# chemistry

Acids and bases
• What is an acid?
• A 500cm3 solution containing 1.9g of a weak acid HA has a pH of 3.50. Calculate the molar mass of the acid, given that it has a Ka of 2.0 × 10-6moldm-3
• Calculate the pH of the following:
• 0.002moldm-3 NaOH
• 0.30 moldm-3 NH4Br
• 0.001moldm-3 H2SO4

1. 👍
2. 👎
3. 👁
1. You can get the definition of an acid from you text/notes/google.

For the HA problem. For pH = 3.50 convert to (H^+). I obtained approx 3E-4 but you need to confirm since that's an estimate.
.......HA ==> H^+ + A^-
E......x....3E-4...3E-4

Substitute the E line into the Ka expression and solve for (HA).
Then (HA) = M = mols/L. YOu have M and L, solve for mols.
Then mols = grams/molar mass. You have mols and grams, solve fo rmolar mass. Remember to use the real value for (H^+) and not my estimate.

1. 👍
2. 👎
2. By the way, the Ka value has no units and don't let anyone tell you they do. When they are used, most of the time they are called just units, but often they are called "tentative units". "temporary units", "trial units", or

1. 👍
2. 👎

## Similar Questions

1. ### Chemistry

Write the formulas of the conjugate acids of the following Brønsted-Lowry bases. A.C4H4N− B.(SO4)2− C.(CH3)3N Write the formulas of the conjugate bases of the following Brønsted-Lowry acids. A.HCN B.(CH3)2NH2+ C.H2SO4

2. ### chemistry

a patient receives 250 mL of a 4.0% (m/v) amino acid solution twice a day. a) how many grams of amino acids are in 250mL of solution? b) how many grams of amino acids does the patient receive in one day? For a) I came up w/10g and

3. ### Chemistry - Acid and Bases

In aqueous solution, classify these compounds as strong acids, weak acids, strong bases, weak bases, or other. HNO3 HBr HF CH3COOH H3PO4 NaOH Ba(OH)2 (CH3)3N NH3 NaCl

4. ### Chemistry

Both carboxylic acids and phenols react with strong bases to produce _____. gaseous products the conjugate base of the carboxylic acid or phenol a complex with water a stronger acid or phenol

1. ### Chemistry

I am stumped on this one...Please help!!! Write a balanced base ionization reaction for methylamine (CH3NH2) in water. Identify all species as acids and bases and identify the conjuate acid-base pairs.

2. ### Chm 2

The question asks, Consider the following weak acids and their Ka values Acetic acid Ka = 1.8x10^-5 Phosphoric acid Ka = 7.5x10^-3 Hypochlorous acid Ka = 3.5x10^-8 What weak acid-conjugate base buffer system from the acids listed

3. ### ChEmIsTrY--THANK YOU!

Is these true or false: -Every Bronsted-Lowry acid is also a Lewis acid. -Conjugate acids of weak bases produce more acidic solutions than conjugate acids of strong bases. Thank you very much!

4. ### --- Chemistry ---

What is the most common chemical method for removing H_30^+ ions in aqueous solution? Write a net ionic equation which describes this method. Add a base. What happens to the H concentration when the OH concentration goes up? We

1. ### Chemistry (PLZ HELP)

1. Outline a procedure to prepare an ammonia/ammonium buffer solution. I'm confused how to start it off. This is an outline of how the steps should be: Step One - Calculate the concentration of hydronium ions in the solution that

2. ### Chemistry 12

9. According to Arrhenius, which of the following groups contain: i)only acids ii)only bases a. NaOH, H2CO3, KCl b. MgCl2, H2SO4, HCl c. HNO3, HCl, H3PO4 d. Mg(OH)2, AgBr, HF e. KOH, NH4OH, Ba(OH)2 10. Enough water is added to 100

3. ### chemistry

Hydrocyanic acid (HCN) is a much weaker acid than nitrous acid (HNO2). The pH values of 0.1 M solutions of the potassium salts of these two acids were determined separately. The statement which describes these determinations most

4. ### Chemistry

For the following acids: i. CH3COOH ii. HNO2 iii. HCN a) What is the dissociation equation in an aqueous solution? b)Give the KA expression for each of the acids. c)Identify the acid-base pairs.