If $BaCl_2$ ionizes to an extent of $80 \ \%$ in aqueous solution,the value of van't Hoff factor is

$AB_{3(g)}$ dissociates as: $AB_{3(g)} \rightleftharpoons AB_{2(g)} + \frac{1}{2}B_{2(g)}$. When the initial pressure of $AB_3$ is $800 \ torr$ and the total pressure developed at equilibrium is $900 \ torr$,what percentage of $AB_{3(g)}$ is dissociated?

If $a, b, c$ are three non-coplanar vectors,then the vector equation $r = (1 - p - q)a + pb + qc$ represents a

Portland cement is manufactured using which of the following?

$A$ pair of perpendicular lines passes through the origin and also through the points of intersection of the curve $x^2+y^2=4$ with $x+y=a$,where $a>0$. Then $a$ is equal to

If the two circles $2x^2 + 2y^2 - 3x + 6y + k = 0$ and $x^2 + y^2 - 4x + 10y + 16 = 0$ cut orthogonally,then the value of $k$ is