An organic chemist isolates a  colorless liquid from a petroleum sample.  She places the liquid in a pre-weighed flask and puts the flask in boiling water,  which vaporizes the liquid and fills the flask with gas.  She closes the flask and reweighs it.  She obtains the following data: Volume (V) of flask = 196 ml                   T = 99.1°C                        P= 751 mmHg     mass of flask + gas = 81.5 g                           mass of flask = 78.3 g Calculate the molar mass (in g/mol) of the liquid.

What properties distinguish solids from liquids? Liquids from gases? Solids from gases?

Using Table 1.5, calculate the volume of 25.0 g of each of the following substances at 1 atm. a. hydrogen gas b. water c. iron Chapter 5 discusses the properties of gases. One property unique to gases is that they contain mostly empty space. Explain using the results of your calculations.

True or false? Mixtures always result in a chemical reaction because they consist of two or more substances and thus combine to create a new product.

Confronted with the box shown in the diagram, you wish to discover something about its internal workings. You have no tools and cannot open the box. You pull on rope B, and it moves rather freely. When you pull on rope A, rope C appears to be pulled slightly into the box. When you pull on rope C, rope A almost disappears into the box. a. Based on these observations, construct a model for the interior mechanism of the box. b. What further experiments could you do to refine your model?

Which part of the description of a compound or element refers to its physical properties and which to its chemical properties? (a) Calcium carbonate is a white solid with a density of 2.71 g/cm3. It reacts readily with an acid to produce gaseous carbon dioxide. (b) Gray, powdered zinc metal reacts with purple iodine to give a white compound

58 Magnesium will burn in air to form both Mg3N2 and MgO. What mass of each product would be found if burning a 3.11-g sample of magnesium to completion produces a combined total of 5.09 g of the two products?

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.

A 區 88%1 G € T 9 Q1. An organic chemist isolates a colourless liquid from a petroleum sample. She places the liquid in a flask and puts the flask in a boiling water bath, which vaporizes the liquid and fills the flask with gas. She closes the flask, reweighs it, and obtains the following data: Volume of flask (V) = 213 mL Mass of flask+gas = 78.416 g T=100°C P=754 torr (760 torr in 1 atmosphere) Mass of empty flask = 77.834 g Calculate the molar mass of the liquid, carefully converting to appropriate units, where necessary. (Note: Gas constant; R = 0.082057 L.atm.K'.mol¹) 80 5:38 Wed, 29 May E III III B I U 0 о 29 A+ T + 12▾ E▾ W 閃 == 191 < 0 <

A cylinder with a movable piston contains 2.00 gg of helium, HeHe, at room temperature. More helium was added to the cylinder and the volume was adjusted so that the gas pressure remained the same. How many grams of helium were added to the cylinder if the volume was changed from 2.00 LL to 3.50 LL ? (The temperature was held constant.) Express your answer with the appropriate units.