General Chemistry PHARM-101: Stoichiometry Quiz

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the correct unit for expressing molarity?

grams of solute / 1000 g solution

milliliters of solute / 100 mL solution

grams of solute / 100 mL solution

moles of solute / liter of solution (correct)

Which of the following correctly describes how to calculate molarity from weight of solute and molecular weight?

M = weight (g) / molecular weight (g/mol) / volume (L)

M = weight (g) × molar mass (g/mol) / volume (L)

M = weight (g) / molecular weight (g/mol) × volume (L) (correct)

M = weight (g) / molar mass (g/mol) × volume (L)

How many grams of KBr are necessary to create a 0.500 M solution in 2.00 L of water?

119 g

119 g × 2.00

119 g × 0.500

119 g × 0.500 × 2.00 (correct)

If you have a solution with a concentration of 0.125 M NaOH, how many liters of this solution would contain 0.255 mol of NaOH?

0.63 L Signup and view all the answers

Which concentration unit represents the amount of solute present in 100 g of solution?

% Weight Signup and view all the answers

How many liters of solution are needed to contain 0.255 mol of NaOH at a concentration of 0.125 M?

1.02 L Signup and view all the answers

What characteristic defines a strong electrolyte?

They completely ionize when dissolved in water. Signup and view all the answers

Which of the following is true regarding salt and sugar when dissolved in water?

Salt is an electrolyte while sugar is a nonelectrolyte. Signup and view all the answers

What happens to the ions of sodium chloride when it dissolves in water?

They dissociate and are surrounded by water molecules. Signup and view all the answers

What is the resulting property of a solution of sugar in water?

It does not conduct electricity. Signup and view all the answers

In terms of solvation, what role do solvent molecules play when a solute dissolves?

They attract solute particles, separating and surrounding them. Signup and view all the answers

What is the relationship between molarity and volume when calculating the amount of solute needed?

Molarity is the number of moles of solute per liter of solution. Signup and view all the answers

Which of the following compounds is categorized as a strong electrolyte when dissolved in water?

Ammonium chloride Signup and view all the answers

Which of the following substances does not ionize when dissolved in water?

Sugar Signup and view all the answers

Which statement accurately describes weak electrolytes?

They only partially ionize in water. Signup and view all the answers

Which of the following is an example of a non-electrolyte?

Ethanol Signup and view all the answers

What is the primary property of strong acids in an aqueous solution?

They fully dissociate into ions. Signup and view all the answers

Which electrolyte is commonly used to treat hypokalemia?

Potassium chloride Signup and view all the answers

Which of the following best describes magnesium chloride in terms of electrolyte classification?

Strong electrolyte Signup and view all the answers

Which of the following compounds produces a weak electrolyte solution?

Ammonium hydroxide Signup and view all the answers

Which substance would you consider a strong base?

Sodium hydroxide Signup and view all the answers

What is the general form of a synthesis reaction?

A + B ⟶ AB Signup and view all the answers

Which of the following is an example of a decomposition reaction?

2 H2O ⟶ 2 H2 + O2 Signup and view all the answers

In a single replacement reaction, which of the following occurs?

A + BC ⟶ AC + B Signup and view all the answers

What type of reaction is represented by the equation 8Fe + S8 ⟶ 8FeS?

Synthesis Reaction Signup and view all the answers

Which statement correctly describes a double replacement reaction?

The anions and cations of two compounds switch places. Signup and view all the answers

Which of the following is a characteristic of a weak acid?

Only partially dissociates in solution. Signup and view all the answers

What is the result of the electrolysis of water?

Production of hydrogen gas and oxygen gas. Signup and view all the answers

Which reaction can be classified as a replacement reaction?

Mg + 2 H2O ⟶ Mg(OH)2 + H2↑ Signup and view all the answers

How can you identify a decomposition reaction from the following options?

It produces two or more products from one reactant. Signup and view all the answers

Study Notes

Course Information

Course title: General Chemistry for Pharmaceutical Sciences
Course code: PHARM-101
Instructor: Dr. Azza H. Rageh
Department: Pharmaceutical Analytical Chemistry
University: Taibah University

Stoichiometry

Stoichiometry: calculations of the quantities of reactants and products in a chemical reaction.
Stoichiometry enables predicting product amounts based on reactant amounts.
Stoichiometry determines the necessary reactants to produce a given amount of product.
Coefficients in a balanced chemical equation represent the relative amounts in moles of each substance involved.

Reaction Stoichiometry

Example: 2 C8H18(l) + 25 O2(g) → 16 CO2(g) + 18 H2O(g)
2 moles of C8H18 react with 25 moles of O2 to form 16 moles of CO2 and 18 moles of H2O.

Solution Concentration

Concentration: the amount of solute present in the solution.
Concentration units: percentage by weight (%, w/w), percentage by volume (%, v/v), percentage by weight per volume (%, w/v), parts per million (ppm), parts per billion (ppb), molarity (M), formality (F), normality (N), molality (m).
Molarity (M): moles of solute per liter of solution.

Solution Concentration Calculations

Molarity (M) = weight (g) / molecular weight x volume (L)

Types of Aqueous Solutions

Solution: homogeneous mixture of two or more substances.
Solvent: substance present in the largest amount.
Solute: all other substances.
Example: sugar dissolved in water; water is the solvent, sugar is the solute.
Concentrated solution: relatively high proportion of solute to solvent.
Dilute solution: relatively low proportion of solute to solvent.

Electrolytes and Nonelectrolytes

Electrolytes: substances that dissolve in water to form solutions that conduct electricity.
- Strong electrolytes: completely ionize in water (e.g., ionic salts, strong acids, and strong bases).
- Weak electrolytes: partially ionize in water (e.g., weak acids and weak bases).
Nonelectrolytes: substances that do not ionize in water (e.g., molecular substances like sugar and alcohol).

Chemical Reactions in Pharmacy

Example Electrolytes: Magnesium sulfate, Ammonium chloride, Sodium chloride, Sodium acetate, Magnesium chloride, Potassium chloride, Calcium chloride

Types of Chemical Reactions

Synthesis reaction: two or more reactants combine to yield one product (A + B → AB).
Decomposition reaction: a complex substance breaks down into simpler parts (AB → A + B).
Replacement reactions: single replacement (A + BC → AC + B) and double replacement (AB + CD → AD + CB).

Reactions Involving Oxidation-Reduction (Redox)

Oxidation-Reduction (redox) reactions involve electron transfer from one reactant to another.
Oxidation: loss of electrons.
Reduction: gain of electrons.
Example: 2 Na(s) + Cl2(g) → 2 NaCl(s). Also includes Rusting of iron, Combustion of octane, Combustion of hydrogen.
Oxidizing agent causes oxidation in a reaction.
Reducing agent causes reduction in a reaction.

Chemical Reactions Between Ions

Water formation: metal hydroxide + acid → salt + water (acid-base reaction).
Weak electrolyte formation: strong acid + salt containing a weak acid anion → weak acid.
Precipitate formation: occurs when dissolved ion concentration exceeds the solubility limit.
Gas formation: products are gaseous, or if unstable product decomposes.
Complex ion formation: Lewis acid (metal ion) + Lewis base (ligand) → complex ion.

Assessment Questions (Examples)

Questions regarding solution concentrations, types of chemical reactions, solution preparation, and identifying reactants and products of given reactions.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Test your understanding of stoichiometry in chemical reactions and solution concentrations from the General Chemistry for Pharmaceutical Sciences course. This quiz will cover calculations of reactants and products based on balanced equations and concentration units.