Acid-Base

What is the acid dissociation constant of a weak acid if a concentration of 0.3M gives a hydrogen-ion concentration of 0.001M?

I really need alot of help with this

C + S8 ----= CS2              what type is this?

synthesis, decomposition, single displacement, or double didplacement, or combustion?

please help.

How do i find the ph from using the formulas for acids and bases?

What formulas do I use?

A student titrated a spoonful of an unknown monoprotic acid with an NaOH solution of unknown concentration. After adding 5.00 ml of base, he found the pH of the solution to be 6.0. The equivalence point came when he added 7.00 ml of additional base. Calculate the dissociation constant of the acid.

How do I go about this problem??? Please show me the steps!
Thank you in advance!

So w/ a gas collection set up using an inverted graduated cylinder, an acid is dropped from a burrete into a base, it produces about 100 mL of gas. While an identical set up with a base being dropped into an acid prodcues 500 mL of gas

(SAME ACID AND BASE IN BOTH SET UPS)

WHY IS THIS HAPPENING???

We conducted a lab in class and my teacher gave me a lab report that is due tomorrow. We mixed phenolphthalein into hydrochloric acid and sodium hydroxide. (Turned different colours, except Hcl+pheno.) Then we mixed methyl orange into more hcl and naoh. We had to write our observations. Next she put sodium and potassium into water. (Exploded?) When she spilled hcl(I believe) she put vinegar on it for some reason. To write a purpose, I am trying to figure out the relationship between these things. Please help me.

We conducted a lab in class and my teacher gave me a lab report that is due tomorrow. We mixed phenolphthalein into hydrochloric acid and sodium hydroxide. (Turned different colours, except Hcl+pheno.) Then we mixed methyl orange into more hcl and naoh. We had to write our observations. Next she put sodium and potassium into water. (Exploded?) When she spilled hcl(I believe) she put vinegar on it for some reason. To write a purpose, I am trying to figure out the relationship between these things. Please help me.

Which species is a Lewis acid in the reaction:

FeCl₃ + Cl^-  --> FeCl₄^-

(a) FeCl₃   (b) Cl^-   (c) none

I feel that the answer is (c) because even though Cl^- only has 6 valence electron and has room to accept a pair of electrons (acting as an acid), but FeCl₄^- still has a negative charge. Not really sure...

What could you add to a Na₃PO₄ solution to form a buffer?

(a) NaCl   (b) K₃PO₄    (c) NaOH     (d) HCl

Na₃ PO₄  + 3H₂O  --> <-- 3NaOH + H₃PO₄

Na₃PO₄ is the conjugate base of the weak acid H₃PO₄

I know that Na₃PO₄ will dissociate into ions in solution, leaving the PO₄^3- ion.

If I could add anything to the solution, I would add H₃PO₄ to the solution to make the buffer, but it is not one of the options.

How many ml of .058 M H2CO3 are needed to neutralize 54 mlof .19 M bismuth hydroxide?

Step by step please