Answer:
- <em><u>Option A. </u></em><u><em>2KClO₃ → 2KCl + 3O₂</em></u>
Explanation:
There are five basic general types of chemical reactions:
- Synthesis or combination reaction
- Single replacement reactions
- Double replacement reactions
The given reactions are:
- <u>2KClO₃ → 2KCl + 3O₂</u>
Which is, indeed, a decomposition reaction because the reactant, KClO₃, is a single substance that undergoes a reaction in which it yields two new substances, known as products: KCl and O₂.
- <u>4Na + O₂ → 2Na₂O</u> is a synthesis or combination reaction because two reactants, Na and O₂, combine for the formation of one single new product, Na₂O.
- <u>ZnS + 3 O₂ → 2ZnO + 2SO₂ </u>is a single replacement reaction because oxygen is replacing Zn and S in ZnS to form ZnO and plus SO₂.
- <u>2NaBr + CaF₂ → 2NaF + CaBr₂ </u>is a double replacement reaction because two ions (Br⁻ from NaBr and F⁻ from CaF₂) are exchanging places with other two ions (Na⁺ from NaBr and Ca²⁺ from CaF₂) two form two new ionic compounds (NaF and CaBr₂).
Answer: 122 moles
Procedure:
1) Convert all the units to the same unit
2) mass of a penny = 2.50 g
3) mass of the Moon = 7.35 * 10^22 kg (I had to arrage your numbers because it was wrong).
=> 7.35 * 10^22 kg * 1000 g / kg = 7.35 * 10^ 25 g.
4) find how many times the mass of a penny is contained in the mass of the Moon.
You have to divide the mass of the Moon by the mass of a penny
7.35 * 10^ 25 g / 2.50 g = 2.94 * 10^25 pennies
That means that 2.94 * 10^ 25 pennies have the mass of the Moon, which you can check by mulitiplying the mass of one penny times the number ob pennies: 2.50 g * 2.94 * 10^25 = 7.35 * 10^25.
5) Convert the number of pennies into mole unit. That is using Avogadros's number: 6.022 * 10^ 23
7.35 * 10^ 25 penny * 1 mol / (6.022 * 10^ 23 penny) = 1.22* 10^ 2 mole = 122 mol.
Answer: 122 mol
