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Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

chemistry - 3.1.6
At a high temperature, the equilibrium constant for the decomposition of hydrogen iodide is 65.0. If the initial concentration of HI is 1.60 M, what is the concentration of hydrogen at equilibrium? 2Hl(g) H2(g) + I2(g) A. 1.42 M B. 0.753 M C. 0.240 M D. 0.802 M I'm actually ...

Chemistry
A 0.2512 stock sample of HCl is tirade to equivalence . If 16.77ml of 0.1410 M NaOH is required to reach the equivalence point, what volume of stock HCl was used for the tritation?

chemistry - 4.1.4
The [OH-] ion concentration of a sample is 1 × 10-10 M. What is the concentration of [H+] in the sample at 25°C? A. 1 × 10-14 M B. 1 × 10-4 M C. 1 × 10-10 M D. 1 × 10-6 M I think the answer is C. is this correct?

chemistry
The problem is as follows: The toxic metal cadmium Cd2+ has a tendency to complex with as many as 4 Cl- ions. The complexation reactions can be written as: Cd2+ + Cl- ---> CdCl+ log Kf,1 = 1.98 Cd2+ + 2Cl- ---> CdCl2^0 log Kf,2 =2.60 Cd2+ + 3Cl- ---> CdCl3- log Kf,3...

chemistry
What is a neutralization reaction? A. A reaction that involves neutral reactants B. A reaction in which the reactants are a salt and water C. A reaction in which the product is either acidic or basic D. A reaction that removes essentially all H+ and OH- I know that it isn't A ...

chemistry
If the equilibrium constant is much less than 1, what can you conclude about the concentrations of the reactants and products? A. Reactants are in the numerator of the equilibrium expression, so the concentration of the reactants is high. B. Products are in the numerator of ...

chemistry
How can you shift the equilibrium of the reaction between hydrogen and chlorine toward the products? H2(g) + Cl2(g) --> 2HCl(g) A. Add Cl2. B. Remove H2. C. Increase the pressure. D. Add HCl. would the answer to this one be to add Cl2? so answer A?

chemistry
Given the reaction: Cu2+(aq) + S2-(aq) CuS(s) What will happen (a) if CuSO4(aq) is added? And (b) if Na2SO4(aq) is added? A. (a) Nothing; (b) Less product will form B. (a) Less product will form; (b) Nothing C. (a) Nothing; (b) More product will form D. (a) More product will ...

chemistry
The equilibrium constant for the formation of phosphorus pentachloride is 1.9. If the partial pressure of each gas is 0.5 atm, will the reaction (as written) proceed forward or backward to reach equilibrium? PCl3(g) + Cl2(g) PCl5(g) A. Backward, because K is greater than Q B. ...

chemistry
What effect does raising the temperature of the reaction chamber at a constant pressure have on the following reaction at equilibrium? 2NO2(g) N2O4(g) + heat A. The equilibrium shifts toward the reactants because the reverse reaction is endothermic. B. The concentration of NO2...

Chemistry
covert Joules/Kevin to (atm)(nm^3)/(K) I have done this so far. J*[1L atm]/[101.33J]*[(.001m)^3]/[1L]*[10^9n]/​[1m] Thank you

Chemistry
When carbon is burned in air, it reacts with oxygen to form carbon dioxide. When 26.4 g of carbon were burned in the presence of 82.1 g of oxygen, 11.7 g of oxygen remained unreacted. What mass of carbon dioxide was produced? Express your answer to one decimal place and ...

chemistry
Why does the density of gas in a hot air balloon decrease as the gas is heated? A. The mass of gas decreases as temperature increases. B. The mass of gas increases as temperature increases. C. The volume of gas decreases as temperature increases. D. The volume of gas increases...

AP Chemistry
If the pH of a nitric acid solution is 2.34, then what is the molarity of nitric acid in the solution? A. 1.6 × 10-4 M B. 3.8 × 10-3 M C. 2.2 × 10-2 M D. 4.6 × 10-3 M

AP Chemistry
What should be the range for the exponent of [H+] in solutions that are characterized as acidic? A. 0 to -0.07 B. 0 to 0.7 C. 0 to -7 D. 0 to 7

ap chemistry
What is the [H3O+] of a solution with [OH-] = 6.3 × 10-4 M? A. 6.3 × 10-18 M B. 10.80 M C. 6.3 × 10-4 M D. 1.6 × 10-11 M DrBob222 can you help me with this question please?

chemistry
What is the chemical equation that describes the complete neutralization of H3PO4 by NaOH? A. H3PO4 + 2NaOH Na2HPO4 + 2H2O B. H3PO4 + H2O H2PO4- + H3O+ C. H3PO4 + NaOH NaH2PO4 + H2O D. H3PO4 + 3NaOH Na3PO4 + 3H2O

chemistry
Which of the following is true about the results of a neutralization reaction? A. An acid and a base form water and salt. B. Water reacts with a base to form the hydroxide ion. C. Water reacts with an acid to form the hydronium ion. D. An acid and a base dissociate into their ...

chemistry
Knowing what information would allow you to order gas molecules according to their velocity? A. Pressure and temperature B. Volume and molecular mass C. Pressure and volume D. Temperature and molecular mass

chemistry
How does table salt (NaCl) dissolve in water? A. Water molecules hydrogen bond with sodium ions and chloride ions. B. Each sodium ion is surrounded by chloride ions. C. Each NaCl molecule is surrounded by water molecules. D. The oxygen atoms in water molecules attract sodium ...

chemistry
When we are calculating the molality of KNO3 in H2O do we add i the van hoff factor

chemistry
At what Celsius temperature will the numerical reading on the Fahrenheit thermometer be 44 degress less than that on the Celsius thermometer?

Chemistry
How much energy is needed as heat at a pressure of 1 ATM when 78g of liquid ethanol (C2H5-OH) at 298 K is converted to solid enthalpy at 159 K (FP). The molar enthalpy fusion is -277.6 KJ/Mole, and heat capacity of liquid ethanol is 112.3 J/mole k.

chemistry
how many moles of NH3 does it take to make 8.0 mol of H20 according to the reaction shown below? 4NH3 + 5O2 --> 4NO + 6H2O I REALLY NEED HELP WITH THIS AS I AM LOST. PLEASE PROVIDE NOTES.

Chemistry
At constant pressure, which of these systems do work on the surroundings? A(s)+B(s)-->C(g) 2A(g)+2B(g)--> 3C(g) A(g)+B(g)-->3C(g) 2A(g)+3B(g)-->4C(g) I've tried everything and I just don't understand what I'm doing wrong.

Chemistry
Estimate the orders and rate constant K from the results observed for the Reaction. What is the rate when [H2O2]=[I-]=[H+]=1.0M? H2O2 + 3I- + 2H+ →I3- + 2H2O Experiment H2O2 [I-] [H+] Initial rate MS-1 1 0.010 0.010 0.0050 1.15e-6 2 0.020 0.010 0.0050 2.30e-6 3 0.010 0....

Chemistry
When ice melts, it absorbs 0.33 kJ per gram. How much ice is required to cool a 13.0 oz drink from 71 ∘F to 39 ∘F, if the heat capacity of the drink is 4.18 J/g∘C? (Assume that the heat transfer is 100 % efficient.)

Chemistry
Which of the following will contain more atoms: 12g of carbon or 12g of magnesium? Give a reason for your answer. Thanks

chemistry
Arrange given metal in decreasing order of electrical conductivity ( Al ,Ag ,Hg ,K,Ca

Chemistry
A chemist wants to make 500.0 mL of 0.215M NaCl. What mass of NaCl is needed? would it be .500 L x .215 M = .1075 mol NaCl .1075 mol x 58.44g NaCl = 6.28g NaCl needed

Chemistry
What volume of 12.1M HCl(aq) is required to make 435 mL of 0.100M HCl? would i just follow the equation V1xM1=V2M2 V1x12.1=.435Lx.100M = 0.00360 L

chemistry
Silver chloride (AgCl) is a white solid. For the equilibrium reaction AgCl(s) = Ag+(aq) + Cl‐(aq) The Ksp for AgCl = 1.6 * 10‐10. At equilibrium, would you expect to have more silver and chloride ions or more solid silver chloride?

biological chemistry
How many calories of heat are needed to increase the temperature of 55 g of ethanol from 18 Celsius to 48 Celsius

chemistry 102
what will happen if copper is overheated during the drying process? How will this affect the percent recovery?

chemistry
In an electrolytic solution the density of CuSO4 decreases or increases or remains constant?

chemistry
Which is most acidic in its aqueous solution? a)FeCl3 b)AlCl3 c)NiCl3 d)BeCl2

chemistry
on heating 25g of a saturated solution to dryness at 60c,4g of anhydrous salt was recovered.calculate it's solubility in grammes per 100g of solvent

chemistry
When are more products of a reaction available initially than at equilibrium? A. K = 0 B. Q < K C. Q = K D. Q > K

chemistry
Given the following solubility constants, which list arranges the solutes in order of increasing solubility? CaCO3: Ksp = 2.8 × 10-9 Ca(OH)2: Ksp = 5.5 × 10-6 CaSO4: Ksp = 9.1 × 10-6 CaF2: Ksp = 5.3 × 10-9 A. CaSO4 < Ca(OH)2 < CaCO3 < CaF2 B. CaSO4 < Ca(OH)2 &...

chemistry
Given the equilibrium concentrations in the table, what is the equilibrium constant for the synthesis of ammonia at this temperature? 3H2(g) + N2 2NH3(g) A. 0.0035 B. 0.014 C. 0.066 D. 0.017

chemistry
What change do you expect if the value of the reaction quotient is greater than the value of the equilibrium constant? A. The rate of the forward reaction is greater than the rate of the reverse reaction. More reactant forms. B. The rate of the forward reaction is greater than...

chemistry
Which of the following is true about the results of a neutralization reaction? A. An acid and a base form water and salt. B. Water reacts with a base to form the hydroxide ion. C. Water reacts with an acid to form the hydronium ion. D. An acid and a base dissociate into their ...

chemistry
What does a buffer do? A. It resists a change in pH when H+ or OH- is added to a solution. B. It prevents an acid-base reaction from happening. C. It prevents an acid or base from being neutralized. D. It prevents a salt from forming in solution.

chemistry
Why is HCl required in the stomach? A. To transport proteins into the small intestines B. To help absorb other acids in the stomach C. To catalyze the digestion of carbohydrates D. To aid in the digestion of proteins

chemistry
The [OH-] ion concentration of a sample is 1 × 10-10 M. What is the concentration of [H+] in the sample at 25°C? A. 1 × 10-14 M B. 1 × 10-4 M C. 1 × 10-10 M D. 1 × 10-6 M

chemistry
Which of the following chemical reactions represents a neutralization reaction? A. CH4 + 2O2 CO2 + H2O B. HCl + NaOH H2O + NaCl C. NH3 + H2O NH4++ OH- D. CH3COOH + H2O CH3COO- + H3O+

Chemistry
When 1.5 grams of salt are added to 12.0 grams of water and the salt dissolves, what is the mass of the system?

Chemistry
Sodium + Sulfuric Acid and Phosphoric Acid + Magnesium Hydroxide a.write the formula b. supply the product c.type of reaction d. balancing

chemistry
Okay so i have this titration question and I don't really know the steps because everyone explains it differently. IF someone could explain me the steps of how i could solve this questions and other like this. Thanks In three runs of titration 22.8mL, 221.mL, 22.2mL of 0.200 ...

Chemistry
home / study / science / chemistry / questions and answers / a subtilisin with an active site mutation of his ... Question: A subtilisin with an active site mutation of His t... EDIT QUESTION A subtilisin with an active site mutation of His to Ala had a substantially decreased...

Chemistry
A rectangular solid of unknown density is 6cm long, 3cm high, and 7cm wide. The mass of this solid is 250g. Calculate the density.

Chemistry
An enzyme has velocities of 0.11 nmol/min at a substrate concentration of 1 μM, 0.34 nmol/min at a substrate concentration of 5 μM, and 0.45 nmol/min at a substrate concentration of 10 μM. What is the Vmax for the enzyme if the KM is 5 × 10–6 M? A. 0.22 nmol/...

chemistry
At 1 atm, how much energy is required to heat 51.0 g of H2O(s) at –16.0 °C to H2O(g) at 125.0 °C?

chemistry
Which of the following is true about the results of a neutralization reaction? A. An acid and a base form water and salt. B. Water reacts with a base to form the hydroxide ion. C. Water reacts with an acid to form the hydronium ion. D. An acid and a base dissociate into their ...

chemistry
What is the general form for the simplest type of acid-base reaction? A. acid + base salt + water B. acid + base base + acid C. acid + base H+ + OH- D. acid + base solid + water

chemistry
A, B, C, and D are 4 salts whose Ksp values are 9.21 × 10-8, 7.44 × 10-11, 1.07 × 10-21, and 38.65, respectively. What is the correct arrangement of their solubilities in decreasing order? A. D, A, B, C B. C, B, A, D C. A, B, D, C D. C, B, D, A

chemistry
Acetic acid is known to be a weak acid. What will happen to the acidity of the solution when sodium acetate is added to acetic acid? A. The solution will become more acidic. B. The pH will remain the same. C. The solution will become less acidic. D. The solution will become ...

chemistry
Which of the following bases could you write an equilibrium expression for? A. Ba(OH)2 B. KOH C. NaOH D. NH3

chemistry
During a chemical reaction, if Q = K, what can be said about the reaction? A. The reaction still proceeds in both directions, but the net result is that the reactant and product concentrations do not change. B. The amount of product is always equal to the amount of reactant. C...

chemistry
Which of the following is true of the solubility product constant? A. It is the product of the initial concentrations of the ions in a solution. B. It is an equilibrium constant. C. It is an equilibrium position. D. Its value changes in the presence of a common ion. Hi, I know...

chemistry
Which equation would describe the following equilibrium constant? Kc = [Bi3+]2[S2-]3 A. Bi2S3(s) + 6HCl(aq) 2BiCl3(aq) + 3H2S(aq) B. Bi2S3(s) 3Bi2+(aq) + 2S3-(aq) C. BiS(s) Bi3+(aq) + S2-(aq) D. Bi2S3(s) 2Bi3+(aq) + 3S2-(aq)

chemistry
What happens to the following reaction at equilibrium if the pressure is decreased? 2H2(g) + O2(g) 2H2O(g) A. The equilibrium shifts left because Q < K. B. The equilibrium shifts right because Q < K. C. The equilibrium shifts right because Q > K. D. The equilibrium ...

chemistry
What is the equilibrium expression for the change when iron(II) chloride dissolves? FeCl2(s) Fe2+(aq) + 2Cl-(aq)

Chemistry
When a 0.326 g sample of FeCl2·xH2O is heated to remove all water, a mass of 0.254 g remains. Determine the value of x.

Chemistry
After you preform your experiment, you determine that the Kf value for naphthalene is 6.89 °C/m . You are using 10g of naphthalene and added 1.0 g of your unknown. The the freezing point of the solvent decreased by 4.42 °C when the unknown was added. Knowing this information...

Chemistry
How much ethylene glycol (C2H6O2, the major component of antifreeze) must be added to 1 L of water to keep it from freezing at -17 oC? Kf = 1.86 oC/m. I got 163.96 or 164 for my answer but that isn't correct and I don't know what I'm doing wrong.

chemistry
calculate number of ions of chloride in 444g of calcium chloride

chemistry
Acetylene (C2H2) burns with oxygen it gives CO2 and H2O. Write down it's Skelten equation?

Chemistry
Calculate the mass and moles of iodine that reacted in the formation of 2.7132 grams of ZnI2. im slighty confused about the use of iodine, would it be diatomic in the equation for example would i use the conversion 1 mol ZnI2 = 1 mol I2 or 1 mol ZnI2 = 2 mol I

Chemistry
How many milliliters of a 0.48 M HCl solution are needed to react completely with 7.4 g of zinc to form zinc(II) chloride? Answer in units of mL.

Physical Chemistry
5. Assume you have a 45°C 100g block of gold (cp=0.129J/g°C) and a 150°C , 150g block of silver (cp=0.240J/g°C)(1). You place these blocks into an adiabatic container in thermal contact. a. Calculate the final temperature b. Calculate the heat transferred c. Describe how ...

chemistry
Which of the following is an ortho directing group? a) CN b) CO2Me c) OMe d) NO2 I have drawn most of them out, CN has no delocalised electrons to contribute e- density hence EWG. For NO2 inductive effect is strong and hence is a EWG and meta directing. OME EDG -> Ortho im ...

Chemistry
Your lab partner tells you that he has prepared a solution that contains 1.5 moles of NaOH in 1.5 L of aqueous solution, and therefore that the concentration of NaOH is 1.5 M. (a) Is he correct (b) If not what is the correct concentration

Chemistry (equilibrium)
C2H6(g) <=> C2H2(g) + 2 H2(g) The ΔH° for the reaction above is +312 kJ. The system is initially at equilibrium. In which direction will the reaction shift in each of the following situations? e) The temperature is decreased. g) He is added at constant volume. h) ...

science ap chemistry
What is the equilibrium expression for the following acid dissociation reaction? CH3COOH + H2O CH3COO- + H3O+ A. [CH3COO-][H3O+]/[CH3COOH][H3O] B. [CH3COOH][H2O]/[CH3COO-][H3O+] C. [CH3COOH]/[CH3COO-][H3O-] D. [CH3COO-][H3O+]/[CH3COOH]

chemistry help
Which of the following is true of the solubility product constant? A. It is the product of the initial concentrations of the ions in a solution. B. It is an equilibrium constant. C. It is an equilibrium position. D. Its value changes in the presence of a common ion.

chemistry help
During a chemical reaction, if Q = K, what can be said about the reaction? A. The reaction still proceeds in both directions, but the net result is that the reactant and product concentrations do not change. B. The amount of product is always equal to the amount of reactant. C...

chemistry help
How does too little acid cause gastric distress? A. More than enough acid is present to digest proteins, resulting in inadequate digestion of proteins. B. The pH of the stomach becomes so high that proteins are not digested properly. C. The pH of the stomach becomes so low ...

chemistry
Which of the following statements is true of a solution at pH 7? A. Kw and Kb are equal. B. Kw and Ka are equal. C. Kw, Ka and Kb are equal. D. Ka and Kb are equal.

Chemistry
What is the name of the compound NO3. (Not NO3-, nitrate)???? Please help!

chemistry
Which of the following is true about the results of a neutralization reaction? A. An acid and a base form water and salt. B. Water reacts with a base to form the hydroxide ion. C. Water reacts with an acid to form the hydronium ion. D. An acid and a base dissociate into their ...

chemistry
A precipitate of copper(II) hydroxide is formed in a reaction. What change will help to dissolve the copper(II) hydroxide? Cu^2+(aq) + 2OH^-(aq) Cu(OH)"subtext"2(s) A. Adding NaOH B. Adding HCl C. Removing CuCl2 D. Removing H2O is the answer for this d? removing H2O??

chemistry
Which of the following is true of the solubility product constant? A. It is the product of the initial concentrations of the ions in a solution. B. It is an equilibrium constant. C. It is an equilibrium position. D. Its value changes in the presence of a common ion.

chemistry
What happens to the following reaction at equilibrium if the pressure is decreased? 2H"subtext"2(g) + O"subtext"2(g) 2H"subtext"2O(g)

chemistry
Which statement describes a chemical reaction at equilibrium? A. The forward reaction happens slightly faster than the reverse reaction. B. The reaction has stopped because all reactants have been used up. C. The forward reaction happens at the same rate as the reverse ...

chemistry
A 1.272 g sample of a mix Na2CO3 and NaHCO3 vol of 0.24 N HCl required for PP end point 26.92 ml after the addition 52.21 ml more of the HCl and boilling out CO2 the vol of 0.12 NaoH required to give a pink colour to the soln = 4 ml

math or chemistry
5.4 x10^-2 by 2.5 x10^-3 by 7.9 x10^-3m volume = 106.65 x10-8m^3 Check pls yesterday you said 106.65 x10^-6. If you add 2+3+3 you get 8 is that right? Just want to make sure I'm doing it right. Thank you. I may have witten it differently.

chemistry
Vinegar is a solution of acetic acid, a weak acid. How can you produce more acetate ions in the solution? CH 'subtext' 3 COOH(aq) H+(aq) + CH 'subtext' 3 COO^- (aq) A. Evaporate some of the water. B. Decrease the pressure. C. Increase the volume of the container. D. Add more ...

Chemistry
How does hybridisation of PCL5 change when it is decomposed to PCL3 and Cl2?

chemistry
Sig figs 33.067. 5 sig figs .0908. 3sig figs 1099. 4 .0087. 2 check pls

math or chemistry
Check pls. 5.4 x 10^-2 by 2.5 x 10^-3 by 7.9 x10^-3 m volume = 107.44 x 10^-8 m^3

chemistry
05 mL of sample water needs10.9 mL .01M EDTA solution. what is the accurate Hardness of sample in CaCO3 (mg/L)? pls expalin.

Chemistry
For my lab, I have been asked to calculate the pKa of an unknown amino acid. We titrated the unknown amino acid with NaOH. The pKa needs to be calculated using the Henderson Hasselbach Equation. Obviously you can just get the pH from any point on the graph but what values do ...

Chemistry urgent please
How much mL of dilute nitric acid is needed to add in control solution in chloride limit test in sodium hydroxide sample???can u please give me Answer urgently??

Chemistry
The density of an unknown gas is 1.23 g/L in 330K and temperature 25.5 pressure kPa. What is the molar mass of the substance?

Chemistry
Ammonia is composed of hydrogen and nitrogen in a ratio of 9.33 g of nitrogen and 2.00 g of hydrogen. if a sample of ammonia contains 6.28 g of hydrogen, how many grams of nitrogen does it contain?

chemistry
Which of the following reactions have a positive delta S rxn? check all that apply 1) A(s)+2B(g) -->C(g) 2) 2A(g)+3B(g) -->4C(g) 3) 2A(g)+2B(g) -->5C(g) 4) 2A(g)+B(s) -->3C(g) Not sure how to tell if the reaction is positive.

Chemistry
Calculate the degree of dissociation and oh conc in 0.1m (nh4)3po4 having alpha 50%

Chemistry(please check my answer)
The transuranium elements A. are the elements with atomic numbers above 92. *** B. occur in nature. C. are sometimes radioactive. D. all of the above

chemistry
If 100 g of butane are reacted with unlimited amounts of oxygen, how much carbon dioxide (in grams) and how much water (in grams) should form?

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