acts as a mild bleaching agent due to its reducing property.
It bleaches colored matter by the removal of oxygen (reduction).
This bleaching effect is temporary because the bleached matter regains its color upon exposure to air due to atmospheric oxidation.

(C) Sulfur dioxide $(SO_{2})$ is a gas that is widely used as a food preservative and antimicrobial agent.
It inhibits the growth of bacteria,molds,and yeasts by interfering with their metabolic processes and enzyme activity.
Therefore,$SO_{2}$ is effective in preventing bacterial growth in various food products.

(A) The $Contact$ process is the industrial method used for the production of sulphuric acid $(H_2SO_4)$.
In this process,sulphur dioxide $(SO_2)$ is oxidized to sulphur trioxide $(SO_3)$ in the presence of a vanadium pentoxide $(V_2O_5)$ catalyst,which is then absorbed in concentrated sulphuric acid to form oleum $(H_2S_2O_7)$,followed by dilution with water.
$Haber's$ process is used for the synthesis of ammonia $(NH_3)$.
$Oswald$ method is used for the production of nitric acid $(HNO_3)$.
$Frasch$ method is used for the extraction of elemental sulphur from underground deposits.