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This section includes 7 InterviewSolutions, each offering curated multiple-choice questions to sharpen your Current Affairs knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
The following is an extract from 'Metals in the service of man,Alexander andStreet/ Pelican 1976':Alumina (aluminium oxide) has a very high melting point of over 2050°C so that it cannot readily be liquified. However, conversion of aluminato aluminium and oxygen, by electrolysis, can occur when it is dissolvedin some other substance".(i) Which solution is used to react with bauxite in obtaining purealumina?(ii) Write three chemical reactions involved in Bayer's process.(iii) Name the impurities associated with ore and how are theyremoved?(iv) Carbon can reduce lead oxide but not aluminium oxide. Why?(V) Name the element which serves as both the anode andcathode in the extraction of aluminium.(vi) Write the equation for the reaction that occurs at the cathodeand anode during the extraction of aluminium by clectrolysis.(vii) Name the other ore of aluminium added in electrolyte. Whyis it added(viii) Why is anode replaced from time to time?(ix) Powdered coke is sprinkled on the surface of the electrolyticmixture. Give reason.Name an alloy of Aluminium which is used to make aircraftbody and why? |
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Answer» Answer: the service of man, Alexander and Street/ Pelican 1976': Alumina (ALUMINIUM oxide) has a very high MELTING point of over 2050° C so that it cannot readily be liquified. However, conversion of alumina to aluminium and oxygen, by electrolysis, can occur when it is dissolved in some other substance". (i) Which solution is USED to react with bauxite in obtaining pure alumina? (ii) Write three chemical reactions to be a good human being and electricity and WATER and electricity and water and electricity |
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| 2. |
Two flask of equal volumes are evacuated. One is filled with gas A and other with gas B at the sametemperature and pressure. The weight of gas B was found to be 0.8 gm while the weight of gas A is foundto be 1.4 gm. The weight of one molecule of B is -(1) 1.4 times as that of A(2) 0.4 times as that of A(3) 0.57 times as that of A(4) 0.8 times as that of A |
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Answer» Answer: 1) 1.4 TIMES AS THAT OF A Explanation: BECAUSE BOTH ARE SAME |
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| 3. |
AboConstant pressure, the VolumegassisGoo sool at book.Volume of the gasegas ichaWhat is the volume oftemparature is increased to booke? |
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| 4. |
Name four characteristics which are improved in natura l rubber by the process of vulcanization. |
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Answer» Answer: vulcanization is a chemical process in which the RUBBER is heated by sulphur accelerator and activator at 140 _160°C the process involves the formation of cross links between long rubber molecules so as to ACHIEVE improved elasticity resilience and TENSILE strength VISCOSITY and hardness and whether RESISTANCE |
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| 6. |
A solid ab crystallises in nacl structure the anion b form fcc lattice while the cation a occupy all the octahedral holes if all the particle as shown are removed then formula of solid is |
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Answer» Answer: show the STRUCTURE. if you don't show it, your QUESTION cannot be ANSWERED . ab ---> a+ + B- |
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| 7. |
|5. Gold metal crystallizes in a face -centred cubicunit cell (fcc). Determine the density of gold.(Atomic mass of gold =179 u, atomic radius =0.144nm,| N = 6.022x10 23 mol-' )(গ’ল্ড ধাতুৱে পৃষ্ঠকেন্দ্রিক ঘনকীয় (fcc) একক কোষ গঠনকৰে। গ’ল্ডৰ ঘনত্ব নির্ণয় কৰা। (গ’ল্ডৰ পাৰমাণৱিক ভৰ |=179 u, পাৰমাণৱিক ব্যাসার্ধ =0.144nm, |
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Answer» Answer: ✨ ✨༺ H E Y 彡M A T E ࿐✨ ✨ Here Is Your Answer, Hope It helps ___________________________________________ Answer:-Here Z= 4 (SINCE it's FCC) M= 197 r = 0.144 a = ? THEREFORE, Step-I. Calculate of edge length of unit cell. a=2√2r a=2√2 × 0.144 nm a=407.23 pm (unit converted)
Step-II. Calculation of density of unit cell. Density=Z×M/a^3×No×10^-30
Density =4×197/(407.23) ^3 × 6.022 × 10^23 × 10^-30 Density= 19.38 g/cm^3 ---------------------------------------------------------------------------------- Extra - Here, (No)is Avogadro Number (a^3) is a CUBE [for clarification so U won't have doubt ] I saw the previous answers of this question on Brainly which were totally rubish, so I REPORTED them and had the moderators remove them, it's a request to not waste a person's time and effort by giving trash answers just for points. ___________________________________________ , (づ￣ ³￣)づ |
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| 8. |
Pls explain briefly about periodic tabletricks to learn aualperiodic table |
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Answer» Answer: these are the trick to learn first 20 ELEMENTS Explanation: Happy Henry Lives Beside Boron Cottage, Near Our Friend Nelly Nancy MgAllen. Silly PATRICK Stays Close. Arthur Kisses Carrie. Here He Lies BENEATH Bed Clothes, Nothing On, FEELING Nervous, Naughty Margret Always Sighs, ” Please Stop Clowning Around ” (18 elements) How He Likes Bear By Cups Not Overflowing. Although Science Presents Some Clues, Are Kittens Cats? Explanation: Happy. – H Hydrogen Henry – He Helium Lives – Li Lithium Beside – Be Beryllium Born – B Boron Cottage – C Carbon Near – N Nitrogen Our – O Oxygen Friend – F Fluorine. Nelly – Ne Neon Nancy – Na Sodium Mg – Mg Magnesium Allen – AL Aluminum Silly – Si Silicon Patrick – P Phosphorus Stays – S Sulphur Close – Cl Chlorine Arthur – Ar Argon Kisses – K Potassium Carrie – Ca Calcium |
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| 9. |
Explain the saturation state in adsorption isotherm for 2 marks |
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Answer» hlo mate here is UR ans..... Adsorption ISOTHERM is a curve that expresses the variation in the amount of gas adsorbed by the ADSORBENT with pressure at CONSTANT temperature...hope this hepls uh dear.... pls mark as brainliest ... |
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| 11. |
Copper crystal has a fcc lattice structure. Atomic radius of Cu atom is 128 pm. Calculate thedensity of Cu (Atomic mass - 63.5) Hint: Atomic radius = r |
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| 12. |
A sample of carbon contains 95% by mole C¹² and 5% C¹⁴ isotopes. The average number of neutron per atom is? |
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Answer» h5jtdkydnndiydo6foyffouf |
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| 13. |
The solubility of AgCl is m g dm^-3.If 1 mole of AgCl weighs M g the solubility product of AgCl will be A) m^2/M B) m/M^2 C) m^2/M^2 D) m^2M^2 |
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Answer» Iᴛ sᴇᴇᴍᴇᴅ ᴛʜᴀᴛ ʙʀᴀɪɴʟʏ ᴍᴏᴅᴇʀᴀᴛᴏʀs ᴅᴏᴇsɴᴏᴛ ʟɪᴋᴇ ᴍʏ ᴀɴsᴡᴇʀ sᴏ ᴛʜᴀᴛ ɪ ʜᴀᴅ ᴛᴏ ᴛᴀᴋᴇ sᴄʀᴇᴇɴsʜᴏᴛ ᴏғ ɪᴛ |
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| 14. |
Name the two substances that have differrnt colours in acidic and basic solution ?what is the general name for such substances |
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| 15. |
♡CHEMICAL PROPERTIES OF GLUCOSE♡GOOD MORNING MY BESTIE DON'T SPAM HERE ❤ |
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Answer» Good morning GLUCOSE Molecular formula Is C6H12O6 Glucose is ALSO known as simple sugar. It is the most abundant molecular formula for carbohydrates containing 6 CARBON atom. It is an organic compound. There are TWO types of glucose ITS MOLAR MASS IS 180.156 g/mol It's melting point is 146`C |
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| 16. |
Electronic configuration of positive ions in Mno2 is. |
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Answer» Explanation: Mn^+ -> [Ar]4s²3d4(cation)- positive O^2- -> [He]2s²2p⁶(ANION) - negative |
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| 17. |
Which of the following will give basic aqueous solution?A) sodium formateB) ammonium chlorideC) sodium sulphateD) potassium chloride |
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Answer» sodium formate |
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| 18. |
Sodium has a bcc structure with cell edgelengh 422.5 pm.Calculate its density (Atomic mass =23) |
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Answer» bccstructure has a SODIUM |
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| 19. |
A substance when treated with dil.sulphuric acids gives a colourless gas which turns limewater milky .Name that substance |
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Answer» EX: Na2CO3 Explanation: |
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| 20. |
Give the location and the main funtion of each of the following cell components |
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Answer» a)HELPS in SEPARATION of INNER and external environment of the cell.It is a selectively permeable ... More 44 votes a)protect cell from injuryb)compact structure of dnac)to PRODUCE proteinsd)to control ... More |
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| 21. |
4) Colour, Hardness, Melting points. Boiling points. Odour. Ena) Physical propertiesb) Chemical propertiesc) Both (a) and (b)d) Example of chemical reactions |
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| 22. |
Food manufacture pack fried foods with which gas to prevent oxidation of fat |
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Answer» Answer: FRIED foods are rarely associated with “healthy” foods. They remain, however, among the most popular foods, not just in the United STATES, but globally as well. The basic frying process involves simultaneous complex and dynamic events. The frying medium (fat or oil) is heated to high temperatures, typically 335– 400°F, and foods containing VARIOUS mixes of proteins, carbohydrates, their own lipid material, water, seasonings, salt, etc., cause a nearly infinite number of potential chemical reactions. These reactions, in turn, result in various end products, such as polar compounds and polymers, not found in either fresh oil or unfried foods. The other obvious issue with fried foods is in the relatively high-fat/oil content and with this, the high caloric content of most fried foods. Thus, when attempting to compile a list of current and future nutritional ISSUES related to fried foods, the most logical place to start is the ever-increasing concern about obesity. Fried foods and sweetened, carbonated beverages are the most frequently referenced foods relating to this subject. The biggest issue with fried foods is the high PERCENTAGE of fat in these types of foods.Plz mark as brainliest.. |
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| 23. |
Explain the following equation x + y gives a+b |
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Answer» I am not SURE about WUT U have asked, so...... FOLLOW me please... |
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| 24. |
Please answer this question,it's urgent---------- |
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Answer» 2)As the IONIC compounds are BOUND up of ion and have a strong bonds in itself .Hence,it require high MELTING POINT 2 be separated. i hope u will like it! |
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| 25. |
What is the symbol for s.i. unit of mole? how is the defined |
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Answer» Answer: MOLE is unitless. The S.I. UNIT of molar MASS is g/mol.. One mole of an substance is 6.22×10^23 PARTICLES of the substance.. Mark as brainliest PLEASE... |
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| 26. |
What is the molar mass of copper in kg mol ^-1 |
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Answer» cucl2 Explanation: |
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| 27. |
The most abundantly occurring element on the earth is |
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Answer» The mass-abundance of the nine most abundant elements in the Earth's crust is APPROXIMATELY: OXYGEN 46%, silicon 28%, ALUMINUM 8.3%, iron 5.6%, CALCIUM 4.2%, sodium 2.5%, magnesium 2.4%, potassium 2.0%, and titanium 0.61 |
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| 28. |
If atom is made up op electrons and protons in equal amount but electon have negative charge whereas proton has positive so why dont they attract each other inside a shell |
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Answer» because opposite charge repells each other. Explanation: you take a magnet a TWO manget take north and south pole and TRY to COMBINE then it will repells due to opposite charge. |
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| 29. |
3) Rewrite the following equations in terms of symbols andformulae .Balance the equations.(4)a) White precipitate of silver chloride is formed on adding asolution of sodium chloride to silver nitrate solution.b) Methane (CH2) burns in air to give carbon dioxide, waterand heat is evolvedc) Potassium chlorate on heating decomposes to givepotassium chloride and oxygen gasd) carbon dioxide when passed through lime water gives aprecipitate of calcium carbonate. |
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| 30. |
What happen when ammonia is reacted with blue vitrol? |
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| 31. |
Plz give explanation of activity 2.1 of lesson 2 acid ,base and salt in chemistry class 10. |
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Answer» Answer:Explanation:Process: 1) First of all, assemble the following SAMPLES from the ... More 7 votes Answer:table 2.1Explanation:Sample Solution RED LITMUS BLUE Litmus Phenolphthalein ... More |
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| 32. |
What is chemistry......??? |
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Answer» Answer: Chemistry is the scientific discipline involved with ELEMENTS and compounds composed of atoms, MOLECULES and ions: their composition, structure, PROPERTIES, behavior and the changes they undergo during a REACTION with other SUBSTANCES |
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| 33. |
Acidic,basic,and neutral salts of sodium chloride |
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Answer» Explanation: WHENEVER an acid and a base react, they have the potential to FORM a salt. For example, when SODIUM hydroxide reacts with hydrochloric acid in water, they form sodium chloride, a salt. ... When a strong base reacts with a strong acid, a neutral salt is FORMED. |
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| 34. |
How does our immune system protect us from viral infections? |
Answer» The immune system has a vital ROLE: It protects your body from harmful substances, germs and cell changes that could make you ill. It is made up of various ORGANS, cells and proteins.As LONG as your immune system is running smoothly, you don’t notice that it’s there. But if it stops working properly – because it’s weak or can't fight particularly aggressive germs – you get ill. Germs that your body has never encountered before are also likely to make you ill. Some germs will only make you ill the first time you come into contact with them. These include childhood diseases LIKE chickenpox. |
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| 35. |
Galculate the molar mass of the following compounds.i)Urea (CO(NH2)2ii)Acetone [CH,COCH3) iii)Boric acid [H_BO3) iv) Sulphuric acid [H2SO4] |
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| 36. |
Write a structure for each of the compounds listed. Explain why the name given is incorrect, and give a correct name in each case (20 marks) a.1-methylbutane b.1,1,3-trimethylhexane c.5-octyne d.2-ethyl-1-propanol e.2,2-dimethyl-3-butanol |
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| 37. |
If 25geach of CaCO3 and H2SO4 react wiith each other the amount of CaSO4 formed? |
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Answer» Answer: Explanation: CaCO3 + H2SO4 ------> CASO4 + CO2 + H2O 25g of CaCO3 = 0.25 moles of CaCO3 0.25 moles give 0.25 moles of CaSO4 Molar mass of CaSO4 is 136 0.25 moles weigh 34g |
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| 38. |
Which of the following has hihigest percentageof O2 by weight a.CH3OH b.H2O c.HCOOH |
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Answer» B. |
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| 39. |
A container 18.0g water then it does not containa.1NAwater molecule b.1NA h atomsc.1NA O atoms |
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Answer» HEY MATE,HERE'S YOUR ANSWER Explanation: a)1NAwater molecules KINDLY MARK ME THE BRAINLIEST... |
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| 40. |
During laboratory preparation of hydrogen chloride gas from NaCl and conc. H2SO4, temperature should be maintained and controlled. Why |
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Answer» Explanation: The reaction occurs at ROOM TEMPERATURE. Sulphuric ACID acts as a REACTANT as well as a drying agent.The reaction occurs at room temperature. Sulphuric acid acts as a reactant as well as a drying agent.NaCl+H2SO4→NaHSO4+HClhope it helps!!✌ |
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| 41. |
How do we apply (4n+2)π rule except for benzene to find out which is aromatic |
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Answer» Explanation:
hope it helps!!mark it as the brainliest!!✌ |
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| 42. |
Q)Write the KC expression and also find the unit of KC for the reaction . 4Hcl +O2 |
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Answer» Answer: Kc is the concentration of the reaction, it is usually shown as: c[C]c[D]c[A]c[B] Kp is the amount of partial PRESSURE in the reaction, usually shown as: p(C)p(D)p(A)p(B) As we have seen above, Kp = Kc (RT)Δn,we can DERIVE this formula from the IDEAL Gas LAW. |
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| 43. |
cylinder A contains 4.6 grams of C2H5OH and cylinder B has 3 grams of C2H6 a: both cylindar A and B have equal number of molecules b: cylindar A has greater molecules than B c: both cylindars have equal number of hydrogen atoms d: both a and b |
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Answer» atoms" (and any subsequent WORDS) was ignored because we limit QUERIES to 32 words. Explanation: |
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| 44. |
Which metal is used for galvanisation of iron? |
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Answer» Answer: zinc Explanation: GALVANISATION or GALVANIZATION (or galvanizing as it is most commonly called) is the process of applying a protective zinc coating to iron or steel, to prevent rusting. The most COMMON method is hot dip galvanizing, in which steel SECTIONS are submerged in a bath of molten zinc. |
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| 45. |
Yoo cmmothano Es burntEn Just sufreccentform Carbon drondegouand Stoam. If au themeasurcomento100°C-the compositesof resultingmonturo.Almal |
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| 46. |
How many elements are present in two molecules of aspirin the formula of aspirin is C9H8O4A. 42B. 21C. 6D. 3 |
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Answer» Answer: THREE elements There are only three elements in two molecules of aspirin. If the formula for aspirin is C9H8O4, then there are nine carbon atoms, eight hydrogen atoms, and four OXYGEN atoms on every molecule of aspirin. It will not CHANGE from molecule to molecule. |
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| 47. |
Sominutes of outgoingmetal3.25of the mass ofbar which109 is 15kSpind its mas permeter my answer is 4 8/13 |
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| 49. |
Why nitrogen is gas where as phosphours is solid out at room tempretaure? |
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Answer» Answer: DUE to larger atomic size it does not FORM pi BONDS with itself. Hence, in P4 molecule P forms sigma bond with other phosphorous atoms. ... So, since the force of attraction between Phosphorous molecules is high and that between Nitrogen molecules is low, Phosphorous is a SOLID while Nitrogen is a GAS. |
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| 50. |
Dinitrogen monoxide (more commonly called nitrous oxide) has the chemical formula N2O. What is the mass percent oxygen in nitrous oxide? |
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Answer» Answer: mass percent = molar mass of oxygen×100 ------------------------------- total MOLECULAR mass of COMPOUND =. 16 ×100÷44 =36.36% HOPE this HELPS you and PLZ mark this answer as brainliest answer. |
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