Liquid hexane (CH₂(CH₂) CH₂) v will react with gaseous oxygen (0₂) to produce gaseous carbon dioxide (CO₂) and gaseous water (11₂0). Suppose 7.8 g of hexane is mixed with 53.6 g of oxygen. Calculate the minimum mass of hexane that could be left over by the chemical reaction. Round your answer to 2 significant digits. 6 X S

A 0.755-g sample of hydrated copper(II) sulfate CuSo4xH2O was heated carefully until it had changed completely to anhydrous copper(II) sulfate (CuSO4 ) with a mass of 0.4183 g. Determine the value of x. [This number is called the number of waters of hydration of copper(II) sulfate. It specifies the number of water molecules per formula unit ofCuSO4 in the hydrated crystal.]

You have a pure sample of apholate, C12H24N9P3, a highly effective commercial insecticide. Calculate the molar mass of apholate. Calculate the mass of N in 100. g apholate. A sample containing 250.0 mg apholate is sprayed on an agricultural field. Calculate the mass of phosphorus in this sample of apholate; express your result in grams. Calculate the number of phosphorus atoms in this sample of apholate.

A 12.1-g sample of Na2SO3 is mixed with a 14.6-g sample of MgSO4. What is the total mass of oxygen present in the mixture?

4-102 Aspartame, an artificial sweetener used as a sugar substitute in some foods and beverages, has the molecular formula C14H18N2O5. (a) How many mg of aspartame are present in 3.72 × 1026 molecules of aspartame? (b) Imagine you obtain 25.0 mL of aspartame, which is known to have a density of 1.35 g/mL. How many molecules of aspartame are present in this volume? (c) How many hydrogen atoms are present in 1.00 mg of aspartame? (d) Complete the skeletal structure of aspartame, where all the bonded atoms are shown but double bonds, triple bonds, and/or lone pairs are missing. (e) Identify the various types of geometries present in each central atom of aspartame using VSEPR theory. (f) Determine the various relative bond angles associated with each central atom of aspartame using VSEPR theory. (g) What is the most polar bond in aspartame? (h) Would you predict aspartame to be polar or nonpolar? (i) Is aspartame expected to possess resonance? Explain why or why not. (j) Consider the combustion of aspartame, which results in formation of NO2(g) as well as other expected products. Write a balanced chemical equation for this reaction. (k) Calculate the weight of C02(g) that can be prepared from 1.62 g of aspartame mixed with 2.11 g of oxygen gas.

Copper reacts with nitric acid according to the following reaction. 3Cu(s)+8HNO3(aq)3Cu(NO3)2(aq)+2NO(g)+4H2O(l) If 2.40 g of Cu is added to a container with 2.00 mL of concentrated nitric acid (70% by mass HNO3; density = 1.42 g/cm3), what mass of nitrogen monoxide gas will be produced?

High-density lipoprotein (HDL) cholesterol is the good cholesterol because adequate levels reduce the risk of heart disease and stroke. HDL levels between 40. and 59 mg/dL are typical for a healthy individual. What is this range of HDL cholesterol in units of mol/L? The formula for cholesterol is C27H46O.

89 A number of compounds containing the heavier noble gases, and especially xenon, have been prepared. One of these is xenon hexafluoride (XeF6), which can be prepared by heating a mixture of xenon and fluoride gases. XeF6 is a white crystalline solid at room temperature and melts at about 325 K. A mixture of 0.0600 g of Xe and 0.0304 g of F2 is sealed into a 100.0-mL bulb. (The bulb is heated, and the reaction goes to completion. Then the sealed bulb is cooled back to 20.0°C. What will be the final pressure in the bulb, expressed in torr?

There are five hydrocarbon compounds (compounds of C and II) that have the formula C6H14. (These are isomers; they differ in the way that C and H atoms are attached. Chapter 23) All are liquids at room temperature but have slightly different densities. (a) You have a pure sample of one of these hydrocarbons, and to identify it you decide to measure its density. You determine that a 5.0-mL sample (measured in a graduated cylinder) has a mass of 3.2745 g (measured on an analytical balance). Assume that the accuracy of the values for mass and volume is plus or minus one ( 1) in the last significant figure. What is the density of the liquid? (b) Can you identify the unknown hydrocarbon based on your experiment? (c) Can you eliminate any of the five possibilities based on the data? If so, which one(s)? (d) You need a more accurate volume measurement to solve this problem, and you redetermine the volume to be 4.93 mL Based on this new informationwhat is the unknown compound?

The present average concentration (mass percent) of magnesium ions in seawater is 0.13%. A chemistry textbook estimates that if 1.00 × 108 tons Mg were taken out of the sea each year, it would take one million years for the Mg concentration to drop to 0.12%. Do sufficient calculations to either verify or refute this statement. Assume that Earth is a sphere with a diameter of 8000 mi, 67% of which is covered by oceans to a depth of 1 mi, and that no Mg is washed back into the oceans at any time.