The chemical formula for magnesium sulfide is MgS A chemist determined by measurements that 0.025 moles of magnesium sulfide participate in a chemical reaction. Calculate the mass of magnesium sulfide that participates Round your answer to 2 significant digits C-1
The Correct Answer and Explanation is :
To calculate the mass of magnesium sulfide (MgS) that participates in the chemical reaction, we need to follow these steps:
Step 1: Identify the molar mass of magnesium sulfide (MgS)
The molar mass of a compound is the sum of the atomic masses of the elements it contains, multiplied by their respective quantities.
- Magnesium (Mg) has an atomic mass of approximately 24.31 g/mol.
- Sulfur (S) has an atomic mass of approximately 32.07 g/mol.
Thus, the molar mass of magnesium sulfide (MgS) is:
[
\text{Molar mass of MgS} = 24.31 \, \text{g/mol (Mg)} + 32.07 \, \text{g/mol (S)} = 56.38 \, \text{g/mol}.
]
Step 2: Use the given moles to calculate the mass
We are given that 0.025 moles of magnesium sulfide (MgS) participate in the reaction. To find the mass of MgS, we use the following relationship between moles and mass:
[
\text{Mass} = \text{Moles} \times \text{Molar mass}
]
Substituting the values:
[
\text{Mass of MgS} = 0.025 \, \text{mol} \times 56.38 \, \text{g/mol} = 1.4095 \, \text{g}.
]
Step 3: Round the answer to 2 significant digits
Since the given number of moles, 0.025 moles, has 2 significant digits, we round the calculated mass to 2 significant digits:
[
\text{Mass of MgS} \approx 1.4 \, \text{g}.
]
Conclusion:
The mass of magnesium sulfide (MgS) that participates in the chemical reaction is approximately 1.4 grams.
Explanation:
The calculation involved converting moles of a substance (magnesium sulfide) to its mass by multiplying the number of moles by the substance’s molar mass. This is a standard stoichiometric calculation in chemistry. We also rounded the final result to match the precision of the given data, which was provided to two significant digits. This ensures that the answer reflects the correct level of uncertainty inherent in the original measurement.