check for understanding:\n1) which formula re...

check for understanding:\n1) which formula represents an alkane?\na) c₂h₂ b) c₂h₄ c) c₃h₄ d) c₃h₈\n2) which type of bond occurs in a saturated hydrocarbon molecule?\na. single covalent c. triple covalent\nb. double covalent d. ionic\n3) given the formula representing a compound:\nh h h h\nh - c - c - c = c - c - h\nh h h h\nwhat is a chemical name of this compound?\na) 2 - pentene b) 2 - pentyne\nc) 3 - pentene d) 3 - pentyne

Answer

### 1) # Explanation: ## Step1: Recall the general formula of alkanes The general formula for alkanes is \(C_nH_{2n + 2}\). ## Step2: Check each option - For \(n = 2\) in \(C_nH_{2n+2}\), \(H\) atoms \(=2\times2 + 2=6\). So \(C_2H_2\) (\(n = 2\), \(H=2\)) and \(C_2H_4\) (\(n = 2\), \(H = 4\)) are not alkanes. - For \(n=3\) in \(C_nH_{2n + 2}\), \(H\) atoms \(=2\times3+ 2=8\). \(C_3H_4\) (\(n = 3\), \(H = 4\)) is not an alkane, while \(C_3H_8\) (\(n=3\), \(H = 8\)) follows \(C_nH_{2n+2}\). # Answer: D. \(C_3H_8\) ### 2) # Explanation: ## Step1: Define saturated hydrocarbons Saturated hydrocarbons have only single - covalent bonds. Alkanes are saturated hydrocarbons. ## Step2: Analyze bond types - Double covalent bonds (\(C = C\)) are in alkenes (unsaturated). - Triple covalent bonds (\(C\equiv C\)) are in alkynes (unsaturated). - Ionic bonds are between metal and non - metal (not in hydrocarbons which are made of \(C\) and \(H\), both non - metals). # Answer: A. single covalent ### 3) # Explanation: ## Step1: Count the number of carbon atoms The longest carbon - chain has 5 carbon atoms (\(n = 5\), root name 'pent'). ## Step2: Identify the functional group and its position There is a double bond (\(C = C\), alkene). Numbering the carbon - chain from the end closer to the double bond, the double bond is between \(C - 2\) and \(C - 3\). The name of the compound is based on the position of the double bond. # Answer: A. 2 - pentene