The reactants are the substances on the left side, which react and give the products on the right side.
The reactants are Fe and O.
The product is Fe2O3.
The arrow to the right means that the reaction is going in only one direction — the only reaction happening at the moment is that Fe and O are making Fe2O3.
(s) means the substance is in the solid state, and (g) means in a gaseous state (or the substance is a gas in that reaction).
Answer:
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- <u><em>C) How much energy was added to the substance to increase molecule motion? </em></u>
Explanation:
<em>The most relevant question to ask regarding this change</em> must take into account the physical knowledge about matter.
When matter changes from<em> liquid </em>state to <em>gaseous</em> state, a physical change called evaporation, the particles (molecules or atoms) of the <em>pure substance </em>will separate from each other, take up more space and move faster.
<em>Condensation</em> is the opposite to evaporation, thus the option A) is not the most relevant question.
<em>The charge of the particles</em> does not change; so the option B) is not relevant at all.
The particles should gain energy from the surroundings to <em>increase</em> their <em>motion</em> (kinetic energy) when they pass from liquid state, where they move slower, to gas state, where they move faster. Hence, the option<em> C), How much energy was added to the substance to increase molecule motion?</em> , is totally relevant.
Since this is an increase in the <em>kinetic energy of the molecules</em>, the option D) is not relevant.
The reaction between methane gas and chlorine gas to form hydrogen chloride and carbon tetrachloride, all in their gaseous form can be expressed through the chemical reaction below.
CH₄ + 4Cl₂ --> 4HCl + CCl₄
Let us assume that all the involved gases behaves ideally such that each mole of the gas is equal to 22.4 L.
Through proper dimensional analysis, the volume of the produced hydrogen chloride is calculated,
V(HCl) = (1.69 mL CH₄)(1 L CH₄/ 1000 mL CH₄)(1 mol CH₄/22.4 L CH₄)(4 mols HCl/1 mol CH₄)(22.4 L HCl/1 mol HCl)(1000 mL/1 L)
V(HCl) = 6.76 mL
<em>ANSWER: 6.76 mL</em>
