balance this equation URGENT?

Question

WRite a full chemical equation for tje reaction that would mark the end point for the reaction of the phosphoric acid with an aqueous soltion of sodium hydroxide using methyl violet indicator??

When a compund binds more strongly to the stationary phase that does what to the rf value??

A sample of Brass contains 64% copper by mass. zinc will react with the dilute acid but not copper. what volume of hydrogen gas would be expected to be formed at SLC when a 3.567g powered sample of brass is allowed to react with excess dilute hydrochloric acid??
(I have four alternatives for this answer so i can establish if ur well off or not))

Thanks heaps everyone... My tutor is struggling which is a worry, I know. If you can please show valid explanations to solutions

Answer 1

H3PO4 (aq) + 3 NaOH (aq) --> Na3PO4 (aq) + 3 H2O (l)

[C24H28N3H2]+3 (yellow) + 2 OH- --> [C24H28N3]+ (violet) + 2 H2O

If a compound binds more strongly to the stationary phase then it will move in the mobile phase more slowly causing the Rf value to decrease.

Zn (s) + 2 HCl (aq) --> ZnCl2 (aq) + H2 (g)

One mole of Zn will produce one mole of H2 gas.

3.567 g / 65.41 g/mol = 0.0545 mole of Zn

Now solve PV = nRT for volume:

V = (nRT)/P where n = 0.0545 mole and T and P are the standard conditions. R is the gas constant.

Answer 2

count kind out each atom on the two element undergo in recommendations that Pb has an ox. state of (+4) and Ba has (+2). the expenditures on the two factors as properly because of the fact the atoms might desire to stability. (SO4) is -2 and (OH) is -a million