Calculate the hydrogen ion concentration in the following biological fluids whose `pH` are given below :
`(a)` Human muscle-fluid, `6.83` `(b)` Human stomach fluid, `1.2`
`(C)` Human blood `7.38` `(d)` Human saliva `6.4`

Calculate the pH of the following solution : (a) 2g of TlOH dissolved in water to give 2 litre of solution. (b) 0.3g of Ca(OH)_(2) dissolved in water to give 500mL of solution. (c) 0.3g of NaOH dissolved in water to give 200mL of solution. (d) 1mL of 13.6M HCl is diluted with water to give 1 litre of solution.

10 mLof H,A (weak diprotic acid) solutions is titrated against 0.1M NaOH. pH of the solution is plotted against volume of strong base added and following observation is made. If pH of the solution at 1^(st) equivalence point is pH_(1) and at 2^(nd) equivalnee point is pH_(2) , Cal the value (pH_(2),-pH_(1)) at 25^(@) C. Given for H_(2),A, p^(Kal) =4.6 &p^(Ka2) =8

The projection of the join of the points (3, 4, 2), (5, 1, 8) on the line whose d.c.'s are (2/7, -3/7, 6/7) is

If bar(a), bar(b), bar(c) are non coplanar vectors, then test for the collinearity of the following points whose position vectors are given. i) bar(a)-2bar(b)+3bar(c), 2bar(a)+3bar(b)-4bar(c), -7bar(b)+10bar(c) ii) 3bar(a)-4bar(b)+3bar(c), -4bar(a)+5bar(b)-6bar(c), 4bar(a)-7bar(b)+6bar(c) iii) 2bar(a)+5bar(b)-4bar(c), bar(a)+4bar(b)-3bar(c), 4bar(a)+7bar(b)-6bar(c)

Ascending order of number of solutions in the given interval of the following equations. (A) sin x = -1 in (0, 4pi) (B) cos x =-1//2 in (0, 4pi) (C ) tan x =-1 in (0, 6pi) (D) tan x = 1 in (0, pi//2)