Surface chemistry Questions and Answers

Pick the odd one out. Stirring Increase in surface area Increase in pressure Decrease in temperature

Calcium and magnesium ion from a 105 litre sample of hard water was quantitatively precipitated as carbonates and weight of ppt obtained was found to be 568 g. Precipitate lost 264 g of weight on strong heating (A) Degree of hardness of water is 4 ppm (B) Molarity of Ca2+ ions in hard water was 4 x 10-5 M (C) Molarity of Mg2+ ions in hard water was 4 x 10-5 M (D) Sum of molarity of Ca2+ and Mg2+ ions in hard water was 6 x 10-5 M

A substance has a higher temperature when its particles have a higher average kinetic energy. Imagine two different substances that are both pure, meaning they each contain only on type of matter. Each substance has a different temperature. Which two properties determine which substance has the higher temperature?

9) Show the correct link according to description on the right: a) Hypotonic b) Isotonic c) Suspension d) Osmosis e) Dialysis f) Solution Solution has a lower solute concentration as the concentration inside the blood cells (1 point) A homogeneous mixture made up of very small size molecules or ions. Passage of water molecules through a semi-permeable membrane from a solution containing a lower salt concentration to a solution containing a higher salt concentration Small molecules and ions pass through a semi-permeable membrane while large macromolecules are held back Heterogeneous mixture with very large and heavy particles that tend to settle down on the bottom of the container. Solution has the same solute concentration as the concentration inside the blood cells

If you added 35.5 ml of an HCl solution to 35.5 ml of an NaOH solution and the temperature increased from 25.5 °C to 36.5 °C how much heat transferred in this process? The density of the mixture is 1.00 g/ml.

Match the terms about analytical precipitations to their definitions. The adsorption, occlusion, or inclusion of impurities along with the desired analyte in a precipitate. The binding of impurities to the surface of a crystal. The inclusion or occlusion of impurities within a crystal. The process of letting a precipitate stand with the mother liquor to promote slow recrystallization. The process of breaking up of a precipitate upon washing with water in the absence of an electrolyte.

Micelles consist of milk proteins and other molecules suspended in water. a soluble form of vitamin D. aggregates of alcohol molecules. None of these responses is correct. a broken-down form of vitamin D. water-soluble fat molecules.

An oxygen (O₂) molecule is adsorbed on a patch of surface (see sketch at right). This patch is known to contain 289 adsorption sites. The (0₂) molecule has enough energy to move from site to site, so it could be on any one of them. Suppose additional surface becomes exposed, so that 484 adsorption sites are now available for the molecule. Calculate the change in entropy. Round your answer to 3 significant digits, and be sure it has the correct unit symbol.

Identify the improved version of the sentence below. Learning how to knit can be a relaxing and therapeutic activity. It is a good idea for children to learn to knit in school. Some might argue that learning how to knit can be a relaxing and therapeutic activity. However, it is a good Idea for children to learn to knit in school. Learning how to knit, therefore, can be a relaxing and therapeutic activity. For this reason, it is a good idea for children to learn to knit in school. Learning how to knit can be a relaxing and therapeutic activity. It is a good idea for children to learn to knit in school. All of the choices

A sample of water is mixed with a surfactant. What will most likely happen to the viscosity of the water? Explain your answer.

The forces between water molecules are stronger than the forces between ethanol molecules. Which liquid would probably be most difficult for an insect to walk on? Explain your answer.

Describe two uses of surfactants. At least one must be something that was not described in the passage. For each example, explain how the effects of the surfactant make it useful.

A student places a small amount of water in a glass dish and then carefully places a small paperclip on the surface of the water. The paperclip floats. What happens if the student adds a drop or two of dish soap to the water? Explain your answer.

When oil is placed in water, oil is insoluble soluble solvent

is useful to separate mixtures of colored compounds. Spectrometry Electromagnetism Chromatography

What is a watershed? Which watershed do you live in? When it rains at your home, what creek and river does the water travel to?