Question

writing and balancing chemical equations
quiz complete
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which chemical equation is unbalanced?
c + o₂ → co₂
sr + o₂ → 2sro
6h₂ + 3o₂ → 6h₂o
h₂ + h₂ + o₂ → h₂o + h₂o

Explanation:

Step2: Count right Sr atoms
Right Sr count: $2$

Step3: Count left O atoms

Left O count: $2$

Step4: Count right O atoms

Right O count: $2$

Step5: Identify unbalanced equation

Sr atoms are unequal, so this equation is unbalanced.

Step6: Verify balanced equations

• $\text{C} + \text{O}_2

ightarrow \text{CO}_2$: 1C, 2O on both sides.

• $6\text{H}_2 + 3\text{O}_2

ightarrow 6\text{H}_2\text{O}$: 12H, 6O on both sides.

• $\text{H}_2 + \text{H}_2 + \text{O}_2

ightarrow \text{H}_2\text{O} + \text{H}_2\text{O}$: 4H, 2O on both sides.

Answer:

Step2: Count right Sr atoms
Right Sr count: $2$

Step3: Count left O atoms

Left O count: $2$

Step4: Count right O atoms

Right O count: $2$

Step5: Identify unbalanced equation

Sr atoms are unequal, so this equation is unbalanced.

Step6: Verify balanced equations

• $\text{C} + \text{O}_2

ightarrow \text{CO}_2$: 1C, 2O on both sides.

• $6\text{H}_2 + 3\text{O}_2

ightarrow 6\text{H}_2\text{O}$: 12H, 6O on both sides.

• $\text{H}_2 + \text{H}_2 + \text{O}_2

ightarrow \text{H}_2\text{O} + \text{H}_2\text{O}$: 4H, 2O on both sides.