Answer:
• 1a) BaClO₃(s) → BaCl₂(g) + O₂(g)
• 1b) Cl₂(g) + K₃N(s) → N₂(g) + KCl(s)
• 1c) Na₃N(aq) + Al(BrO₃)₃(aq) → AlN(s) + Na(BrO₃)₃(aq)
• 2a) Calcium hydroxide and hydrogen gas
• 2b) Tin(II) silicate and Lead(IV) permanganate
• 2c) Magnesium oxide and water
• 2d) No product
• 2e) Mercury and iodine
• 2f) Calcium chloride and iodine
• 2g) Strontium phosphite and cesium nitride
• 2h) Carbon dioxide, water, and sulfur dioxide
• 2i) Iron oxide(III) and carbon dioxide
• 2j) Magnesium acetate and hydrogen gas
• 2k) Calcium iodide
Explanation:
1. For each of the following, convert the word equation into a formula equation, BUT do not balance! a) Barium chlorate → Barium chloride + Oxygen
1. Chemical formulas
Barium chlorate:
• It is a salt: an ionic compound. • Barium has oxidation state +2 • Chlorate is the ion ClO₃⁻ • Swap the oxidation numbers to write the subscripts: 2 goes to ClO₃ and 1 goes to Ba • Chemical formula Ba(ClO₃)₂ • It is solid: Ba(ClO₃)₂(s)
Barium chloride:
• It is a salt: an ionic compound • Barium has oxidation state +2 • Chlorine is in oxidation state -1 • Swap the numbers to write the subscripts: 2 goes to Cl and 1 goes to Ba • BaCl₂ • It is solid BaCl₂(s)
Oxygen:
• It is a diatomic gas molecule • O₂(g)
2. Write the unbalanced molecular equation:
• BaClO₃(s) → BaCl₂(s) + O₂(g) b) Chlorine + Potassium nitride → Nitrogen + Potassium chloride
1. Chemical formulas
Chlorine:
• It is a diatomic gas molecule • Cl₂(g)
Potassium nitride
• It is a salt
• Potassium has oxidation state +1 • Nitrogen is with oxidation state +3 • Swap the oxidation states • K₃N • It is solid: K₃N(s)
Nitrogen:
• It is a diatomic gas • N₂(g)
Potassium chloride • It is a salt (ionic compound) • Potassium has oxidation state +1 • Chlorine is in oxidation state -1 • Swap the oxidation numbers • KCl • It is solid: KCl(s)
2. Write the unbalanced molecular equation
• Cl₂(g) + K₃N(s) → N₂(g) + KCl(s) c) Sodium nitride + Aluminum bromate → Aluminum nitride + Sodium bromate
1. Chemical formulas
Sodium nitride
• It is a salt (ionic compound) • Sodium has oxidation state +1 • Nitrogen is with oxidation state -3 • Swap the oxidation numbers • Na₃N • It is in aqueous solution • Na₃N (aq)
Aluminum bromate
• Salt • Aluminum has oxidation state +3 • Bromate is the ion BrO₃⁻ • Swap the oxidation states • Al(BrO₃)₃ (aq)
Aluminum nitride
• Both Al and N have oxidation state 3, which simply • AlN(s). It is not soluble in water.
Sodium bromate
• Na(BrO₃)₃ (aq)
2. Write the unbalanced molecular equation
• Na₃N(aq) + Al(BrO₃)₃(aq) → AlN(s) + Na(BrO₃)₃(aq) 2. For each of the following, predict the products IN WORDS ONLY! a) Calcium + Water →
Caclum is a member of the alkaline earth metals.
Alkaline Earth Metals react with water to produce hydroxides plus hydrogen gas.
Thus, the products when calcium metal reacts with water are calcium hydroxide and hydrogen gas. b) Tin(II) permanganate + Lead(IV) silicate →
This is the reaction between two salts.
The typical reaction of a salt with other salt is a double replacement reaction, in which the ions are swapped.
The general description is salt + salt → salt + salt.
Tin from tin(II) permanganate will replace the lead in lead(IV) silicate and will become tin(II) silicate.
At the same time, the lead from lead(IV) silicate will replace the tin in tin(II) permanganate and become lead(IV) permanganate.
Thus, the products are tin(II) silicate and lead(IV) permanganate. c) Magnesium hydroxide →
There is just one reactant, thus this is a decomposition reaction in which the starting compound forms simpler compounds or elements.
Magnesium hydroxide has chemical formula Mg(OH)₂ and it decomposes into magnesium oxide (MgO) and water (H₂O).
Thus, it is used as the starting point to produce MgO, which has industrial applications. Also, its ability to produce water makes it a good component of some plastics to confer fire retardancy. d) Iron + Sodium oxide →
The only way in which iron, Fe, could react with sodium oxide, Na₂O, is via a displacement or single replacement reaction, in which Fe would replace Na to form Fe₂O₃ or FeO. But, this does not happen because iron is less active than sodium. When you deal with single replacement reactions you must use a table or list with the activity series to learn which element is more active. The reaction will only proceed if a more active element is combined with a compound which has a less active element: only a more active element can displace a less active element from its compound. e) Mercury(I) iodide →
This is a decomposition reaction, in which the mercury(I) iodide decomposes into simpler elements or compounds.
Mercury(I) iodide is Hg₂I₂ it can decompose under certain condition into mercury(II) iodide, HgI₂ and mercury, Hg, but the complete decompositon will lead to the single elements mercury and iodine. f) Calcium iodide + Chlorine →
This is the reaction of a salt with a single element.
If it would proceed it would be via a displacement reaction: the chlorine should replace the iodine from the calcium iodide to produce calcium chloride.
Does this happen? Sure it does: chlorine is more active than iodine, thus the former can displaces the latter.
The final products will be calcium chloride, CaCl₂, and iodine, I₂.
Again, to predict the reaction you need to use a list with the activity series to learn which element is more active and can displace the other. g) Strontium nitride + Cesium phosphite →
This is the reaction between two salts. Thus, this is a double replacement reaction.
Strontium from strontium nitride will replace cesium from cesium phosphite and cesium from cesium phosphite will replace strontium from strontium nitride.
Thus, strontium phosphite and cesium nitride will be formed. h) C₂H₅S + O₂ →
This is not a classical reaction.
The classic reaction is the combustion of hydrocarbon with oxygen to produce carbon dioxide, CO₂, and water, H₂O. Yet, this is an organic compound and the reaction is the combustion of the organic compound. Then, carbon dioxide and water will be formed. Nevertheless, the sulfur, S, atoms will also form an oxide, sulfur oxide (SO₂).
The final products are carbon dioxide, water, and sulfur dioxide. i) c) Iron(III) carbonate →
This is the decomposition of a single compound which will produce simpler constituents.
• Fe₂(CO₃)₃ → Fe₂O₃ + 3CO₂
Thus, the products are iron oxide(III) and carbon dioxide. j) Magnesium + Acetic acid →
The acetic acid is a weak acid. It has one acid hydrogen; thus this is the reaction of a weak acid an a very active metal.
The reaction of a metal and an acid produces the corresponding salt and hydrogen gas.
The salt formed between magnesium and acetic acid is magnesium acetate.
Thus, at the end, magnesium acetate and hydrogen gas will be formed, but in a slow way, since the acid is weak. k) Iodine + Calcium →
This is a combination or synthesis reaction.
In a synthesis reaction, two (or more) simpler substances combine to form a more complex substance, a compound.
In this case, the reactants are two elements (elements are the simplest substances), a nonmetal, iodine, and a metal, calcium.
Calcium is willing to give up its two valence electrons and iodine is willing to accept one electron to complete its valence shell.
Thus, one atom of calcium will combine with two atoms of iodine to form an ionic compound, in which both atoms complete 8 valence electrons in the outermost shell.
The ionic compound formed by one calcium ions and two iodine ions is named calcium iodide.