Write the Name and Formula of the Fourth Member of the Following Homologous Series: A. Alkyne B. [22 / 36 / 29] 2. Write the name and molecular formula of the fourth member of alkane series. where n is the number of carbon atoms and OH represents the hydroxyl group.. Alcohols in the homologous series can be regarded as alkanes in which one hydrogen atom is replaced by a hydroxyl group. Alkanes that have 5 or more carbons are named using prefixes that indicate the number of carbons. Dear student! A homologous series is a group or family of organic compounds that has certain characteristics: (a) Members of the series can be represented by a general formula. class-10. Hence the molecular formula is. Write the name and molecular formula of the first member of the homologous series of alkynes. Give the name of each series. If you are on a personal connection, like at home, you can run an anti-virus scan on your device to make sure it is not infected with malware. [CBSE 2015] Answer: C n H 2n: Alkene 2 nd member = C 3 H 6 (propene) Question 14. $\begingroup$ @KaberiGhosh They're just two different approaches to defining the same concept. The alkanes comprise a series of compounds that are composed of carbon and hydrogen atoms with single covalent bonds. The alkane homologous series contains compounds that: Since one carbon will make a total of 4 covalent bonds, the first member (homologue) of the alkane homologous series must be 1 carbon atom bonded to 4 hydrogen atoms as shown below: The next homologue in the alkane homologous series will contain 2 carbon atoms with a single covalent bond between them, each carbon atom will make up its quota of 4 covalent bonds by bonding to 3 hydrogen atoms as shown below: and this molecule has the molecular formula C2H6. Therefore CH2 has a molar mass of 12 + (2 × 1) = 12 + 2 = 14 g mol-1. The carbons atoms are numbered so that the first of the two that are doubly bonded is given the lower of the two possible numbers. Since each CH2 unit has a molar mass of 14 g mol-1, the difference in molar mass between adjacent homologues is 14 g mol-1. C3H4 and C4H6 . C ethyne H C H Propyne, C 3 H 4, and butyne, C 4 H 6, are the next two members of the series. Write the formula of first two members of homologous series whose functional group is —CHO. The compounds are named as for the alkanes, but with the ending, “ ene ” instead of “ ane ”. Thus the molecular mass of each member differs by 14 atomic mass units. CH3-CH ( Propyene) n is 3. The first member is ethyne, C 2 H 2. Cloudflare Ray ID: 62cfa30e8c793128 Performance & security by Cloudflare, Please complete the security check to access. They differ from each other by a –CH 2 unit. The compound CH 3 CH=CHCH 2 CH 3, for example, has the double bond between the second and third carbon atoms. Answer (d) C 3 H 4. Alkene formula is written as C n H 2n. The vapour density of the fifth member of the homologous series of alkanes. Two consecutive number of 2nd and 3rd member of homologous series . The first member of alkyne series is ethyne with two carbon atoms bonded by a triple bond; H C ≡ C H. Answered By . 2] First member of alkane series. Occurrence In nature, methane is formed by the microbial activity of organic matter. (iv) Various homologous can be prepared by the general method of preparation for the series. Write the Name and Formula of the Fourth Member of the Following Homologous Series: A. Alkyne B. The first member of alkyne series is ethyne with two carbon atoms bonded by a triple bond; H C ≡ C H. Answered By . First write the parent chain of five carbon atoms: C–C–C–C–C. H has a molar mass of 1 g mol-1 • Q. Question 31. Alkyne homologous series contains compounds that: The first member, the first homologue, of the alkyne homologous series must contain 2 carbon atoms which are joined by a triple bond, and, because each carbon atom must make 4 bonds in total, each of the carbon atoms must be bonded to 1 hydrogen atom as shown below: The next member in the series, the next homologue, must contain 3 carbon atoms, and each C atom must make 4 bonds in total: Which is followed by the next homologue with 4 carbon atoms: So once again we can see that we are adding a CH2 unit to one homologue to make the next one in the series. Name the first member of alkyne family. Question 30. 0votes. Occurrence In nature, methane is formed by the microbial activity of organic matter. The first member of alkyne homologous series is ethyne as you need 2 carbons minimum to have a carbon connected with double bond. C 2 H 6, C 2 H 6 O, C 2 H 6 O 2, CH 4 O Answer: CH 4 O and C 2 H 6 O belong to the same homologous series. Answer: (a) Solution: A homologous series is a group of organic compounds having similar structures and similar chemical properties in which the successive compounds differ by group.. 4) They show a regular gradation in their physical properties (see the table-1). Examples. Question 31. asked Aug 16, 2019 in Class X Science by aditya23 ( … Each compound in the homologous series (a member) is referred to as a homologue (sometimes spelt homolog). The simplest family of compounds are called alkanes. We first write the carbon atoms joined together in a chain and then fill the ... (ii) alkyne with four carbon atom. HOMOLOGOUS SERIES OF C n H 2n-2 IS CALLED ALKYNE.. brainly.in/question/16721209 For the first member of the series (the first homologue), n=2, so the molecular formula for this compound will be C2H2×2 which is C2H4, For the second member of the series (the second homologue), n=3, so the molecular formula for this compound will be C3H2×3 which is C3H6. (ii) differ by a constant unit as you proceed from one member to another. 4. Subscribe to RSS headline updates from: Powered by FeedBurner. The series of organic compounds having same general formula and similar chemical properties but different physical properties in which one member differs from other member by single – CH 2 unit is known as homologous series. Rule 3. Answers and explanation of each question is … comprised of a series of compounds that contain carbon and hydrogen atoms with single covalent bonds Write the first four members of the homologous series that begins with H-C≡C-H. Also write down their general molecular formula. Here are the names and structures of five alkanes: Notice that the molecular models on the right show that the bonds are not really at angles of 90°. If you are at an office or shared network, you can ask the network administrator to run a scan across the network looking for misconfigured or infected devices. C 3 H 8 , C 4 H 1 0 , C 5 H 1 0 , C 7 H 1 2 a n d C 8 H 1 6 (b) Successive members differ from each other by –CH 2. The general formula for the homologous series of alkenes is CnH2n where n is the number of carbon atoms. Hence the molecular formula is. HOMOLOGOUS SERIES OF C n H 2n-2 IS CALLED ALKYNE.. Which means the difference in the molar mass between adjacent homologues in the series is 14 g mol-1: C has a molar mass of 12 g mol-1 The firSt member of the alkyne homologous series is (a) propyne (b) ethyne (c) methane (d) ethene (b) ethyne. The series of organic compounds having same general formula and similar chemical properties but different physical properties in which one member differs from other member by single – CH 2 unit is known as homologous series. Completing the CAPTCHA proves you are a human and gives you temporary access to the web property. CH3CH2C- CH (2-Brutyne) n is 4 . A homologous series is a family of organic compounds which follows a regular structural pattern, in which each successive member differs in its molecular formula by a –CH 2 – group.. Other homologous series include the alkenes, C n H 2n, the alkanols, C n H 2n+1 OH, and the carboxylic acids, C n H 2n+1 COOH. Nature's chemistry Hydrocarbons and homologous series. ... Write the molecular formula of first two members of homologous series having functional group –Cl. CnH2n-2. The homologues in a homologous series undergo similar chemical reactions because they have the same functional group. The first four alkanes in the homologous series retain their original names. then add CH2 to make C2H6 (the next homologue in the series), then add CH2 to make C3H8 (the next homologue in the series), then add CH2 to make C4H10 (the next homologue in the series), then add CH2 to make C5H12 (the next homologue in the series). The simplest alkane, methane, has one carbon atom and a molecular formula of CH 4. The general formula of alkyne is where n is the number of carbon atoms. Each blog post includes links to relevant AUS-e-TUTE tutorials and problems to solve. from neighbouring compounds. While writing out the name of the molecule, arrange the substituents in alphabetical order. Name the following : 1) second member of alkene series.