Here are the completed and balanced chemical equations for the synthesis reactions.
1. calcium + oxygen $\rightarrow$ calcium oxide
* Formula: $2\text{Ca} + \text{O}_2 \rightarrow 2\text{CaO}$
2. copper + sulfur $\rightarrow$ copper(II) sulfide
* Formula: $\text{Cu} + \text{S} \rightarrow \text{CuS}$
3. calcium oxide + water $\rightarrow$ calcium hydroxide
* Formula: $\text{CaO} + \text{H}_2\text{O} \rightarrow \text{Ca(OH)}_2$
4. hydrogen + nitrogen $\rightarrow$ ammonia
* Formula: $3\text{H}_2 + \text{N}_2 \rightarrow 2\text{NH}_3$
5. hydrogen + chlorine $\rightarrow$ hydrogen chloride
* Formula: $\text{H}_2 + \text{Cl}_2 \rightarrow 2\text{HCl}$
6. silver + sulfur $\rightarrow$ silver sulfide
*(Note: Silver usually has a +1 charge, so it needs two atoms to balance one Sulfur atom with a -2 charge)*
* Formula: $2\text{Ag} + \text{S} \rightarrow \text{Ag}_2\text{S}$
7. chromium + oxygen $\rightarrow$ chromium(III) oxide
*(Note: Chromium typically forms a +3 ion here, requiring 2 Cr atoms and 3 O atoms)*
* Formula: $4\text{Cr} + 3\text{O}_2 \rightarrow 2\text{Cr}_2\text{O}_3$
8. aluminum + bromine $\rightarrow$ aluminum bromide
*(Note: Aluminum is +3 and Bromine is -1, making the formula $\text{AlBr}_3$)*
* Formula: $2\text{Al} + 3\text{Br}_2 \rightarrow 2\text{AlBr}_3$
9. sodium + iodine $\rightarrow$ sodium iodide
* Formula: $2\text{Na} + \text{I}_2 \rightarrow 2\text{NaI}$
10. hydrogen + oxygen $\rightarrow$ water
* Formula: $2\text{H}_2 + \text{O}_2 \rightarrow 2\text{H}_2\text{O}$
11. aluminum + oxygen $\rightarrow$ aluminum oxide
*(Note: Aluminum is +3 and Oxygen is -2, making the formula $\text{Al}_2\text{O}_3$)*
* Formula: $4\text{Al} + 3\text{O}_2 \rightarrow 2\text{Al}_2\text{O}_3$
Parent Tip: Review the logic above to help your child master the concept of synthesis reaction worksheet.
