Question

instructions
balance each chemical equation below. students may work four.

1. $\ce{h_{2} + o_{2} -> h_{2}o}$

answer:

1. $\ce{n_{2} + h_{2} -> nh_{3}}$

answer:

1. $\ce{c + o_{2} -> co_{2}}$

answer:

1. $\ce{fe + o_{2} -> fe_{2}o_{3}}$

answer:

1. $\ce{mg + o_{2} -> mgo}$

answer:

1. $\ce{al + o_{2} -> al_{2}o_{3}}$

answer:

1. $\ce{ca + o_{2} -> cao}$

answer:

1. $\ce{na + cl_{2} -> nacl}$

answer:

1. $\ce{k + br_{2} -> kbr}$

answer:

1. $\ce{zn + hcl -> zncl_{2} + h_{2}}$

answer:

1. $\ce{fe + hcl -> fecl_{2} + h_{2}}$

answer:

Explanation:

Step1: Balance H₂ + O₂ → H₂O

Balance O first: add 2 to H₂O, then add 2 to H₂.
$2\text{H}_2 + \text{O}_2
ightarrow 2\text{H}_2\text{O}$

Step2: Balance N₂ + H₂ → NH₃

Balance N first: add 2 to NH₃, then add 3 to H₂.
$\text{N}_2 + 3\text{H}_2
ightarrow 2\text{NH}_3$

Step3: Balance C + O₂ → CO₂

Atoms are already balanced.
$\text{C} + \text{O}_2
ightarrow \text{CO}_2$

Step4: Balance Fe + O₂ → Fe₂O₃

Balance O first: add 2 to Fe₂O₃, 3 to O₂; then add 4 to Fe.
$4\text{Fe} + 3\text{O}_2
ightarrow 2\text{Fe}_2\text{O}_3$

Step5: Balance Mg + O₂ → MgO

Balance O first: add 2 to MgO, then add 2 to Mg.
$2\text{Mg} + \text{O}_2
ightarrow 2\text{MgO}$

Step6: Balance Al + O₂ → Al₂O₃

Balance O first: add 2 to Al₂O₃, 3 to O₂; then add 4 to Al.
$4\text{Al} + 3\text{O}_2
ightarrow 2\text{Al}_2\text{O}_3$

Step7: Balance Ca + O₂ → CaO

Balance O first: add 2 to CaO, then add 2 to Ca.
$2\text{Ca} + \text{O}_2
ightarrow 2\text{CaO}$

Step8: Balance Na + Cl₂ → NaCl

Balance Cl first: add 2 to NaCl, then add 2 to Na.
$2\text{Na} + \text{Cl}_2
ightarrow 2\text{NaCl}$

Step9: Balance K + Br₂ → KBr

Balance Br first: add 2 to KBr, then add 2 to K.
$2\text{K} + \text{Br}_2
ightarrow 2\text{KBr}$

Step10: Balance Zn + HCl → ZnCl₂ + H₂

Balance Cl/H first: add 2 to HCl.
$\text{Zn} + 2\text{HCl}
ightarrow \text{ZnCl}_2 + \text{H}_2$

Step11: Balance Fe + HCl → FeCl₂ + H₂

Balance Cl/H first: add 2 to HCl.
$\text{Fe} + 2\text{HCl}
ightarrow \text{FeCl}_2 + \text{H}_2$

Answer:

1. $2\text{H}_2 + \text{O}_2

ightarrow 2\text{H}_2\text{O}$

1. $\text{N}_2 + 3\text{H}_2

ightarrow 2\text{NH}_3$

1. $\text{C} + \text{O}_2

ightarrow \text{CO}_2$

1. $4\text{Fe} + 3\text{O}_2

ightarrow 2\text{Fe}_2\text{O}_3$

1. $2\text{Mg} + \text{O}_2

ightarrow 2\text{MgO}$

1. $4\text{Al} + 3\text{O}_2

ightarrow 2\text{Al}_2\text{O}_3$

1. $2\text{Ca} + \text{O}_2

ightarrow 2\text{CaO}$

1. $2\text{Na} + \text{Cl}_2

ightarrow 2\text{NaCl}$

1. $2\text{K} + \text{Br}_2

ightarrow 2\text{KBr}$

1. $\text{Zn} + 2\text{HCl}

ightarrow \text{ZnCl}_2 + \text{H}_2$

1. $\text{Fe} + 2\text{HCl}

ightarrow \text{FeCl}_2 + \text{H}_2$