Hyperconjugation and steric inhibition of resonance

13 questions on Hyperconjugation and steric inhibition of resonance from the General Organic Chemistry I: Electronic Effects chapter: 2 NEET level, 5 JEE Main, 6 JEE Advanced. Each one opens with its answer and solution.

• Count the number of hydrogens on sp3 carbons directly attached to the positively charged carbon of the ion shown. NEET level, drawn structure
• How many hyperconjugative (no-bond resonance) structures can be drawn for the ion shown, not counting the structure drawn? NEET level, drawn structure
• Count the number of hydrogens on sp3 carbons directly attached to the positively charged carbon of the ion shown (the number of hyperconjugative structures). JEE Main level, drawn structure
• Count the number of hydrogens on sp3 carbons directly attached to the positively charged carbon of the ion shown. JEE Main level, drawn structure
• Count the number of hydrogens on sp3 carbons directly attached to the two sp2 carbons of the alkene shown (the number of hyperconjugative C-H bonds). JEE Main level, drawn structure
• Compared with 4-nitrophenol (pKa about 7.2), the compound shown is a weaker acid (pKa about 8.3). The reason is JEE Main level, drawn structure
• 2,6-Dimethyl substitution makes the acid shown stronger than benzoic acid. The best explanation is JEE Main level, drawn structure
• The alkene shown is protonated by acid at the carbon that gives the more stable carbocation. Count the number of hydrogens on sp3 carbons directly attached to t... JEE Advanced level, drawn structure
• The compound shown is compared with 4-nitrophenol and with phenol. Which order of acidity (decreasing from left to right) is correct? JEE Advanced level, drawn structure
• Select all correct statements about the compound shown. JEE Advanced level, drawn structure
• Hydrogens on sp3 carbons directly attached to a C=C carbon take part in hyperconjugation. A reference alkene is shown. Select all of the alkenes shown that have... JEE Advanced level, drawn structure
• The cation shown undergoes a 1,2-methyl shift to give a more stable cation. How many hydrogens are on sp3 carbons directly attached to the positively charged ca... JEE Advanced level, drawn structure
• The alcohol shown is heated with concentrated acid and gives the most substituted alkene as the major product, via the most stable carbocation. How many hydroge... JEE Advanced level, drawn structure