General Questions and Answers

3 The photograph at the right shows two penguins of the same species displaying different feather color patterns The newly discovered all black penguin had only black feathers since emerging from the egg The sudden appearance of this characteristic was most likely due to a an increase in sun exposure for the penguin chick b deposition of oil on the feathers due to pollution c a random change in the sequences of bases in DNA d a change in the diet of the penguin chick Source http green yahoo com blog guest blogs 24 al black penguin discovered

6 mol C H6 1 X 13 mol C H6 7 mol O 2 mol C H6 2 C2H6 7O2 4 CO2 6 H2O A problem asks how many moles of oxygen gas are needed to react completely with 6 moles of ethane C2 H6 What is the final answer for this problem 21 mol O2 3 mol O2 42 mol O

Formula Name Submit b Write the formula and name for the conjugate partner for BrO3 Formula

The greatest hazard in steel erection is a lack of sufficient training b failure to use proper PPE when needed c falls from higher to lower levels d improper rigging procedures

Which of the following representations and explanations for silicon are correct 4s 3s 2p 1 2s 1 D 1 B 2 b C 4 4s 3p 35 2p 1 25 1s c 45 3p 3s 2p 2s 1s 1 d 80 45 2p 1 All of the electrons have their own orbital 2 All of the electrons are paired 3 Electrons start filling the first energy level first and fill in order 4 Highest energy electrons occupy their own orbital first 2 1s 1

Complete and balance the given precipitation reactions including the physical states of the products as pre the solubility rules AgNO aq NaBr aq 1 K PO aq MgCl aq Examine the precipitation reactions to determine whether each of the involved species is oxidized reduced or neither Oxidized Reduced Neither

In the equation 2 Al2O3 4 Al 3 O2 what is the mole ratio of aluminum to oxygen

A student makes a graph of ionization energy using the periodic table IONIZATION ENERGY EV 30 25 20 10 in O HELIUM lonization Energy O EV NEON 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 ATOMIC NUMBER 30 EV ARGON What would you predict as the approximate ionization energy of Krypton

The yttrium 88 nuclide radioactively decays by electron capture Write a balanced nuclear chemical equation that describes this process Y

15 Diagram the acid base reaction with conj base conj Acid base acid 2 pts SO4 H30 HSO4 H O

Enzymes can be classified into six major groups according to the type of reaction they catalyze 1 Oxidoreductases catalyze oxidations and reductions 2 Transferases catalyze the transfer of a group of atoms 3 Hydrolases catalyze hydrolysis reactions 4 Lyases catalyze the addition of two groups to a double bond or the removal of two groups from adjacent atoms to create a double bond 5 Isomerases catalyze isomerization reactions 6 Ligases or synthetases catalyze the joining of two molecules On the basis of the classification given above decide to which group each of the following enzymes belongs Acetylcholinesterase b Creatine kinase H H CH3 0 C C N CH3 CH3 Acetylcholine H N CH3 O N NH O H O This is a an ATP Adenosine H C C OH Acetic acid ADP Adenosine CH3 H H HO C C N CH CH3 Choline CH3 O P NH2 O

EXERCISE Protein Structure 1 What is the name of the highlighted bond Make sure to include the word bond in your answer 1 www H COOH k

omplete and balance the equation for this single displacement reaction Phases are optional balanced equation Sr HBr O

a The osmotic pressure is proportional to the molar concentration of the sucrose solution Calculate the molarity of the sucrose solution Osmotic Pressure 1 79 atm

Complete each statement with the correct term shows lowest whole number ratio of atoms of each element found in a compound shows the number of atoms of each element found in one molecule of the compound A molecular formula An empirical formula Some formulas could be either molecular or empirical formulas however some can only be molecular formulas Which of the formulas must be molecular formulas C H O4 C H O NO PO

7 Combustion reactions are a notable source of carbon dioxide in the environment Using the following balanced equation how many grams of carbon dioxide are formed when 100 00 g of propane C3H8 is burned Express your answer to the correct number of significant figures Be sure to show all steps completed to arrive at the answer C3H8 50 3C02 4H O

Determine the num Mg Cations Mg2 Mg of Mg Anions Answer Bank Mg Mg Mg PO his requ What is the formula for the ionic compound PO PO PO PO PO

What is the empirical formula of a compound composed of 24 5 g of potassium K and 5 01 g of oxygen O Insert subscripts as needed

Complete and balance the equation for the single displacement reaction between lithium and magnesium chloride Phase are optional balanced equation Li s MgCl aq

Which of the following is TRUE of a system for which Keq 1 none of the above O The equilibrium favors the forward reaction It will take a short time to reach equilibrium It will take a long time to reach equilibrium The equilibrium favors the reverse reaction

For the each element convert the given mole amount to grams How many grams are in 0 0164 mol of potassium mass How many grams are in 0 150 mol of nickel mass How many grams are in 0 790 mol of argon

Determine the number of Al and CI ions required to form a neutral ionic compound Cations Al Al AP k Anions Answer Bank AP AP AP 6 What is the formula for the ionic compound 66 CI Cr CI

Determine the number of Na and SO4 ions required to orm a Nat Cations Na Na Nat Nat Nat Anions Answer Bank So 2 2 SO SO 2 What is the formula for the ionic compound 2 So SO 2 So 2

Write the chemical formula for the compound formed by each pair of positive and negative ions Ba and NO Al and CO

What is the empirical formula of a compound composed of 3 25 hydrogen H 19 36 carbon C and 77 39 oxygen 0 by mass Insert subscripts as needed

Write the nuclear symbol for the neutral atom shown nuclear symbol Nucleus 3 protons 4 ncutrons 3

Exactly 1 mol Ba NO3 2 contains how many moles of Ba N and O moles of Ba moles of N I

What is the formula for copper II phosphate Capitalization and punctuation count formula How many atoms of phosphorus are in 2 10 mol of copper II phosphate of Patoms

Determine which diagram best represents the ionic compound Na CO3 dissolved in wate O 2

A 10 83 g sample of NaBr contains 22 34 Na by mass Considering the law of constant composition definite proportions now many grams of sodium does a 8 57 g sample of sodium bromide contain

Tin has 10 stable isotopes The heaviest 124Sn makes up 5 80 of naturally occurring tin atoms How many atoms of 124Sn are present in 41 0 g of naturally occurring tin atoms of 124Sn What is the total mass of the 124Sn atoms in this sample

What is the mass of exactly 1 mole of each of the elements osmium TOOLS X10

A reaction produces 0 815 moles of H O How many molecules of H O are produced

14 3CaCl2 aq 2Na3 PO4 aq Ca3 PO4 2 s 6NaCl aq aboon dearl saussed nopyxo el 3nsase prijenil sd Molar Mass E 2 250 00 Substance g mol HIT PRVSPR mulasngs lite moon orld bns besa CaCl2 mulang 110 0 o 163 9 12 Ainsbud2 plecu Na3 PO4 Ca3 PO4 2 mil 310 2sb yidomos insbusa binw I insbut2 A Sinabuja s 3 57 8 grams of IGO NaCl 58 44 Use the balanced equation and the Molar Mass table above to answer the following question How many moje buse a i Assuming 163 9 g of Na3 PO4 in solution is mixed with sufficient CaCl2 find the theoretical yield of Ca3 PO4 using the chemical reaction above ii Upon conducting the experiment the solution actually yields 116 g of Ca3 PO4 2 s What the percent yield of Ca3 PO4 2 s

A marine biologist is preparing a deep sea submersible for a dive The sub stores breathing air under high pressure in a spherical air tank that measures 63 0 cm wide The biologist estimates she will need 8400 L of air for the dive Calculate the pressure to which this volume of air must be compressed in order to fit into the air tank Write your answer in atmospheres Be sure your answer has the correct number of significant digits

came dripping terrified and horror stricken at the sight that I hid myself in a closet and da long after the bloody transaction was over I expected it would be my turn me I had never seen any thing like it before I had always lived with my outskirts of the plantation where she was put to raise the children of the y therefore been until now out of the way of the bloody scenes that off plantation What was the chief offense by Aunt Hester according to the master Going out with Lloyd Ned Being late to work Eating too much Resting for more hours

1 HYPOTHESIS the Predict which gasses in the earth s atmosphere will absorb re radiate most infrared energy Rank each gas on a scale from 1 5 with 1 absorbing re radiating the most and 5 absorbing re radiating the least Provide a brief explanation for your prediction gas explanation

If a mini van gets 33 miles per gallon on average how much carbon dioxide is emitted into the atmosphere when the mini van travels 310 miles Express your answer rounded to the nearest tenth of a pound of carbon dioxide lb of CO

A solution of ethanol and water is prepared by mixing 3 92 g of pure ethanol with 25 39 g of pure water The mole fraction of water in the resulting solution is Please report mole fraction to 4 significant figures An aqueous solution of KBr contains 2 31 m KBr aq The density of the solution is 1 165 g mL What is the molarity of KBr in this solution Please report molarity to 3 significant figures Answer

7 What can you conclude about the transparency of the earth s atmosphere with regards to visible energy

A 305mL sample of oxygen gas is collected over water and the total pressure measured to be 856 0mmHg What is the pressure in mmHg of the dry oxygen gas if the vapor pressure of water at the collection temperature is 18 5mmHg If needed R 0 0821 L atm K mole and 1 000atm 760 0mmHg mmHg

A 23 7 mL sample of 0 372 M dimethylamine CH3 NH is titrated with 0 348 M hydroiodic acid After adding 9 40 mL of hydroiodic acid the pH is Use the Tables link in the References for any equilibrium constants that are required

he samarium 147 nuclide radioactively decays by alpha emission Write a balanced nuclear chemical equation that describes this process 11 X Y C

A chemist designing an airbag is looking at carbon dioxide as a possible gas for inflation One of the reactions the chemist is working with is MgCO3 s MgO s CO2 g How many grams of magnesium carbonate MgCO3 are needed to produce enough carbon dioxide CO to inflate an airbag to a volume of 65 0 liters HINT Assume the volume is all CO grams MgCO3

What mass in grams of potassium chloride KCI is produced if 2 43 X 1024 formula units of potassium chlorate KCIO3 decomp according to the reaction given grams KCI

6H 0 C6H12O6 60 The average human requires 120 0 grams of glucose C6H1206 per day You might remember the equation for the production of photosynthesis from biology How many liters of CO are required for this amount of glucose liters of CO

1 Balance each of the following chemical equations a Ca OH 2 HCl CaCl H O Ca OH a 2 HC1 C C1 CaCl aq b Al Pb NO3 2 A1 NO3 3 Pb 2A1 s 3Pb NO3 2Ad c NH4 2SO4 KOH K SO4 NH3 H O

Na3PO4 BaClz Ba3 PO4 2 NaCl How many moles of BaCl are needed to make 2 50 moles of NaCI

Use the reaction below to answer the following questions Use the factor label method shown in the notes Na O H O 2NaOH a How many moles of NaOH are produced from 120 grams of Na 0 b How many grams of Na O are required to produce 3 5 moles of NaOH POSSIBLE POIN moles NaOH grams Na O

My car has an internal volume of 2600 liters If the sun heats my car from a temperature of 10 C to a temperature of 40 C what will the pressure inside my car be Assume the pressure was initially 760 mm Hg