question
in stratosphere , which of the following elements acts as a catalyst in degradation of ozone and release of molecular oxygen ?



 option 1)
 fe
 
 option 2)
 cl
 
 option 3)
 carbon
 
 option 4)
 oxygen
972
i. given:valency of carbon is 4valency of chlorine is 1by applying criss-cross method:formula: ccl4thus, the formula for carbon tetrachloride is ccl4.ii. given:valency of element x is 1valency of oxygen is 2by applying criss-cross method:formula: x2o oxygen in **Pure substance – ethyl alcohol, oxygen, carbon, distilled water mixture – blood, steel** on sapling its

oxidation:
cu --> cu^2+ + 2e^-

reduction:
o\_2 + 4e^- -->2o^2- we are being asked to classify the following reactions based on the following categories:combination/synthesis → multiple reactants combine to form a single productw/o change in oxidation numbersa + b → abdecomposition →reactant splits into multiple products with no change in oxidation numbersab → a + bcombustion reaction: reaction with oxygen that produces carbon dioxide and waterhydrocarbon + o2 → co2 + h2osingle displacement →single element displaces another element in a compoundab + c → ac + b[readmore]let’s analyze the given reactionsa. fe2(co3)2 (s) → fe2o3(s) + 2co2(g) break down of fe2(co3)2(s) to its component ions → decomposition reactionanswer: this is a decomposition reaction.b. 2 c6h11oh(l) + 17 o2(g) → 12co2 (g) + 12h2o(l) reaction with oxygen that produces carbon dioxide and water → combustion reactionanswer: this is a combustion reaction.c. p4o10(s) + 6h2o(l) → 4h3po4(aq) two or more substances combine to form a single compound → combination reactionanswer: this is a combination reaction.d. 2c(s) + mno2(s) → mn(s) + 2co(g) substitute one element for another element in a compound →single-displacement reaction answer: this is a single-displacement reactione. 2naclo3 (s) → 2nacl(s) + 3o2(g)break down of compound into its simpler substances → decomposition reactionanswer: this is a decomposition reaction answer: oxygen gas is responsible for combustion. combustion is characterized as a rapid exothermic reaction that releases a significant amount of energy in the form of heat and flames as combustion reactions that can spread through a suitable medium. combustion is the outcome of dynamic or time-dependent activities between atoms, molecules, radicals, and solid boundaries at the molecular level. for combustion to occur, three conditions must be met, which are there should be a combustible material. there should be a supporter of combustion. the combustible material is heated to the ignition temperature. the presence of fuel has a significant effect. the existence of oxygen or air. the ignition temperature is kept constant. a) he helium (he) is an element by itself. he atom can only exhibit dispersion forces.b) hclh          1a                   1 × 1 e– = 1 e–cl         7a                   1 × 7 e– = 7 e–   total: 8 valence e–[readmore]cl is more electronegative than h, so hcl is a polar covalent compound. hcl exhibits dipole-dipole interaction.c) h2oh          1a                   1 × 2 e– = 2 e–o          6a                   1 × 6 e– = 6 e–   total: 8 valence e– since hydrogen is bonded directly to oxygen.h2o exhibits hydrogen bonding.d) cl2cl         7a                   1 × 7 e– = 14 valence e–composed of the same atom. there's no electronegativity difference.cl2 can only exhibit dispersion forces. there are 3 types of hybridisation for carbon in organic compounds, sp, sp2 and sp3 depending on the number of sigma and pi bonds between the carbon atoms. more the ‘s’ character more is the electronegativity of the carbon as ‘s’ orbitals are closer to the nucleus, hence electrons held more closely. carbon monoxide combines with the haemoglobin of our blood. it reduces the oxygen carrying capacity of blood. <p>concepts and reason</p>
<p>the concept used to solve this problem is the formal charge calculation of the oxygen atoms present in the ozone molecule.</p>
<p>fundamentals</p>
<p>a charge that is assigned to an atom, which is present in the molecule, is represented as a formal charge. in two bonded atoms, a formal charge assumes that the electrons are equally shared between them. the formal charge is calculated using the following formula:</p>
<p>formal charge \(=\mathrm{v}-\mathrm{n}-\frac{\mathrm{b}}{2}\)</p>
<p>here, \(\mathrm{v}\) is the number of valence electrons, \(\mathrm{n}\) is the number of non-bonding electrons and \(\mathrm{b}\) is the number of bonding electrons.</p>
<p> </p>
<p>the structure is as follows:</p>
<p>calculate the formal charge for the circled oxygen in ozone molecule as follows:</p>
<p><img src="https://img.wizedu.com/images/5af6d1f54822b4dfb8fe89d91ef2011c5fe3020815aa4.png" alt="" width="88" /></p>
<p>formal charge \(=\mathrm{v}-\mathrm{n}-\frac{\mathrm{b}}{2}\)</p>
<p>\(\begin{aligned}=& 6-6-\frac{2}{2} \\ &=-1 \end{aligned}\)</p>
<p>explanation | common mistakes | hint for next step</p>
<p>the marked oxygen atom has 6 valence electrons. it contains 6 non-bonding electrons. the marked oxygen atom is bonded with one oxygen atom. therefore, the bonding electron of oxygen is \(2 .\) substitute the values in a formal charge formula to determine the formal charge of oxygen (marked).</p>
<p> </p>
<p>the structure is as follows:</p>
<p><img src="https://img.wizedu.com/images/39493056a8515708b79350d1976e17b35fe30216f0473.png" alt="" width="88" /></p>
<p>calculate the formal charge for the circled oxygen in ozone molecule as follows:</p>
<p>formal charge \(=\mathrm{v}-\mathrm{n}-\frac{\mathrm{b}}{2}\)</p>
<p>\(=6-2-\frac{6}{2}\)</p>
<p>\(=+1\)</p>
<p>explanation | common mistakes | hint for next step</p>
<p>the oxygen atom in the middle has 6 valence electrons and has 2 non-bonding electrons. the central oxygen atom is bonded with 1 double bond and 1 single bond. so, there is a total of 3 bonds containing 6 electrons (bonding electrons). the formal charge of the middle oxygen atom can be determined by substituting the values in a formal charge formula.</p>
<p> </p>
<p>the structure is as follows:</p>
<p><img src="https://img.wizedu.com/images/b1122ce7723aa4ab1f9ae5c9e457299e5fe3022ca77a5.png" alt="" width="88" /></p>
<p>calculate the formal charge for the circled oxygen in ozone molecule as follows:</p>
<p>formal charge \(=\mathrm{v}-\mathrm{n}-\frac{\mathrm{b}}{2}\)</p>
<p>\(=6-4-\frac{4}{2}\)</p>
<p>\(=0\)</p>
<p>the formal charge of each oxygen atom in \(\mathrm{o}\_{3}\) molecule are labeled as follows:</p>
<p><img src="https://img.wizedu.com/images/1de5ee227194f6d8c7fb9fb0e76160f25fe3024117fde.png" alt="" width="120" /></p>
<p>the oxygen atom present on the right side contains 6 valence electrons which have 2 non-bonded electrons. the marked oxygen is bonded with 1 double bond with a central oxygen atom. so, the number of bonding electrons is \(4 .\) the formal charge of the corner oxygen atom (right corner) can be determined by substituting the values in the formal charge formula.</p>
<p>the formal charge of each oxygen atom in \(\mathrm{o}\_{3}\) molecule are labeled as follows:</p>
<p><img src="https://img.wizedu.com/images/1de5ee227194f6d8c7fb9fb0e76160f25fe3024117fde.png" alt="" width="120" /></p>