Which of the following species is not electrophilic in nature?

Which of the following is a self-adjusting force?

If the direction cosines of two lines are given by $l+m+n=0$ and $l^2-5m^2+n^2=0$,then the angle between them is

If $a^x = b$,$b^y = c$,and $c^z = a$,then the value of $xyz$ is:

$4 \ g$ of a hydrocarbon on complete combustion gave $12.571 \ g$ of $CO_2$ and $5.143 \ g$ of water. What is the empirical formula of the hydrocarbon?

$A$ thermally insulated vessel contains an ideal gas of molecular mass $M$ and ratio of specific heats $\gamma$. It is moving with speed $v$ and is suddenly brought to rest. Assuming no heat is lost to the surroundings,its temperature increases by