Acetaldehyde forms a white crystalline precipitate on mixing with a ...... solution of

Solution $X$ contains $Na_2CO_3$ and $NaHCO_3$. $20 \ mL$ of $X$ when titrated using methyl orange indicator consumed $60 \ mL$ of $0.1 \ M$ $HCl$ solution. In another experiment,$20 \ mL$ of $X$ solution when titrated using phenolphthalein consumed $20 \ mL$ of $0.1 \ M$ $HCl$ solution. The concentrations (in $mol \ L^{-1}$) of $Na_2CO_3$ and $NaHCO_3$ in $X$ are respectively:

Find the equation of the parabola whose axis is parallel to the $y$-axis and which passes through the points $(0, 4), (1, 9),$ and $(4, 5)$.

$A$ Carnot engine having an efficiency of $1/10$ as a heat engine is used as a refrigerator. If the work done on the system is $10 \, J$,the amount of energy absorbed from the reservoir at a lower temperature is .......... $J$.

$A$ man is admitted to a hospital. He is suffering from an abnormally low body temperature,loss of appetite,and extreme thirst. His brain scan would probably show a tumour in

Which of the following is the strongest $o-p$ directing group?