If $A+C=2B$,then $\frac{\cos C-\cos A}{\sin A-\sin C}$ is equal to

If the straight lines $2x + 3y - 1 = 0$,$x + 2y - 1 = 0$ and $ax + by - 1 = 0$ form a triangle with the orthocentre at the origin,then $(a, b) =$

One litre of oxygen at a pressure of $1 ~atm$ and two litres of nitrogen at a pressure of $0.5 ~atm$ are introduced into a vessel of volume $1 ~L$. If there is no change in temperature,the final pressure of the mixture of gas (in $atm$) is

Freundlich adsorption isotherms for the physical adsorption of a gas at temperatures $T_1$,$T_2$,and $T_3$ are shown in the graph given below. The correct relationship between $T_1$,$T_2$,and $T_3$ is:

Two gaseous equilibria $SO_{2(g)} + \frac{1}{2} O_{2(g)} \rightleftharpoons SO_{3(g)}$ and $2 SO_{3(g)} \rightleftharpoons 2 SO_{2(g)} + O_{2(g)}$ have equilibrium constants $K_{1}$ and $K_{2}$ respectively at $298 \ K$. Which of the following relationships between $K_{1}$ and $K_{2}$ is correct?

What are the harmful effects of photochemical smog and how can they be controlled?