Question

1. which of the following is chemical property of iodine? (3pts)

□ blue black color
□ shiny crystals
□ sharp odor
□ corrosive vapor

1. in the following reaction 35.50 g of reactant was used. if 32.88 g of hg was produced, how much o₂ was also formed?

2hgo(s) → 2 hg(l) + o₂(g)

Explanation:

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Question 21

Physical properties are observable without chemical change; chemical properties describe reactivity/behavior during chemical change. Blue-black color, shiny crystals, sharp odor are physical (observable without altering iodine's chemical structure). Corrosive vapor describes iodine's chemical reactivity (it damages materials via chemical reactions).

Step1: Apply Law of Conservation of Mass

The total mass of reactants equals total mass of products. Let $m_{\text{O}_2}$ = mass of oxygen.
$m_{\text{HgO}} = m_{\text{Hg}} + m_{\text{O}_2}$

Step2: Rearrange to solve for $m_{\text{O}_2}$

Substitute given masses into the equation.
$m_{\text{O}_2} = m_{\text{HgO}} - m_{\text{Hg}}$
$m_{\text{O}_2} = 35.50\ \text{g} - 32.88\ \text{g}$

Answer:

$\square$ blue black color
$\square$ shiny crystals
$\square$ sharp odor
$\checkmark$ corrosive vapor

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Question 22