Question

b.4 calculate the number of moles of h₂ that are expected to form in each flask based on the number of moles of mg that will react and the equation for each reaction. (1 mole of h₂ is produced for every mole of mg reacted.)
a. the flask with 0.3 g mg
b. the flask with 0.6 g mg
c. the flask with 1.2 g mg

Explanation:

Step1: Calculate moles of Mg

Use the formula \(n=\frac{m}{M}\), where \(n\) is the number of moles, \(m\) is the mass, and \(M\) is the molar mass. The molar mass of \(Mg\) is \(M = 24.31\space g/mol\).

For part a:

\(n_{Mg}=\frac{0.3\space g}{24.31\space g/mol}\approx0.0123\space mol\)
Since \(1\) mole of \(H_2\) is produced for every mole of \(Mg\) reacted, \(n_{H_2}=n_{Mg}\)

For part b:

\(n_{Mg}=\frac{0.6\space g}{24.31\space g/mol}\approx0.0247\space mol\)
Since \(1\) mole of \(H_2\) is produced for every mole of \(Mg\) reacted, \(n_{H_2}=n_{Mg}\)

For part c:

\(n_{Mg}=\frac{1.2\space g}{24.31\space g/mol}\approx0.0494\space mol\)
Since \(1\) mole of \(H_2\) is produced for every mole of \(Mg\) reacted, \(n_{H_2}=n_{Mg}\)

Answer:

a. \(0.0123\space mol\)
b. \(0.0247\space mol\)
c. \(0.0494\space mol\)