We know that 0.0300 moles of hydrogen participate in a chemical reaction and we must calculate the mass
In order to calculate the mass we must use the next formula
[tex]\text{ mass}=\text{ molar mass}\cdot\text{ number of moles}[/tex]
In this case, the number of moles is given, 0.0300 moles and the molar mass of the hydrogen is 1.00784 g/mol
Now, we must replace the values in the formula
[tex]\text{ mass}=1.00784\frac{g}{mol}\cdot0.0300mol[/tex]
Finally, we must simplify the equation
[tex]\text{ mass}=0.0302352g[/tex]
Using the correct significant digits,
[tex]\text{ mass}=3.02\cdot10^{-2}g[/tex]
ANSWER:
[tex]3.02\cdot10^{-2}[/tex]
