Question

Complete and balance the following equation:

S(s)+HNO3(aq)→H2SO3(aq)+N2O(g)(acidic solution)

Express your answer as a net chemical equation including phases.

Complete and balance the following equation:

BrO3−(aq)+N2H4(aq)→Br2(l)+N2(g)(acidic solution)

Express your answer as a net chemical equation including phases.

Complete and balance the following equation:

H2O2(aq)+ClO2(aq)→ClO2−(aq)+O2(g)(basic solution)

Answer 1

Complete and balance the following equation in acidic solution:

Notice that it is a reductio-oxidation reaction. The atoms like S and N are changing its oxidation states

We have the half-cell reactions:

We add 3 H₂O molecules at left side to balance the number of oxygen atoms:

The, we add 4 H⁺ ions at right side to balance the number of hydrogen atoms:

To balance the charge, we add 4 electrons at left side:

For the half-cell reaction:

We will apply the same procedure to obtain the balanced half-cell reaction:

If we multiply equation (1) by two and sum to the equation (2), we have the net chemical equation:

Complete and balance the following equation in acidic solution:

Following the same procedure for the previous reaction, we have the half-cell reactions:

If we multiply equation (3) by 2, and equation (4) by 5, and we sum, we have the net chemical equation:

Complete and balance the following equation in basic solution:

We have the half-cell reaction:

To balance the number of hydrogen atoms, we add two H₂O molecules at right side:

To balance both hydrogen and oxygen atoms, we add two hydroxyle ions at left side:

To balance the charge, we add 2 electrons at right side:

For the half-cell reaction:

We just need one electron at left side to balance the charge:

If we multiply equation (6) by two and sum to equation (5), we have the net chemical equation: