`2/5` of `25`

Prove that following : cos(2sin^-1(-2/5)) = 17/25

The pK_(b) of CN^(Theta) is 4.7 . The pH is solution prepared by mixing 2.5 mol of 2.5 mol of KCN of 2.5 mol of HCN in water and making the total volume upto 500mL is

The pK_(b) of CN^(Theta) is 4.7 . The pH is solution prepared by mixing 2.5 mol of 2.5 mol of KCN of 2.5 mol of HCN in water and making the total volume upto 500mL is

Find the value of 2.5^2 + 2 ( 2.5 ) ( 7.5 ) + 7.5^2

The value of (5.(25)^(n+1) + 25.(5)^(2n-1))/(25.(5)^(2n) -105(25)^(n-1)) is :

Mean of 10 observations is 50 and their standard deviation is 10. If each observation is subtracted by 5 and then divided by 4, then the new mean and standard deviation are a) 22.5, 2.5 b) 11.25, 2.5 c) 11.5, 2.5 d) 11,2.5

What volume of NH_(3) gas at STP would be needed to prepare 100 ml of 2.5 molal (2.5 m) ammonium hydroxide solution?

What volume of NH_(3) gas at STP would be needed to prepare 100 ml of 2.5 molal (2.5 m) ammonium hydroxide solution?