Calculate the mass of ammonia (NH,) that contains a million (1.00 x 10°) hydrogen atoms.

In the following scenario, identify which of the statements represents a theory, law, or hypothesis. (a) A student exploring the properties of gases proposes that is she decreases the volume of a sample of gas then the pressure exerted by the sample will increase (b) Many scientists over time have conducted similar experiments and have concluded that pressure and volume are inversely proportional. (c) She proposes that the reason this occurs is that if the volume is decreased, more molecules will collide with a given area of the container walls, causing the pressure to be greater.

Write the ordinary form of the following numbers: a 2.32 x 10-2, b 9.27 x 104 c 8.96 x 10-4

1-89 Consider butter, density 0.860 g/mL, and sand, density 2.28 g/mL. (a) If 1.00 mL of butter is thoroughly mixed with 1.00 mL of sand, what is the density of the mixture? (b) What would be the density of the mixture if 1.00 g of the same butter were mixed with 1.00 g of the same sand?

Hexane (C6H14, density = 0.766 g/cm3), perfluoro-hexane (C6F14, density = 1.669 g/cm3), and water are immiscible liquids; that is, they do not dissolve in one another. You place 10 mL of each in a graduated cylinder, along with pieces of high-density polyethylene (HDPE, density = 0.97 g/cm3), polyvinyl chloride(PVC, density = 1.36 g/cm3), and Teflon (density = 2.3 g/cm3). None of these common plastics dissolves in these liquids. Describe what you expect to see.

Molecular distances are usually given in nanometers (1 nm = 1 109 m) or in picometers (1 pm = 1 1012 m). However, the angstrom () unit is sometimes used, where 1 = 1 1010 m. (The angstrom unit is not an SI unit.) If the distances between the Pt atom and the N atom in the cancer chemotherapy drug cisplatin is 1.97 , What is this distances in nanometers? In picometers?

In e-ach of the following pairs, which has the greater mass? (See Table 1.5.) a. 1.0 kg of feathers or 1.0 kg of lead b. 1.0 mL of mercury or 1.0 mL of water c. 19.3 mL of water or 1.00 mL of gold d. 75 mL of copper or 1.0 L of benzene

1.89 Imagine that you place a cork measuring 1.30cm4.50cm3.00cm in a pan of water. On top of this cork, you place a small cube of lead measuring 1.15 cm on a side. Describe how you would determine if the combination of the cork and lead cube will still float in the water. Note any information you would need to look up to answer the question.

Magnesium chloride is an important coagulant used in the preparation of tofu from soy milk. Its solubility in water at 20C is 54.6 g/100 g. At 80C, its solubility is 66.1 g/100 g. A mixture is made up of 16.2 g of magnesium chloride and 38.2 g of water at 20C. (a) Is the mixture homogeneous? If it is, how many more grams of magnesium chloride are required to make a saturated solution? If the mixture is not homogeneous, how many grams of magnesium chloride are undissolved? (b) How many more grams of magnesium chloride are needed to make a saturated solution at 80C?

At 25 C, the density of water is 0.997 g/cm3, whereas the density of ice at 10 C is 0.917 g/cm3. (a) If a soft-drink can (volume = 250. mL) is filled completely with pure water at 25 C and then frozen at - 10 C, what volume does the ice occupy? (b) Can the ice be contained within the can?