Question
White phosphorus is stored in which of the following
substances?Solution
White phosphorus is a translucent white solid , is poisonous and insoluble in water. It glows in the dark (Chemiluminiscence). It is less stable and hence , more reactive. It is soluble in Carbon disulphide. Its molecular formula is P4. It is kept under water because it is highly reactive, and spontaneously combusts when exposed to the air. Hence, option B is correct.
If 0 ≤ θ ≤ 90°, and sin(2 θ +50°) = cos (4 θ + 16°), then what is the value of θ (in degrees)?
sin10˚ x sin20˚ x sin40˚ =?
If (2sin A + cos A) = 3sin A, then find the value of cot A.
If tan 4θ = cot 14θ, then find the value of cos 9θ.
If sin A = 3/5 and cos B = 4/5, where A and B are acute angles, find the value of sin(A + B).
If √3cosec 2x = 2, then the value of x:
If tan θ + cot θ = 2 where 0 < θ < 90 ; find the value of tan30 θ + cot 29 θ.
- If sin (3A − 4B) = (1/2) and cos (A + B) = (√2/2), where 0° < A, B < 90°, then find the value of ‘A’.
If θ is an acute angle and sin θ + cosec θ = 2, then the value of sin2 θ + cosec2 θ is:
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