Which of the following lubricates ligaments or tendons and is an important constituent of synovial fluid of bones?

Compound $PdCl_4 \cdot 6H_2O$ is a hydrated complex; $1 \, m$ aqueous solution of it has a freezing point of $269.28 \, K$. Assuming $100 \%$ ionization of the complex,calculate the molecular formula of the complex ($K_f$ for water $= 1.86 \, K \, kg \, mol^{-1}$,freezing point of pure water $= 273.15 \, K$).

Which of the following is a latex-based alkaloid?

If $f_n(x) = \log \log \log \ldots \log x$ (where $\log$ is repeated $n$ times),then $\int (x f_1(x) f_2(x) \ldots f_n(x))^{-1} dx$ is equal to

If ${}^n P_r = 30240$ and ${}^n C_r = 252$,then the ordered pair $(n, r)$ is equal to

Hydathodes are also called