Among the following,the one that gives a positive iodoform test upon reaction with $I_2$ and $NaOH$ is

What is the decreasing order of reactivity of $HX$ in the reaction $ROH + HX \to RX + H_2O$?

What is the major product of the following reaction?

$A$ $\xrightarrow{K_2Cr_2O_7 / \text{dil. } H_2SO_4} B$ $\xrightarrow{CH_3MgI / H_2O} CH_3-C(CH_3)(OH)-CH_3$. The reactant $A$ is:

An organic compound $(A)$ (molecular formula $C_{6}H_{12}O_{2}$) was hydrolysed with dil. $H_{2}SO_{4}$ to give a carboxylic acid $(B)$ and an alcohol $(C).$ $C$ gives white turbidity immediately when treated with anhydrous $ZnCl_{2}$ and conc. $HCl$. The organic compound $(A)$ is

Which of the following combinations cannot be used to prepare the alcohol $Ph-C(OH)(CH_3)-CH_2-CH_3$?