Chemistry

Citations

Question 1: Reaction Identification + Prediction

Lesson progress
Explain the core ideas in Citations.Connect this section to Ideal Gas Model.Use the source-supported terminology and relationships accurately.

This lesson develops Citations as part of Ideal Gas Model. It uses the source curriculum to organize the important facts, relationships, examples, and vocabulary into a focused Stemosphere teaching sequence.

Key idea

Keep the central model in view: Citations explains observable patterns by connecting structure, process, evidence, and quantitative relationships.

For each reaction:

In Stemosphere terms, i. Classify the reaction type.ii. Predict whether it occurs.

a) Mg+Cu SO4 →
c) CH4 +O2 →
d) Ag NO3 +Na Cl→

In Stemosphere terms, determine oxidation states and identify oxidation/reduction.

2Fe2 O3 +3C→4Fe+3CO2

In Stemosphere terms, a) Oxidation state of Fe before and after

In Stemosphere terms, b) Oxidation state of C before and after

Determine oxidation number s:

Compound contains:

Actual molar mass = 148 g/mol
2Al+Fe2 O3 →Al2 O3 +2Fe

Actual Fe obtained:

In Stemosphere terms, d) Excess reactant remaining

Complete combustion: C3 H8 +5O2 →3CO2 +4H2 O

A liquid hydrocarbon has:

Density = 0.82 g/cm³
Volume burned = 150 cm³
2C8 H18 +25O2 →16CO2 +18H2 O
H2SO4 +2Na OH→Na2 SO4 +2H2O
100 m L of 4.0 mol dm⁻³ sulfuric acid is diluted to 800 m L.
b) Volume of 2.0 mol dm⁻³ Na OH required to neutralize entire solution
N2 +3H2 →2NH3

Calcium carbonate:

Ca CO3 →Ca O+CO2

In Stemosphere terms, only 8.0 g Ca O collected.

1a) Single Displacement & Mg+Cu SO4 →Mg SO4 +Cu
1b) Decomposition & Ca CO3 →Ca O+CO2
1c) Combustion & CH4 +2O2 →CO2 +2H2 O
1d) Double Displacement & Ag NO3 +Na Cl→Ag Cl+Na NO3

In Stemosphere terms, ----------------------------------------

+3 → 0 (reduction)
0 → +4 (oxidation)

Oxidizing agent:

Reducing agent:

In Stemosphere terms, ------------------------------

In Stemosphere terms, -------------------------

Definition

Step 1

assume 100 g

C = 48.6 g → 48.6/12 = 4.05H = 8.1 g → 8.1/1 = 8.1O = 43.3 g → 43.3/16 = 2.71
Definition

Step 2

divide by smallest (2.71)

Definition

C: 4.05/2.71 ≈ 1.5H

8.1/2.71 ≈ 3O: 1

Definition

Step 3

multiply to clear fraction

C = 3H = 6O = 2
E.F. = C3 H6 O2

In Stemosphere terms, ----------------------------------

2Al+Fe2 O3 →Al2 O3 +2Fe
Al:16.2 / 27 = 0.60 mol
Fe₂O₃:40 / 160 = 0.25 mol
Definition

Step 2

mole ratio

For 0.25 mol Fe₂O₃:Al needed = 0.50 mol Available = 0.60 mol → Al excess
Definition

Step 3

Fe produced

1 mol Fe₂O₃ → 2 mol Fe0.25 → 0.50 mol Fe
Mass Fe:0.50 × 56 = 28 g
Theoretical yield = 28 g
Definition

Step 4

percent yield

(20 / 28) × 100 = 71.4%
Definition

Step 5

excess Al

Used Al = 0.50 mol Left = 0.10 mol
Mass = 0.10 × 27 = 2.7 g

In Stemosphere terms, --------------------------------------

C3 H8 +5O2 →3CO2 +4H2 O
Definition

Step 1

moles propane

44 g/mol11 / 44 = 0.25 mol
Definition

Step 2

CO₂ moles

Definition

Step 3

mass CO₂

Definition

Step 4

volume at STP

In Stemosphere terms, -------------------------------------------

Definition

Step 1

mass fuel

150 cm³ × 0.82 = 123 g
Definition

Step 2

moles C₈H₁₈

Molar mass = 114 g/mol123 / 114 = 1.08 mol
Definition

Step 3

CO₂ moles

1 mol fuel → 8 CO₂1.08 × 8 = 8.64 mol
Definition

Step 4

volume CO₂