Question 1: Transition metals are known for forming compounds that display a range of vibrant colors. This color arises due to d-d electronic transitions when light is absorbed by the electrons in the metal's d-orbitals. These absorbed wavelengths correspond to specific colors, making these compounds visually distinctive.

Answer: Colors in transition metal compounds are caused by d-d electronic transitions that absorb specific wavelengths of light, resulting in the observed color.

Question 1: Define the term 'complex ion' as it relates to transition metal compounds.

Answer: A complex ion is a charged species formed when a transition metal ion bonds with one or more ligands through coordinate covalent bonds.

Question 2: Explain why some transition metal compounds are colored while others are colorless.

Answer: Colored transition metal compounds have partially filled d-orbitals that allow electronic transitions when light is absorbed, whereas colorless compounds typically have fully filled or empty d-orbitals that do not absorb visible light.

Question 1: A solution of a transition metal complex absorbs light at a wavelength of 520 nm. Using Beer-Lambert Law (A = εcl), if the molar absorptivity (ε) is 1.2 x 10^4 L·mol^−1·cm^−1 and the path length (l) is 1 cm, what is the absorbance (A) when the concentration (c) is 2 x 10^−4 mol/L?

Answer: A = (1.2 x 10^4) * (2 x 10^−4) * 1 = 2.4

Question 1: Describe a basic experimental procedure to determine the concentration of a colored transition metal complex in solution using spectrophotometry. Mention key variables to control and safety precautions.

Answer: Prepare a series of standard solutions with known concentrations of the complex. Use a spectrophotometer to measure their absorbance at the compound's characteristic wavelength. Plot a calibration curve of absorbance versus concentration. Measure the absorbance of the unknown sample and use the calibration curve to find its concentration. Control variables include wavelength, path length, and temperature. Safety precautions involve wearing protective goggles, gloves, and working in a well-ventilated area to handle chemicals safely.

Question 1: A student observes that adding chloride ions to a solution of a transition metal ion causes a color change from violet to yellow. Explain the likely reason for this change based on coordination chemistry principles.

Answer: The chloride ions displace other ligands and form a different complex that absorbs different wavelengths of light, resulting in a color change from violet to yellow.

Question 1: Describe one industrial or technological application of colored transition metal compounds, explaining how their color is utilized.

Answer: Colored transition metal compounds are used in dyes and pigments for textiles and paints due to their vibrant colors. For example, chromium-based pigments are used in manufacturing durable and vivid paints.

Question 1: Write a brief summary explaining why transition metal compounds are often vividly colored and how this property is useful in scientific and industrial contexts.

Answer: Transition metal compounds are vividly colored because of d-d electronic transitions that absorb specific wavelengths of light. These colors are useful in various applications such as pigments, indicators, and sensors in industry, as well as in scientific analysis like spectrophotometry.