when magnesium and hydrochloric acid reacted, (rate of reaction), what would you have to do to express the average reaction rate in terms of mass of magnesium consumed per second and in terms of moles of magnesium reacted per second..thnks..
To express the average reaction rate of the magnesium and hydrochloric acid reaction in terms of mass of magnesium consumed per second, you need to follow these steps:
Step 1: Determine the change in mass of magnesium.
Measure the initial mass of the magnesium before the reaction and record it as m_initial. Then, measure the final mass of the magnesium after the reaction and record it as m_final. Calculate the change in mass as Δm = m_initial - m_final.
Step 2: Determine the time taken for the change in mass.
Measure the time taken for the reaction to occur and record it as t.
Step 3: Calculate the average rate of reaction in terms of mass.
Divide the change in mass (Δm) by the time taken (t) to obtain the average rate of reaction in terms of mass consumed per second:
Average rate of reaction (in terms of mass) = Δm / t
To express the average reaction rate in terms of moles of magnesium reacted per second, you need to consider the stoichiometry of the chemical equation. The equation for the reaction between magnesium and hydrochloric acid is as follows:
Mg(s) + 2HCl(aq) -> MgCl2(aq) + H2(g)
From the balanced equation, you can see that 1 mole of magnesium reacts with 2 moles of hydrochloric acid. Therefore, every mole of magnesium consumed corresponds to the production of 1 mole of hydrogen gas.
Step 1: Determine the moles of magnesium consumed.
Calculate the moles of magnesium consumed using the equation:
moles of magnesium consumed = mass of magnesium consumed / molar mass of magnesium
Step 2: Determine the time taken for the moles of magnesium consumed.
Use the same time measurement recorded in Step 2 above.
Step 3: Calculate the average rate of reaction in terms of moles.
Divide the moles of magnesium consumed by the time taken to obtain the average rate of reaction in terms of moles of magnesium consumed per second:
Average rate of reaction (in terms of moles) = moles of magnesium consumed / t
By following these steps, you can express the average reaction rate in terms of both mass of magnesium consumed per second and moles of magnesium reacted per second.