Balancing Chemical Reaction Equations │Please Help!

Question

1.‎ Drag and drop the coefficients to balance this equation:

___C₆H₆ + ___O₂ ==> ___CO₂ + ___H₂O

2.‎ Magnesium (Mg) reacts with oxygen (O₂) producing magnesium oxide (MgO).

a. Write the skeleton reaction equation (just show reactants and products with the arrow.)

b. Balance the chemical reaction.

c. Classify the type of chemical reaction this is.

Answer 1

1.‎ balance this equation

___C₆H₆ + ___O₂ ==> ___CO₂ + ___H₂O

Here's a reasonable approach:

1. Balance C and H by adding coefficients 6 for CO₂ and 3 for H₂O

___C₆H₆ + ___O₂ ==> 6 CO₂ + 3 H₂O

2. Count total O atoms on the right (15) and put half that number (7.5)

as the coefficient for O₂. This gives the balanced equation

C₆H₆ + 7.5 O₂ ==> 6 CO₂ + 3 H₂O

3. If you're required to have all coefficients be integers, then double all coefficients in step 2

This gives the new balanced equation

2 C₆H₆ + 15 O₂ ==> 12 CO₂ + 6 H₂O

2.‎ Magnesium (Mg) reacts with oxygen (O₂) producing magnesium oxide (MgO).

a. Write the skeleton reaction equation (just show reactants and products with the arrow.)

Mg + O₂ ==> MgO

b. Balance the chemical reaction.

Mg + ½O₂ ==> MgO is a balanced equation

If you're required to all coefficients be integers, then double all coefficients to give

2Mg + O₂ ==> 2MgO which is also a balanced equation

c. Classify the type of chemical reaction this is.

Since Mg is oxidized (Mg⁰ loses 2 electrons to become Mg²⁺)

and O is reduced (O⁰ gains 2 electrons to become O^2–)

I would say the chemical reaction type is redox