Chemistry HW Help

Question

In the titration of 235.0 mL of 0.4000 M HONH2 with 0.2000 M HBr, how many mL of HBr are required to reach the halfway point?

Answer 1

The balanced chemical equation for the reaction between HONH2 and HBr is:

HONH2(aq) + HBr(aq) → NH3(aq) + H2O(l) + Br-(aq)

In the reaction, one mole of HBr reacts with one mole of HONH2 to produce one mole of NH3. The halfway point of the titration is reached when half of the HONH2 has reacted, which corresponds to the point where 0.2000 moles of HBr have been added.

The initial moles of HONH2 in the solution can be calculated as follows:

moles of HONH2 = (0.4000 M) x (0.2350 L) = 0.094 moles

Since one mole of HONH2 reacts with one mole of HBr, 0.094 moles of HBr are required to completely react with all the HONH2.

To reach the halfway point, 0.0470 moles of HONH2 must have reacted. This corresponds to the moles of HBr required to reach the halfway point.

moles of HBr = 0.0470 moles

Finally, the volume of 0.2000 M HBr required to reach the halfway point can be calculated as follows:

volume of HBr = (0.0470 moles) / (0.2000 M) = 0.235 L or 235 mL



Therefore, 235 mL of 0.2000 M HBr are required to reach the halfway point.