Question

exam lesson name: chemistry
exam number: 700700rr
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question 3 of 20 :
select the best answer for the question.

1. examine the following unbalanced chemical equation: co₂ + c → co. which of the following is the correctly balanced form of this equation?

○ a. 2co₂ + c → co
○ b. co₂ + c₂ → co
○ c. co₂ + c → c₂o
○ d. co₂ + c → 2co

□ mark for review (will be highlighted on the review page)

Explanation:

Step1: Analyze reactants and products

Reactants: \( \text{CO}_2 \) (1 C, 2 O) and \( \text{C} \) (1 C), total C: 2, O: 2.
Products: \( \text{CO} \) (1 C, 1 O) initially.

Step2: Balance atoms

• Carbon: Reactants have 2 C (1 from \( \text{CO}_2 \), 1 from \( \text{C} \)). Products need 2 C, so \( \text{CO} \) coefficient should be 2 (2 C, 2 O).
• Oxygen: Reactants have 2 O (from \( \text{CO}_2 \)). Products (2 \( \text{CO} \)) have 2 O. Balanced.

Check option D: \( \text{CO}_2 + \text{C}
ightarrow 2\text{CO} \).
Reactants: C = 1 + 1 = 2, O = 2.
Products: C = 2, O = 2. Balanced.

Answer:

D. \( \text{CO}_2 + \text{C}
ightarrow 2\text{CO} \)