General Questions and Answers

13 2 points What is the weight percent of carbon in C10H16N OgNa4 31 3 O 25 34 0 33 3 Previous

18 2 points CH3NH2 would be classified as a weak acid strong acid Ostrong base weak base Previous

11 2 points Bleach splatter on a pair of jeans leaves white spots Is this a chemical or physical change Chemical Physical Previous

Balance the half reaction in basic solution Use e as the symbol for an elect

7 2 points Identify the conjugate acid in the following reaction H O N H4 H O N H5 OH30 OH 0 ON H5 N H4

2 Consider the following balanced chemical equation CaC2 s 2H2O 1 Ca OH 2 s C2H2 g If 2 0 g of CaC2 are completely reacted with water to give 2 0 g of Ca OH 2 what is the percent yield of Ca OH 2 The formula masses of CaC2 and Ca OH 2 are 64 1and 74 1 respectively

4 The alkane heptane C7H16 is designated as the zero point in the octane rating of gasoline Heptane is an undesirable compound in gasoline because it burns rapidly and causes engine knocking How many grams of O are required to react with 22 50 g of C7H16 O2 C7H16 CO2 H O

7 When 45 0 grams of copper II carbonate are decomposed with heat how many grams of carbon dioxide will be produced 8 How many grams of water can be produced from 56 9 grams of hydrogen and 23 9 grams of oxygen

It dissociates into ions when it dissolves in water Identify the formula including the charge of the ions that are formed from its dissociation Tap an option to select or deselect the cation and anion Cation Choices Fe 2 Fe Fe Fe3 Fe Anion Choices SO4 SO4 SO34 SO4 SO4 View Polyatomic lon List

5 Write the molecular equation and then net ionic equation for a the neutralization of hydrocyanic acid HCN by lithium hydroxide in aqueous solution b the neutralization of hydrobromic acid with calcium hydroxide solution

1 On a space shuttle LiOH is used to absorb exhaled CO2 from breathing air to form LiHCO3 What is the percent yield of LiHCO3 for the reaction if 50 0 g of LiOH gives 72 8 g of LiHCO3 LiOH s CO g LiHCO3 s

5 Complete the table below with either a Lewis structure or a line angle drawing Compound Name diethyl ketone methyl propanoate H H C H Lewis Structure H C O H C H H H H Line Angle Drawing

Suppose you need 6 0 m of Grade 70 tow chain which has a diameter of 3 8 and weighs 2 16 kg m to tow a car How would you calculate the mass of this much chain Set the math up But don t do any of it Just leave your answer as a math expression Also be sure your answer includes all the correct unit symbols mass of chain

3 Which is the most accurate thing to say about the data in the graph below Atmospheric Carbon Dioxide Levels 400 375 350 325 300 275 250 225 200 175 Atmospheric Carbon Dioxide Vostok Ice Core Law Dome Ice Core Mauna Loa Instrumental Measurements 400 000 300 000 200 000 Years Before Present 5 points Current Level MA 100 000 The amount of CO2 in the atmosphere has never changed until very recently Atmospheric CO2 levels go through a cycle of about 50 000 years The current levels of CO2 in the atmosphere are far higher than we would expect from analyzing past cycles

For given pair of compounds identify which compound is the stronger base and explain your choice A B Bis the stronger base because the nitrogen atom has a localized lone pair A is the stronger base because the nitrogen atom has a localized lone pair A is the stronger base because the nitrogen atom has a delocalized lone pair Bis the stronger base because the nitrogen atom has a delocalized lone pair Neither base is stronger because they are both tertiary amines

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1 The graph below represents a substance being heated from 30 C to 110 C Heating Curve Temperature C D 110 90 70 50 30 10 10 30k 0 50 100 150 200 250 300 350 400 450 Energy Absorbed kJ SED If 50 kJ of heat are removed the state and temperature of the substance A gas at 70 C B gas at 100 C C liquid at 0 C liquid at 10 C from the substance when it is at 50 C what will be REL

Mn NO3 3 molar mass of compound 54 93 Mn N 0 3 10 lithium phosphide Li P molar mass of compound 51 8 Li 43202 P 799 Me NH4 2 0 compos

2 points The negative log of the hydroxide ion concentration is called the pOH pH H OH O O O Previous

dissociates into ions when it dissolves in water Identify the formula including the charge of the ions that are formed from its dissociation Tap an option to select or deselect the cation and anion Cation Choices NH4 N H NHA2 NH4 NH 4 Anion Choices Br 4 Br Br Br Br4 View Polyatomic lon List

1 The chemical reaction of carbon monoxide and hydrogen is used to produce methanol CH3OH If 3 00 mol of CO and 5 00 mol of H are the initial reactants how many moles of methanol can be produced and what is the limiting reactant CO g 2H2 g CH3OH 2 When silicon dioxide sand and carbon are heated the products are silicon carbide SiC and carbon monoxide Silicon carbide is a ceramic material that tolerates extreme temperatures and is used as an abrasive and in the brake discs of sports cars How many grams of CO are formed from 70 0 g of SiO2 and 50 0 g of C SIO2 s SIC s C CO g

2 points Select all items that are a property of an EXOthermic reaction Energy is absorbed Feel a decrease in temperature Requires less activation energy than endothermic reactions Takes more energy to break reactants bonds than form products bonds Takes more energy to form products bonds than to break reactants bonds Energy is released Requires more activation energy than endothermic reactions Feel an increase in temperature

3 5 6 37 38 39 40 41 42 43 45 2 points An atom that gains electrons in a chemical reaction is the reducing agent has been oxidized has been redoxed is the oxidizing agent Previous

A reaction was predicted to produce 32 4 grams of a compound When the product was measured only 26 1 grams were produced What is the percent yield of this react

P4 HNO3 H3PO4 NO 1 H O 25 ml of 2 M HNO3 is used for this reaction The mixture is treated with 30 ml 0 5 M NaOH solution Find pH of mixture Mixture does not contain any P4 left pKa of H3PO4 2 12 pKa of H3PO4 7 21 pKa3 of H3PO4 12 67 0721 9 33

3 A sample of gas is heated from 317 K to 428 K If its initial pressure was 983 torr what will be its final pressure Need Know Formula Solve

8 2 points A bag of water softener salt contains 40 lb of NaCl How many atoms is this 9 3x1024 3 7 x 1026 1 9x1026 8 2 x 1023 O O O O Previous

You mix 500 mL of 7 5 Travasol and 500 mL of 60 dextrose solution and 300 ml of sterile water for injection What are the percentage strengths of the Travasol and dextrose in the mixed solution

1 pts Volume of blood lost due to one hookworm ml hookworm 6pts Question 2 Prepare a hand drawn plot of the two variables using the grid sheet in the lab manual or other graph paper a Include a title axis labels with units and a trendline 1 pts b Estimate the total blood volume lost per day when 74 hookworms are present in the intestine Volume of blood lost mL 1pts c Estimate the number of hookworms that would drain 38 2 cm of blood per day Number of hookworms 0 50 4pts

1 The chemical formula for the ionic compound formed when elements of Ca and N react is when lithium and sulfide ion react is when iron II and chlorine react is aluminum and sulfate ion react is when

Tools Natural goldenrod pigment is a yellow dye that changes to a bright red color in the presence of a basic solution and remains yellow in contact with an acidic or neutral solution Peter is using goldenrod paper to test three solutions he prepared Cup 1 Solutions for Investigation Cup 2 Cup 3 Laundry detergent diluted in cup water Lemon juice Tap water He writes a secret message using an old piece of white wax candle 1 Science Goldenrod paper Tap Laundry Lemon detergent juice water Because Peter wants his message to be clearly visible in a red background at the end of his investigation in

Tools Radish extract indicator turns to a bright red color in low pH solutions and mustard yellow in solutions with a high pH value If a teacher places this radish extract indicator in a NaOH water solution which of the following accurately explains what will happen A B The indicator will not turn colors because there is an equal amount of Na and OH ions dissolved in water and the solution is neutral The indicator will turn bright red because there are more H than OH ions and the Answered Incorrectly

Directions Solve the following stoichiometry problems Show all equalities and con factors Place a box around your final answer Don t forget about Significant figures SHOW ALL YOUR WORK 4 points each 1 How many moles of gold Au 79 are in 57 80 grams of gold 2 How many liters of iodine gas 1 53 are in 4 00 x 10 moles of the gas at STP 3 How many molecules are there in 93 8 moles of NaCI 4 How many grams of KF are in 3 65 moles of KF 5 How many moles are in 37 5 L of chlorine gas CI 17 at STP

3 2 points Eons of wind and rain cause a mountain to crumble to dust Is this a chemical or physical change Chemical Physical Previous

1 Refer to the following equation 3Cu s 8HNO3 aq 3Cu NO3 2 s 2NO g 4H O 1 A 6 moles of Cu will produce moles of H O B Calculate the number of moles of water produced when 3 3 mol of Cu NO3 2 are formed in the reaction C How many grams of Cu would be needed to react with 2 0 mol HNO3 D If you could drop 12 atoms of copper into a beaker containing nitric acid how many molecules of NO would be produced E If you have 8 atoms of nitrogen on the reactant side of the equation then how many atoms of nitrogen will be on the product side of the equation F How many grams of NO would be made from 16 grams of Cu in the reaction

4 Volume in mL is required to dissolve 5 00 g CaCl to make a 2 50 M solution

Write a paragraph about the following Choose one of the following diseases and write about what the disease is how the nervous system is involved in the disease which part of the brain or spinal cord has been damaged and if there are any medications or medical advances to help that disease Diseases 1 Parkinson s Disease 2 3 4 5 Dementia or Alzheimer s Disease Meningitis Spinal Muscular Atrophy Brain Cancer

2 In a solution prepared by dissolving CaCl s in water what is the solute and what is the solvent

2 When ice melts this phase change is an endothermic exothermic process and AH is negative positive

3 List each as being a physical change or a chemical change butter melting butter burning sugar dissolving in water a sandwich getting digested

1 Answer the questions that follow by referencing the equation below showing the reaction of hydrogen sulfide with nitric acid 3 H S g 2 HNO aq 2 NO g 4H O 1 3S s a Determine the limiting reactant when 21 2 grams of nitric acid are allowed to react with 9 33 liters of hydrogen sulfide under STP conditions b Calculate the theoretical yield of water in grams based on the reaction in part a c Calculate the mass of excess reactant remaining from the reaction in part a d Calculate the percent yield of sulfur in the reaction in part a given that 10 8 grams of sulfur are isolated from the reaction

1 Which two products are produced when equal mole amounts of hydrochloric acid HCI and sodium hydroxide NaOH are combined NH4 OH identify the two proton 2 Given the equation NH3 H O donors and the two proton acceptors

Make sure to balance the equation no need to show work 1 4 7 2 Double replacement 3 2 HCI 3 2 2 Al 302 4 6 6 6 Directions Complete the following reactions that are happening in water Make sure to tell the states of matter for all compounds involved If the reaction is not possible state that 99 5 Synthesis aq 2 Na 1 Pb NO3 2 2 KOH aq aq 5 2 AI NO3 3 3 Zn 6 NaOH K S aq S LiC H3O2 aq a Na2S s b Ba NO3 2 s NH4Cl s Na2CO3 s aq occurring and predict their products 1 NaCl aq 2 CaCl2 2 K CO3 2 NaCl H S 8 Which net ionic equation is correct 2Na aq S2 aq Ba aq 2NO3 aq 2 NH4 aq Cl aq 2Na aq CO3 aq 2KCl CaCO 3 7 2 2AL0 2KNO Pb OH s aq Z NO No reaction because more Al is 2 KOH Na S aq Lick Caq NaC H O aq s reactive

Circumference cm 25 20 15 5 0 0 2 3 4 Diameter cm 5 y 3 0004x 0 3284 R 0 9968 6 7 8 1 pts a Visually estimate the diameter in centimeters of a circle with a circumference of 3 94 inches Diameter cm 1pts b Calculate the diameter in centimeters when circumference 3 94 inches using the equation of the line Use the graph to ensure that this value is reasonable

5 magnesium carbonate Mg CO3 molar mass of compound Ma

Which line of poetry demonstrates consonance O And all should cry Beware Beware His flashing eyes his floating hair O So might I standing on this pleasant lea I wandered lonely as a cloud When all at once I saw a crowd A host of golden daffodils O A poet could not but be gay In such a jocund company

A student is modeling an electric circuit containing three light bulbs and a battery Which model shows a circuit where the current flowing through each bulb will be the same as the current at point X A C X CD X D 5 B D X X

B When AgNO3 aq is mixed with NaCl aq which type of reaction will occur A single replacement synthesis decomposition double replacement B C D

Analyze This The ionic bond between magnesium Mg and fluorine F forms as a result of e transfer One element donates or gives away one or more e s The other element accepts or receives the e s To begin identify the e shell diagram for magnesium and for fluorine Mg Tap to Select an Electron Shell Diagram F Tap to Select an Electron Shell Diagram Student Name 14979 stu mps al Level Electron Transfe Progress Repor 1 2

Please use the following potential energy diagram to answer questions 4 and 5 Energy A B C Reaction Progression 4 Is this reaction exothermic or endothermic Activation Energy 5 Is activation energy required for the forward reaction the reverse reaction or