1) To find the molar mass of C6H8O6, you must refer to the atomic weights of C, H, and O from the periodic table: C is 12; H is 1; O is 16 <span> (12x6)+(1x8)+(16x6)= 176g/mol
</span> <span> 176 g = 1 mol
0.5 g = x mol = 500 mg = 0.5 grams
Molar mass = mass ÷ moles
176 = 0.5 ÷ x
x = 2.84 x 10⁻³ mol
2) To calculate the total number of molecules in those </span> 2.84 x 10⁻³ mol, multiply the moles by <span> Avogadro's constant.
Number of molecules = Avogadro's constant x number of moles
Number of molecules = 6.022 x 10²³ x 2.84 x 10⁻³ </span> = 1.71 x 10²¹ molecules of vitamin C. <span>
</span>
extinction coefficient (ε) = 347 L·mol⁻¹·cm⁻¹. The chemical equation representing the reaction of chromium (Cr) with hydrochloric acid (HCl) is: 2 Cr + 6 HCl → 2 CrCl₃ + 3 H₂. To find the number of moles, we apply the formula: number of moles = mass / molar weight. For chromium, we calculate: number of moles of Cr = 0.3 × 10⁻³ (g) / 52 (g/mole), leading to number of moles of Cr = 5.77 × 10⁻⁶ moles. Examining the reaction, we observe that 2 moles of Cr yield 2 moles of CrCl₃, hence 5.77 × 10⁻⁶ moles of Cr will also produce 5.77 × 10⁻⁶ moles of CrCl₃. The molar concentration is determined by: molar concentration = number of moles / volume (L), thus molar concentration of CrCl₃ = 5.77 × 10⁻⁶ / 10 × 10⁻³, which equals 5.77 × 10⁻⁴ moles/L. To convert percent transmittance (%T) to absorbance (A), we use the equation A = 2 - log(%T). Therefore, A = 2 - log(62.5), leading to A = 0.2. The relationship defining absorbance (A) includes the extinction coefficient (ε), path length (l), and concentration (c): A = εlc, hence ε = A / lc, giving ε = 0.2 / (1 × 5.77 × 10⁻⁴), which results in ε = 0.0347 × 10⁴. Thus, the extinction coefficient is ε = 347 L·mol⁻¹·cm⁻¹.
Answer:
are present in solution.
Explanation:
Molarity of the solution = 0.210 M
Volume of the solution = 65.5 ml = 0.0655 L
Moles of aluminum iodide = n
n = 0.013755 moles of aluminum iodide
Each mole of aluminum iodide yields 3 moles of iodide ions:
Thus, 0.013755 moles of aluminum iodide will provide:
moles of iodide ions
The total number of iodide ions in 0.041265 moles:
are present in solution.
