The active ingredient in aspirin is acetylsalicylic acid (hc9h7o4), a monoprotic acid with a ka of 3.3×10−4 at 25 ∘c . you may want to reference (pages 680 - 690) section 16.6 while completing this problem. what is the ph of a solution obtained by dissolving two extra-strength aspirin tablets, containing 440 mg of acetylsalicylic acid each, in 270 ml of water? express your answer to two decimal places.

pH = 2.76

Explanation:

Given that:

Given that:

Mass = 440 mg = 0.44 g (1 mg = 0.001 g)

Molar mass = 180.158 g/mol

The formula for the calculation of moles is shown below:

Thus,

Given Volume = 270 mL = 0.27 L ( 1 mL = 0.001 L)

Concentration = 0.00904 M

Consider the ICE take for the dissociation of acetic acid as:

                                   HC₉H₇O₄    ⇄     H⁺ +     C₉H₇O₄⁻

At t=0                          0.00904                 -              -

At t =equilibrium      (0.00904-x)                x           x            

The expression for dissociation constant of acetic acid is:

x is very small, so (0.00904 - x) ≅ 0.00904

Solving for x, we get:

x = 1.7272×10⁻³  M

pH = -log[H⁺] = -log(1.7272×10⁻³) = 2.76

out of these options:

ability to burn paper

pure sodium reacting violently with water

the boiling point of water

helium does not tend to react with anything

i would say this is a physical property:

helium does not tend to react with anything

why? :

i said helium does not tend to react with anything because well, it reacts to ! but ability to burn paper, pure sodium reacting violently with water, & the boiling point of water are chemical or

physical properties: the properties of a substance that can be observed without changing the chemical makeup of the substance

chemical properties: properties of a substance relating to the chemical nature and reactivity of the substance

- calcium has greater affinity to bond with electron receptors than hydrogen does and hence, it has the ability to replace hydrogen in most of its compounds.

- lithium has 2 valence electrons in the product because it can make only 1 bond with hydrogen. beryllium has 4 valence electrons in the product because it can only make 2 bonds. it has fewer electrons than neon and can react with electron donors. each hydrogen has 2 valence electrons, the same as helium.

- the covalent bond formed between carbon and hydrogen is polar because carbon is more electronegative than hydrogen and it attracts the bonded electron pair closer to itself, thus giving hydrogen a partial positive charge.

- a hydrogen bond is a relatively weak bond that hydrogen atoms make with the electronegative atoms nitrogen, oxygen or fluorine.

so the best choice is a.) 2 calcium (ca) atoms