Question

use with textbook pages 256-267.
types of chemical reactions—word equations
classify each of the following chemical reactions as synthesis (s), decomposition (d), single replacement (sr), double replacement (dr), or neutralization (n). then write a balanced equation for each word equation.
_______ 1. magnesium + sulphur → magnesium sulphide
_______ 2. potassium hydroxide + sulphuric acid → water + potassium sulphate
_______ 3. chlorine + potassium iodide → potassium chloride + iodide
_______ 4. aluminum chloride + sodium hydroxide → aluminum hydroxide + sodium chloride
_______ 5. lead(ii) oxide → lead + oxygen
_______ 6. magnesium + silver nitrate → silver + magnesium nitrate
_______ 7. cadmium(ii) nitrate + ammonium sulphide → cadmium(ii) sulphide + ammonium nitrate
_______ 8. tin(iv) hydroxide + hydrogen bromide → water + tin(iv) bromide
_______ 9. sodium + oxygen → sodium oxide
_______10. sodium nitride → sodium + nitrogen

Explanation:

1. Reaction Classification

Two reactants form one product (synthesis).

1. Balancing

Atoms of Mg, S are equal on both sides.

2. Reaction Classification

Acid + base → salt + water (neutralization).

2. Balancing

Balance K, H, O by adding coefficients 2, 2.

3. Reaction Classification

One element replaces another (single replacement).

3. Balancing

Balance Cl, K, I by adding coefficients 2, 2.

4. Reaction Classification

Ions swap partners (double replacement).

4. Balancing

Balance Al, Cl, Na, OH by adding coefficients 3, 3.

5. Reaction Classification

One reactant breaks into two products (decomposition).

5. Balancing

Balance Pb, O by adding coefficients 2, 2.

6. Reaction Classification

One element replaces another (single replacement).

6. Balancing

Balance Ag, NO3 by adding coefficient 2.

7. Reaction Classification

Ions swap partners (double replacement).

7. Balancing

Balance Cd, S, NH4, NO3 by adding coefficient 2.

8. Reaction Classification

Acid + base → salt + water (neutralization).

8. Balancing

Balance Sn, OH, H, Br by adding coefficient 4.

9. Reaction Classification

Two reactants form one product (synthesis).

9. Balancing

Balance Na, O by adding coefficients 4, 2.

10. Reaction Classification

One reactant breaks into two products (decomposition).

10. Balancing

Balance Na, N by adding coefficients 2, 6.

Answer:

1. S; $\ce{Mg + S -> MgS}$
2. N; $\ce{2KOH + H2SO4 -> 2H2O + K2SO4}$
3. SR; $\ce{Cl2 + 2KI -> 2KCl + I2}$
4. DR; $\ce{AlCl3 + 3NaOH -> Al(OH)3↓ + 3NaCl}$
5. D; $\ce{2PbO -> 2Pb + O2↑}$
6. SR; $\ce{Mg + 2AgNO3 -> 2Ag + Mg(NO3)2}$
7. DR; $\ce{Cd(NO3)2 + (NH4)2S -> CdS↓ + 2NH4NO3}$
8. N; $\ce{Sn(OH)4 + 4HBr -> 4H2O + SnBr4}$
9. S; $\ce{4Na + O2 -> 2Na2O}$
10. D; $\ce{2Na3N -> 6Na + N2↑}$