Question

the chemical formula for hydrogen fluoride is hf. a chemist determined by measurements that 0.030 moles of hydrogen fluoride participate in a chemical reaction. calculate the mass of hydrogen fluoride that participates. be sure your answer has the correct number of significant digits.

Explanation:

Step1: Find molar mass of HF

The molar mass of H (hydrogen) is approximately 1.01 g/mol and F (fluorine) is approximately 19.00 g/mol. For HF, the molar mass $M = 1.01+ 19.00=20.01$ g/mol.

Step2: Calculate mass

We know that the number of moles $n = 0.030$ mol. Using the formula $m=n\times M$, where $m$ is mass, $n$ is number of moles and $M$ is molar mass. So $m = 0.030\times20.01 = 0.6003$ g.

Step3: Apply significant - figures

The number of moles 0.030 has 2 significant figures. Rounding 0.6003 g to 2 significant figures gives 0.60 g.

Answer:

0.60 g