Question

a compound is found to contain 10.85 % silicon, 27.40 % chlorine, and 61.75 % bromine by mass. what is the empirical formula for this compound? to answer the question, enter the elements in the order presented above. siclbr an error has been detected in your answer. check for typos, miscalculations etc. before submitting your answer. 9 more group attempts remaining. use the references to access important values if needed for this question. submit answer retry entire group

Explanation:

Step1: Assume 100g of the compound

Since the percentages are by mass, if we assume 100g of the compound, we have 10.85g of Si, 27.40g of Cl, and 61.75g of Br.

Step2: Calculate the moles of each element

The molar mass of Si is approximately 28.09 g/mol, so the moles of Si, $n_{Si}=\frac{10.85g}{28.09g/mol}\approx0.386mol$. The molar mass of Cl is approximately 35.45 g/mol, so the moles of Cl, $n_{Cl}=\frac{27.40g}{35.45g/mol}\approx0.773mol$. The molar mass of Br is approximately 79.90 g/mol, so the moles of Br, $n_{Br}=\frac{61.75g}{79.90g/mol}\approx0.773mol$.

Step3: Find the mole - ratio

Divide each number of moles by the smallest number of moles (0.386 mol). For Si: $\frac{0.386mol}{0.386mol} = 1$. For Cl: $\frac{0.773mol}{0.386mol}\approx2$. For Br: $\frac{0.773mol}{0.386mol}\approx2$.

Answer:

SiCl₂Br₂