\[ \mathrm{CH_3COOH + NaOH \;\longrightarrow\; CH_3COONa + H_2O} \]
\[ \mathrm{2\,CH_3COOH + Na_2CO_3 \;\longrightarrow\; 2\,CH_3COONa + H_2O + CO_2 \uparrow} \] \[ \mathrm{CH_3COOH + NaHCO_3 \;\longrightarrow\; CH_3COONa + H_2O + CO_2 \uparrow} \]
Write notes on the following:
(a) Saturated and unsaturated hydrocarbons
(b) Corrosion
(c) Precipitation reaction
Find the unknown frequency if 24 is the median of the following frequency distribution:
\[\begin{array}{|c|c|c|c|c|c|} \hline \text{Class-interval} & 0-10 & 10-20 & 20-30 & 30-40 & 40-50 \\ \hline \text{Frequency} & 5 & 25 & 25 & \text{$p$} & 7 \\ \hline \end{array}\]
Two concentric circles are of radii $8\ \text{cm}$ and $5\ \text{cm}$. Find the length of the chord of the larger circle which touches (is tangent to) the smaller circle.