2. Write the equilibrium expression for HF + H2O → F- + H3O+

(i) Find [H+] of a 0.056 M hydrofluoric acid solution. Ka = 1.45 x 10-7

(ii) Then calculate the pH

3. Write the equilibrium expression for NH3 + H2O → NH4+ + OH-

4. Write the equilibrium expression for H2S + H2O → H3O+ + HS- and

(i) Calculate the [H3O+] in a 0.45 M solution of hydrogen sulphide (H2S). Ka = 2.05 x 10-6,

(ii)Then calculate the pH of H2S?

5. Write the equilibrium expression for NH3 + H2O g NH4+ + OH-

(i) Calculate the [OH-] in a 0.60 M solution of ammonia (NH3) Kb = 6.83 X 10-4,

(ii)Then calculate the pHof NH3 (Base)

6. The pH in a 0.25 M solution of the acid HBrO is 4.65 . Using this, Write the equilibrium expression of
HBrO and calculate the value of Ka for the acid HBrO

Follow the steps provided in the simulation to add water to the graduated cylinder, select one of the three samples (copper, silver, or gold), set its mass to the values given in the statements below, and calculate its density. here is a summary of the steps required: add water by clicking and holding prepare a known volume of water button. until the desired volume of water has been added. if more than the desired volume is added, click the reset button. button and redo the procedure. a single click will add about 21.0 ml of water. to set the mass, click and hold weigh out metal button. until the desired amount of metal is added to the weighing pan. once the desired mass of the metal is added, release the button. transfer the metal to water and then click on calculate density button. to see how the density is calculated using water displacement to measure the volume of the solid. to save time you can approximate the initial volume of water to â±1 ml and the initial mass of the solid to â±1 g. for example, if you are asked to add 23 ml of water, add between 22 ml and 24 ml. which metals in each of the following sets will have equal density? check all that apply.

Which of the following is not a good technique for managing used oil? a) have specific, labeled catch pans available for technicians who are collecting oil b) spills in your shop and any releases on pavement or outside should be poured down a drain c) do not use oil containers for antifreeze or other non-similar fluids d) be prepared for oil spills with the proper absorbents

Use the drop-down menus to answer each question. which runner finished the 100 m race in the least amount of time? which runner stopped running for a few seconds during the race? at what distance did anastasia overtake chloe in the race?