CHEM 120 Week 2 Discussion 1 - Chemical Names

CHEM 120 Week 2
Discussion 1 - Chemical
Names



SECTION 1: IONIC COMPOUNDS (BINARY)

Question 1
What is the correct name for NaCl?
A. Sodium chlorine
B. Sodium chloride
C. Sodium chlorate
D. Sodium perchlorate

Answer: B. Sodium chloride

Rationale: NaCl is an ionic compound formed from sodium (Na⁺) and chlorine (Cl⁻). The
name is the metal followed by the nonmetal with the "-ide" suffix. Table salt is sodium
chloride.




Question 2

,What is the correct name for KBr?
A. Potassium bromine
B. Potassium bromide
C. Potassium bromate
D. Potassium perbromate

Answer: B. Potassium bromide

Rationale: KBr is formed from potassium (K⁺) and bromine (Br⁻). The nonmetal bromine
becomes bromide with the "-ide" suffix.




Question 3
What is the chemical formula for magnesium oxide?
A. MgO₂
B. Mg₂O
C. MgO
D. Mg₂O₃

Answer: C. MgO

Rationale: Magnesium forms Mg²⁺ and oxygen forms O²⁻. The charges balance 1:1,
giving MgO.




Question 4
What is the chemical formula for calcium chloride?
A. CaCl
B. CaCl₂
C. Ca₂Cl
D. Ca₂Cl₂

Answer: B. CaCl₂

Rationale: Calcium forms Ca²⁺ and chloride forms Cl⁻. The charges balance with one
Ca²⁺ and two Cl⁻ ions: CaCl₂.

, Question 5
What is the correct name for Mg₃P₂?
A. Magnesium phosphate
B. Magnesium phosphide
C. Magnesium phosphorus
D. Trimagnesium diphosphide

Answer: B. Magnesium phosphide

Rationale: Mg₃P₂ is formed from magnesium (Mg²⁺) and phosphorus (P³⁻). The
nonmetal phosphorus becomes phosphide with the "-ide" suffix.




Question 6
What is the chemical formula for aluminum sulfide?
A. AlS
B. AlS₂
C. Al₂S₃
D. Al₃S₂

Answer: C. Al₂S₃

Rationale: Aluminum forms Al³⁺ and sulfide forms S²⁻. The charges balance with two
Al³⁺ (+6) and three S²⁻ (-6): Al₂S₃.




Question 7
What is the correct name for CaO?
A. Calcium dioxide
B. Calcium oxide