The Chemical Formula For Calcium Sulfide Is Cas. A Chemist Measured The Amount Of Calcium Sulfide Produced During An Experiment. She Finds That 172.G Of Calcium Sulfide Is Produced. Calculate The Number Of Moles Of Calcium Sulfide Produced. Be Sure Your Answer Has The Correct Number Of Significant Digits. 4.76 Mol 1.19 Mol 7.82 Mol None Of The Options are correct
2.38 mol
The Correct Answer and Explanation is :
determine the number of moles of calcium sulfide (CaS) produced from a mass of 172 grams, we can use the relationship between mass, molar mass, and moles, which is given by the formula: ext{Number of moles} = \frac{\text{Mass (g)}}{\text{Molar mass (g/mol)}} ]
p 1: Calculate the Molar Mass of Calcium Sulfide (CaS)
The mor mass of a compound is the sum of the molar masses of its constituent elements. For caium sulfide:
- Calcm () has an atomic mass of approximately 40.08 g/mol.
- Sulfur h an atomic mass of approximately 32.06 g/mol.
Adding thesother gives:
Molarsof CaS=40.08 g/mol+32.06 g/mol=72.14 g/mol\text{Molarsof CaS} = 40.08\, \text{g/mol} + 32.06\, \text{g/mol} = 72.14\, \text{g/mol}
Step 2: Calculathe Number of Moles
Using the mass provid (172 g) and the molar mass calculated:
\text{Number of ms= \frac{172\, \text{g}}{72.14\, \text{g/mol}} \approx 2.384\, \text{mol}
Step 3: Consider Signcant Figures
The given mass (172 g) has ree significant figures. Therefore, our final answerhould also be expressed with three significant figures:
Number of moles\px2.38 mol\text{Number of moles} \px 2.38\, \text{mol}
Conclusion
Based on the culation, 172 gra of calcium sulfide corresponds to approximately 2.38 moles. Among the provided options, the cct answer is 2.38 mol.
Explanation
In chemistry, it’ssential to converbetween mass and moles to understand the quantities of substances involved in reactions. The molar mass serves as a bridge betwthe mass of a substance and the amount in moles. By dividing the mass of the sample by itlar mass, we obtain the number of moles, which allows chemists to predict how substances will react in given proportions.
Significant figures are crucial in scientcalculations as they convey the precision of the measured values. When performing calculations, the result shoue reported with the same number of significant figures as the least precise measurement to ensure that the reported precision reflects the precision of the input data.
In this problem, the mass of calcium sulfide wpvided with three significant figures (172 g), so the final answer for the number of moles was appropriately rounded to three significant figures, resulting in 2.38 mol.