Answer: 0.0164 molar concentration of hydrochloric acid in the resulting solution.
Explanation:
1) Molarity of 0.250 L HCl solution: 0.0328 M
The amount of HCl in the 0.250 L solution = 0.0082 moles
2) Molarity of 0.100 L NaOH solution: 0.0245 M
The amount of NaOH in the 0.100 L solution = 0.00245 moles
3) Determining the concentration of hydrochloric acid in the final solution.
0.00245 moles of NaOH will neutralize 0.00245 moles of HCl from the original 0.0082 moles of HCl.
The total volume of the mixture becomes 0.100 L + 0.250 L = 0.350 L
Remaining moles of unreacted HCl = 0.0082 moles - 0.00245 moles = 0.00575 moles
Concentration of the remaining HCl:
0.0164 molar concentration of hydrochloric acid in the resulting solution.
The correct choice is C. It prohibits the exploitation of mineral resources.
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>
In this case, to find the grams of sodium chloride starting from its molecules, the first step is to determine the moles of sodium chloride by utilizing Avogadro's number. After that, we can obtain grams directly using the molar mass of sodium chloride (58.45 g/mol).
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.
