CBMS107 Lecture Notes - Lecture 10: Stoichiometry, Weak Base, Equivalence Point

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marooncaribou266

3 Aug 2018

School

Macquarie University

Department

Chemistry Biomolecular Sciences

Course

CBMS107

Professor

Damian

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Document Summary

28th march 2018: lecture 14 acid and base stoichiometry: acids and bases: Acids dissociate to produce ions (h+) and bases dissociate to produce hydroxide ions (oh-: bronsted-lowry model: An acid is a substance that donates h+ to another substance and a base is a substance that accepts h: lewis model: The distinction between strong and weak acids or bases reflects the amounts of produced [h30+] and [oh-] respectively. [h30+] and [oh-] concentrations are small numbers. Water can react with itself leading to a process called autoionisation: stoichiometry: A reaction where both the acid and base are completely consumed leaving neither side of the equation acidic or basic = neutralization reaction. When a strong acid and base react, the product is salt + water. The base provides the cation, the acid provides the anion. A procedure for determining the amount of substance a adding a measured volume of a solution b with know concentration until the reaction between a and.

Related Questions

QUESTION 1

Which of the following substances is most acidic?

		Cowâs milk - pH 6.6
		Apple juice - pH 3.0
		Tomato juice - pH 4.5
		Distilled water - pH 7.0

2 points

QUESTION 2

A buffer is a substance that converts:

Alkaline solutions to neutral solutions.

Acidic solutions to alkaline solutions.

Strong bases or acids to weak bases or acids.

Acidic solutions to neutral solutions.

QUESTION 3

How does a solution of pH 7 compare to a solution of pH 10?

		pH 7 has more OH^- ions
		pH 7 is more basic
		pH 7 has a higher pH
		pH 7 has more H⁺ ions

2 points

QUESTION 4

According to the Arrhenius Theory of acids and bases, a base is:

A substance that decrease the amount of hydroxide ions present.

A substance that increases the amount of hydroxide ions present when it is dissolved in water.

A substance that increase the amount of hydrogen ions present.

A substance that increases the amount of hydrogen ions present when it is dissolved in water.

QUESTION 5

Which of the following are true regarding acid-base titrations?

		They are used to determine the concentration of an unknown acid or base.
		The acid or the base must be a standard solution with a known concentration
		The standard solution is titrated into the chemical with the unknown concentration.
		All of the above are true regarding acid-base titrations.

2 points

QUESTION 6

Which of the following is not an example of a neutralization reaction?

HCl + NaOH NaCl +H₂O

2 NaOH + H₂CO₃ Na₂CO₃ +2 H₂O

H₂SO₄ + 2 NH₄OH (NH₄)₂SO₄ + 2 H₂O

2 AgNO₃ + Zn 2Ag +Zn(NO₃)₂

QUESTION 7

Which acid base theory defines an acid as a proton donor and a base as a proton acceptor?

		Arrhenius Theory
		Bronsted-Lowery Theory
		Conjugate Pairs Theory
		Lewis Theory

2 points

QUESTION 8

The Arrhenius Theory states that acid-base reactions create a solution composed of a water and a salt. This is because mixing an acidic and basic solution together yields:

A neutral solution

A solution with a pH at or near 7

Both A and B are correct

QUESTION 9

Which of the following correctly defines a standard solution?

		A solution which always has the same molecular geometry.
		A solution in which the concentration is precisely known.
		A solution in which the volume is precisely known.
		A solution which always has different levels of solutes and solvents.

2 points

QUESTION 10

Acids naturally present in food are generally safe to eat because they are usually:

		Concentrated
		Dilute
		Weak
		Strong

None of the above are correct

.ill AT&T 9:44 AM Back Chem1B-W18-Homework5.pdf [1] This homework assignmenté·due at the begining of class on March 9., 2018, write your answers on a separate piece of paper, and show your work to receive credt Protiem 1 What distinguishes a strong acid from a weak acid7 What distinguishes a strong base from a weak base? Write out examples of the proton-transfer reaction for each as well as the equilibrium expression (K or Ko) tor each ? Wrtie equations Probiem 2 In class we dscussed e autoionization of water, What is an for the autoionization reactions for H-O and H SO Assume that both are pure iquids Problem 3 In class on Friday, we calculated the [HO-1 and [OH in stomach acid at pH 1.5 The average volume of an adult human stomach is 1L. How many H0 ions are present in a human stomach i&the pH is 2.0? How many OH- ions? man body temperatre). Problem4 any equlbnum constant. Min changes with temperature. At 37 â the pH of waner is 6.80. Caloulate the following for pure water at this temperature: b) IOH1 Problems whais a con ate acid-base pair? What is the relationship between the two members of pair? Prettem.6 Draw a Lewis structure ot each of thy tolowing acids. Then, wte balanced aciddssociaton reactions and equibrium expressions for each in water. a) Formic acid, HCOOH b) Chloric acid, HCIO, c) Dihydrogen arsenate, H As0 Probiem Z Dihydrogen arsenate is an ampiprotie substance, meaning tcan both accept and donane a proton Draw Lewis structures of the conjugate acid and the conjugate base of dihydrogen arsenate. Write the balanced base-dissociation reaction and equiibrium expression of dihydrogen arsenate in water Paatina successivo K.'s for polyprotic acids decrease. For thÃ© polyproc phosphoric acid. HAo, K., 7.2 x10. KA6.3 x 10, Ka 4.2 x 10- Draw Lewis structures of each of the species involwed in each acid- dissociation roactonãWhy d0the K.'s decrease for each successi e deprotaraton? Protiem 2 Hypochionous acid, HCIO, has a pka ol 7.54. What are the [Hs0-]. pH. [CO1 and [HCIO] in a 0.115 M solution of HCI0? Problema in a 0 735 M solution a weak acid is 12 5% dssoc ated. a) Calculatemo-1, pHÂ·[OH 1, and pH of the solution. b) Calculate Ka of the acid Problemi! Acetyisaleyic acid (asprin, structure shown to the right). HCæ¤:O4, is the most widely used pain reliever and tever reducer. Find the pH of 0.018 M aqueous aspirin at body temperature (K.: 3.6 x 104 at 37Â°C). Problem12 whyé·aqueous NaF basic but aqueous NaCl neutral? Chit consider the reaction of each anion with water 1 of 1 Previous Dashboard Calendar To Do Notifications Inbox

CBMS107 Lecture Notes - Lecture 10: Stoichiometry, Weak Base, Equivalence Point

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