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How many grams of potassium dichromate are required to produce 13 grams acetaldehyde?

Mole, Empirical and Stoichiometry Calculations

Mole Calculations (Determining Avogadro's Number): 1. Calculate the mass of carbon in a diamond that contains 3.33 x 1024 atoms of C. 2. Calculate the mass of chloroform that contains 1,000,000,000,000 molecules of CHCL3. 3. Calculate the number of NaCL formula units in 1.37 g of table salt. 4. Calculate the number of N2 mo


A car gets 9.2 kilometers to a liter of gasoline. Assuming that gasoline is 100% octane (C8H18), which has a density of 0.69 g/cm3, how many liters of air (21% oxygen by volume at STP) will be required to burn the gasoline for a 1250-km trip? Assume complete combustion.

Ultraviolet Radiation in Fluorescence

In the process called fluorescence some substances absorb photons of one kind of radiation (ultraviolet) and give out photons of a different kind, when infrared radiation falls on these materials, visible light is not emitted, why? no further info re fluorescence needed, and which element results if two protons and two neutrons

Balanced chemical equation for biosynthesis

Please help with the following problem. Write the balanced chemical equation for the biosynthesis of ethanol. Label the sucrose and the ethanol in the equation. If you start with one mol sucrose, how many mol ethanol is produced? (Assume complete conversion of sucrose to ethanol.) The density of ethanol is 0.80 g/ml. A

Moles of Sulfur Dioxide

How many moles of Sulfur dioxide are in 1.07 x 10 ^23 molecules of sulfur dioxide? And how many molecules are in 58.1 g of Butane?

Moles in Bromine

How many moles are in 8.50 mL of liquid bromine if the density of bromine is 3.12 g/mL?

Finding the average mass of molecules

What is the average mass in grams of the Cobalt (Co) atom? And how many grams of nitrogen dioxide contain the same number of molecules as 5.00 grams of water?

Molecular Weight by Freezing Point Depression of Solution

A 0.573g sample of a nonvolatile solute is added to 15.6g of napthalene and the mixture warmed until melted. The freezing point of the solution was determined and found equal to 78.1C. The freezing point of naphthalene is 80.2C. How do you find out if the boiling pt and the vapor pressure increases or decreases? How do you

Moles & CO2 and N2 & 3H2 reactions & Matter

A. Considering 3.00 moles of CO2: What is its weight in grams? How many molecules are there. B. Considering the reaction: N2(g) + 3H2(g) → 2NH3(g) Explain why this reaction is spontaneous even though it results in matter being less dispersed

the concentration of Ca^2+

What is the concentration of Ca^2+ (in M) that remains dissolved after addition of .15 mol Ca^2+ and .16 mol C2O4^2- to make a 1.0L aqueous solution? (Ksp= 2.7*10^-9)

Reaction of carbon dioxide with lithium hydroxide

The carbon dioxide that is exhaled by astronauts who are on a space shuttle is scrubbed by pumping the air through canisters of lithium hydroxide, LiOH. The chemical equation for this reaction is: 2LiOH + CO2 --> Li2CO3 + H2O What mass of carbon dioxide can 1.00 kg of lithium hydroxide absorb?

Gas Laws - Volume, Density, and Temperature

1.) The density of liquid nitrogen is 0.808 g/mL at -196 degrees Celsius. What volume of nitrogen gas at STP must be liquefied to make 10.0 L of liquid nitrogen? 2.) Calculate the volume occupied by 2.5 mol of an ideal gas at STP. 3.) A hydrocarbon (compound containing only hydrogen and carbon) was analyzed to be 85.7 mass per

Molarity of Solutions

What is the molarity of nitrate (NO3-) in a solution that was made by adding 54.3 g NaNO3 and 43.5 g of Ca(NO3)2 into 560 mL of water?

Percent by mass composition

While chlorofluorocarbons (CFC) are compounds that seem incredibly useful in industry, they also seem to wreak havoc on the ozone layer. If CFC-211 has a percentage by mass of chlorine of 80.46% and carbon of 10.90%, the rest being fluorine, what is the likely formula for CFC-211?

Mass os a molecule

The mass of one molecule in grams is 2.03 x 10^-22 g, its mass in amu is then?

Percent by mass composition

Bronze is an alloy (a mixture of metals) of copper (Cu) and tin (Sn). A sample of brinze is analysed and found to contain 8.0% tin by mass. Therefore, in this sample, the ratio of copper atoms:tin atoms (Cu/Sn) is


The atmosphere of the planet Argos contains the following atom percentages of the isotopes of argon: 36Ar(atomic mass 35.968 amu), 70.0%, 38Ar (atomic mass 37.963 amu), 20.0% and 40Ar (atomic mass 39.962 amu), 10.0%. The average atomic mass of argon(the atomic mass on the periodic table on Argos) on planet Argos will then be...

Forces in gases and in deep space

1.) How much force is required to inflate a high pressure bicycle tire to 95 pounds per square inch (655 kPa) with a hand pump that has a plunger with an area of 5.0 cm^2? 2.) An object exerts a force of 500. N and sits on an area of 4.5m X 1.5m. Calculate the amount of pressure exerted by the object in torr. 3.) During your t

Chemicals and Temperature

1. How small a change temperature can be detect by touch? How could smaller changes in temperature be detected? 2. What would be expect to observe if KHCO3 reacted with HBr? What test would be performed to identify the product? 3. If a reaction called for a minimum of 0.5 moles of table sugar, C6H12O6, and there was only o

Questions of density and volume

In my lab I determined volumes for two unknown metals by two different methods (displacement in a liquid: V=9ml vs. calculation of all sides: V=8.83 cm3 V=5ml V=4.75 cm3 The volumes are not the same. Which do you believe to be more accurate? Why?

Density Problems

1. The density of an uncooked egg is much less than that of a hard boiled egg. Would it make any difference in this demonstration if the egg was hard boiled? If yes, explain what you would see if the graduated cylinder contained: a) only water b) only salt water c) 1/2 water, 1/2 salt water 2. Would a comparison of a can (

Density of Metals

1. Which is more dense, lead or brass? How it can determine? 2. A sheet of metal has the dimensions 5mm, 25 cm, 55cm and its mass is 14.7kg. Using the densities of metals, can you definitely tell what metal this is? How?

Understanding molar concentrations/volume /equations

1. molar concentration of a liter solution of HCl that has 65 grams of HCl in it? 2. How many grams of NaCl are needed to make a molar solution of 2 liters? 3. How many grams of a glucose are in 1 liter of 10% mass/vloume glucose solns?

Density, Volume

1. Describe two different ways by which you could measure the volume of a small cube. 2. Which is more dense, lead or brass? 3. If the value occupied by a liquid 48mL and the density if 1.2g/mL, what is the mass of the liquid? 4. A recycling plant has chips of hight density poly(ethylene) (HDPE, d=0.92g.mL) used for pla

Dissolving silver bromide in a fixer solution

Solid silver bromide AgBr (s) is removed from the film by dissolving it in an aqueous "fixer" solution containing sodium thiosulfate, Na2S2O3 (aq). This reaction produces NaBr (aq) and Na3Ag(S2O3)2 (aq), which can be rinsed away from the film. A fixer solution is prepared by dissolving 120g Na2S2O3 in enough water to make 4.00 L

Reaction between acrylonitrile, propylene, ammonia, and oxygen

Acrylonitrile (C3H3N (g)) is synthesized by reacting propylene (C3H6 (g)), ammonia (NH3 (g)), and oxygen (O2 (g)), to make C3H3N (g) and H2O (g). Suppose that 1.00 kg C3H6, 1.50 kg NH3, and 2.00 kg O2 are mixed and the reaction proceeds to completion. What mass of each reactant and product is present after the reaction is comple