What should be the tolerable limit of fluoride ions in drinking water ? What happens if it is higher than 10 ppm.

What happens when XeF_6 is heated with water ?

What should be the maximum average velocity of water in a tube of diameter 2 cm so that the flow is laminar? Viscosity of water is 10^3 Ns m^(-2) .

What happens when magnesium nitride is boiled with water ?

A spherical conductor having a charge of 100 muC is brought near another metallic sphere (of mass 36 kg) resting on earth's surface. What minimum distance of separation should be maintained, so as to lift up the metallic sphere with uniform speed. What happens, if the separation is more or less than the calculated value. (Take g =10 ms ^(-2 ) ) .

A ball is dropped from a bridge at height of 176.4m over a river. After 2 seconds a ball is thrown straight downwards. What should be the initial velocity of the second ball so that both hit the water simultaneously.