turquoisecat367

One liter CO reacts with one litre of gives only one liter . Which law is followed this reaction?

What is water?

Bromine has two naturally occurring isotope of Br-79 and Br-81 if the relative atomic mass of bromine 80, calculate the relative abudance of each isotope.

Write down the digit in the hundredths place in this number 48.253

a) An electron in a 3s-orbital is (lower or higher) in energy than an electron in a 2s-orbital.

b) An electron in a 2s-orbital is (lower or higher) in energy than an electron in a 2p-orbital.

c) A metal typically (loses or gains its valence electron(s)) becoming a(n) (cation or anion).

How can the different techniques of protein isolation and purification take advantage of the differences in the molecular weight, size, effective charge, solubility, acid-base behavior, or specific affinity of the protein against that of the contaminating biomolecules?

1. All scientists use the (_____), which is based on multiples of 10. 

2. (____) is an important physical property used to identify, sort, and describe objects. There are many possible answers for this since it is not very much specified, I would suggest texture, shape, and color for starters. We may use other measurements like density for these tasks, too. 

3. The amount of space matter takes up, or (_____) is measured in different ways for different objects.

4. (_______) is a measure of the pull of gravity on an object. 

5. Where would a person weigh the least, Denver International or Ohare International?

6. Where would the person have the least amount of mass?

7. Where would the person weigh the most, Laguardia or New Orleans International?

The technique of protecting metal from accelerated corrosion by connecting it to a different metal that is more easily oxidized, i.e. the sacrificial anode, is called cathodic
protection. It's not necessary to cover the entire surface of the metal to be protected with the second, more easily oxidized metal. All that's required is electrical contact with the second, sacrificial metal. An underground steel pipeline, for example, can be protected by connecting it through an insulated wire to the sacrificial anode. Cathodic protection runs out when the sacrificial anode is completely consumed or the connection between the two dissimilar metals is broken. Which of the four metals below offers cathodic protection to the iron in the steel pipe? (Remember, steel is iron plus a small percentage of carbon.)

a)Zn

b) Ni

c) Al

d) Sn

Many people have 900 MHz phones which refer to the frequency of radiation it uses to communicate.

What energy does this correspond to (in joules/photon)?

What is this energy in kJ/mol?

What wavelength does this correspond to?

Write isotopic symbols of the form (e.g., ) for each isotope.

You analyzed 2.475g  of a mixture of , and . You isolate .825g , .825g of and .580 g . You were told that the original mixture contained 35% , 45% and 20% . Calculate, compare, and offer an explanation for the differences in the composition of of , , and you recovered. Explain.

Find the length of 1 side of a cubic box if its volume is 40 gal.

Deuterium is an isotope of hydrogen. The abundance of deuterium in water is 0.0150%. How many moles of water would be required to obtain 0.0730 moles of deuterium (D2)?

Write the short-hand and long-hand electron configuration for eachof the following ions. For each ion, identify another ion that is isoelectronic with it.
a)

b)  

c)  

Determine whether each process is exothermic or endothermic and indicate the sign of ΔH.

a) Dry ice evaporating

b) a sparkler burning

c) the reaction that occurs in a chemical cold pack often used to ice athletic injuries

Describe how a normal AA battery stores and conducts electrons into useful energy.

You have 141.0 g of solute Q dissolved in 130-mL of water. The distribution coefficient between ether and water for solute Q is 7. What volume of ether would you need to extract 123.0 g of solute Q in one extraction from the original 141.0g dissolved in 130 mL water? Provide answer to closest mL. (Show calculations)

Consider the following reaction

When the system is at equilibrium, it contains at a pressure of 0.825 atm and at a pressure of 0.0681 atm. The volume of the container is then reduced to half its original volume. What is the pressure of each gas after equilibrium is reestablished?

You inherit a gold bar that measures 7.0 inches by 3.0 inches by 2.0 inches. How many ounces does the bar weigh? The density of gold is .

Phosphorus pentachloride decomposes according to the chemical equation 

at  

A 0.2713 mol sample of is injected into an empty 3.30 L reaction vessel held at . Calculate the concentrations of and  at equilibrium.

The atomic number of an atom defines its identity. However, it is the configuration of the electrons surrounding the nucleus that determines the chemical behavior of an atom. Examine the following electron configurations, then group them in pairs that would indicate similar chemical properties of the corresponding atoms. Then, explain in your own words, why your paired atoms would have similar chemical properties.

a) 1s²2s²2p⁶3s²

b) 1s²2s²2p³

c) 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶

d) 1s²2s²

e) 1s²2s²2p⁶

f) 1s²2s²2p⁶3s²3p³

Mixtures of helium and oxygen are used in scuba diving tanks to help prevent "the bends". For a particular dive, 18.6 L of oxygen gas at and 1.79 atm, and 7.55 L of helium gas at and 2.68 atm were pumped into a tank with a volume of 6.00 L at . 

Calculate (in atm):

1. the partial pressure of oxygen

2. the partial pressure of helium

3. the total pressure in the tank at 

Carbon monoxide gas reacts with water vapor to produce carbon dioxide gas and hydrogen gas. In an experiment, 0.500 mole of each component was added to a 1.00-L container. If K=23.2 for this reaction, calculate the equilibrium position.

Consider the following liquids with similar molar masses. Predict which has the strongest intermolecular attraction based only on vapor pressure data.

liquid	vapor pressure
a) acetic acid	14 mm Hg at
b) butane	1550 mm Hg at
c) isopropyl alcohol	35 mm Hg at
d) ethyl methyl ether	1260 mm Hg at
e) ethyl chloride	1050mm Hg at

How many of the following molecules are polar? Show the Lewis structures.

a)  

b)  

c)  

d)  

What would the volume of air inside a 35.0L tire under 244 kPa of pressure occupy if it escaped to standard atmospheric conditions?

What is the wavelength of a proton traveling at a speed of 6.57 km/s?

Using electron configuration, explain the bonding patterns of the following elements.

(a) Alkali metals

(b) Halogens

(c) Group 15 or nitrogen family

Write the net ionic equation for  

an explanation that accounts for a set of facts is best known as a

A scuba diver 40 ft below the ocean surface inhales 75.0 mL of compressed air from a scuba tank at a pressure of 3.10 atm and a temperature of . What is the pressure of the air, in atm, in the lungs when the gas expands to 175.0 mL at a body temperature of , and the amount of gas remains constant?

What kind of intermolecular forces act between an argon atom and a hydrogen molecule?

Dinitrogen pentoxide is a product of the reaction between and . Balance the equation below for this reaction and calculate the theoretical yield of if 79.9 g of is reacted with an excess of .

Rank the following atoms in order of increasing metallic character: Strontium (Sr), Francium (Fr), Sodium (Na) and Calcium (Ca)

Calculate the energy, in joules, required to excite a hydrogen atomby causing an electric transition from the n=1 to the n=4 principal energy level.

a.  

b.

c.  

d.  

a) How are the electron configurations of fluorine (F) and chlorine (Cl) are similar?

b) How are they different? 

c) How do you expect the electron configurations of bromine (Br) and iodine (I) to be similar to those of fluorine and chlorine?

What is the relationship between wavelength and the penetrating power of an electromagnetic wave?

In the Kr atom (in its ground state), how many electrons are l = 1 and m = 0?

The reaction between limestone and hydrochloric acid produces carbon dioxide as shown in the reaction: (unbalanced) How many grams of can be made by reacting 125 g of with 125 grams of HCl? How many grams of which reactant will be left over? - enter only your numeric answer, do not use scientific notation, and enter 3 significant digits.