Question

Table reading for A is a solution of trioxonitrate (iv) acid of unknown concentration B is a standard solution of sodium hydroxide NaoH containing 4.00, 25cm3 portion of solution A for complete neutralization
1 state with a reason a suitable indicator
2 write a balance equation for the reaction
3 calculate the concentration of solution B in mol/dm3
b. Calculate the concentration of solution A in mol/dm3
C. Calculate the concentration in gram/dm3 of HNO3 in solution A

Answer 1

You should have proof read your post. It is incomplete as is. 4.00 what in what? The last part beginning with 25 cc and ending with neutralization is not a complete sentence.
The correct answer for 1 is as follows: Look up indicators, find one that changes at a range of pH = 7.0 and use that one. In practice, phenolphthalein or methyl red are good. The tables will give you phenol red or bromothymol blue.