# Calculate the pH of a 0.21 M CoCl3 solution. The Ka value for Co(H2O)63+ is 1.0 10-5.

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### Chemistry

0.717 g of a compound containing carbon, hydrogen, and oxygen is burned and found to produce 1.02 g CO2 and 0.624 g H2O. The molar mass of the compound is 124 g/mol. (a) Write a chemical equation for the combustion of this unknown hydrocarbon. (b) Determine the # of g and ...

### Algebra Math 116

How can you tell if a value is a solution to an inequality.

### math

solve the absolute value equation |3a+8|=|4a-4| the solution set is

### maths

give the solution of the initial-value problem dx/dy=(1+2cos^2(x))/y, (y > 0), y= 1 when x = 0. Thanks.

### maths

give the solution of the initial-value problem dy/dx=(1+2cos^2(x))/y, (y > 0), y= 1 when x = 0. Thanks.

### trigonometry

is the value 3pi/2 is a solution for the equation 2sin^2x-sinx-1=0

### calculus

find the solution of the initial value problem y'=xye^x; y(1)=1

### ALGEBRA 2

For what value of k does the system below not have a unique solution? -1x + 7y + 2z = 6 2x + 1y + kz = -11 3x - 6y - 2z = -25 A.5 B.0 C.-2 D.-8

### Algebra

Which value of x is the solution of the equation 1/7 + 2x/3 = (15x-3)/(21) ? (Those are fractions) (1) 6 (2) 0 (3) 4/13 (4) 6/29

### Chemistry

ph of a 0.234 m nahco3 solution look up the appropriate ka or kb value

### MATH

If (-2,y) is a solution to the equation 2x-3y=5, what is the value of y? I'm having trouble with this one

### math

Determine whether each value of x is a solution of the equation 7-3x=5x-17 a. x- -3 b. x-0 c. x-8 d. x-3 Helppp!!!!!

### Math

2.which value is a solution of the equation 3-2x=-5? a.2 b.4*** c.-2 d.1/5 NEED ANSWER ASAP

I really need help on this problem... ===================== Hydrocarbon Formula Delta H (kj/mol) 1,3-Butadiene C4H6(g) 111.9 a) calculate the fuel value in kJ/g for this compound and determine the percentage of hydrogen by mass. I've tried it for hours yet I can't figure out ...

### Chemistry

Each of the following mixtures is placed in a dialyzing bag and immersed in distilled water. Circle the substances that will be found outside the bag in the distilled water. a. KCl solution and glucose solution b. albumin solution (colloid) c. albumin solution (colloid), KCl, ...

### Chemistry

Silver chloride has Ksp=1.6x10^-10 and silver cheomate has Ksp=9.0x10^-12. We have 1.00 liter of a solution contains both nacl(0.10M) and Na2cro4(0.10M) solid AgNo3 is added slowly and the solution is stirred well. a) which precipitate first Agcl or AgCro4? B)what are the ...

### Chemistry

describe the preparation of 12 mL of a 0.050 M solution of each of the halogens, using the reactions in the preceding question. Available to you are solid Ca(OCl)2; 0.20 M solutions of NaCl, NaBr, NaBrO3, and CuSO4; a 0.40 M solution of NaI; a 0.50 M solution of H2SO4; ...

### chemistry

Two aqueous solutions of sucrose, C12H22O12, are mixed. One solution is 0.1495 M sucrose and has d = 1.018 g/mL; the other is 12.00 % sucrose by mass and has d = 1.038 g/ml. Calculate the moles C12H22O12 percent in the mixed solution. Please provide steps 100 mL for each soln.

### chemistry

Consider the dissolution of CaCl2. CaCl2(s) Ca2+(aq) + 2 Cl-(aq) ΔH = -81.5 kJ A 13.0 g sample of CaCl2 is dissolved in 134 g of water, with both substances at 25.0°C. Calculate the final temperature of the solution assuming no heat lost to the surroundings and assuming ...

### Chemistry

Why can't we apply Kd directly to a equilibrium solution of CCl4 and H2O,with CH3COOH dissolved? Do CH3COOH form polymers in CCl4? or are their single molecules of CH3COOH in CCl4?

### Chemistry

What should be the pH value of the solution to double the solubility of the ionic compound NX? Ka of HX=2*(10)^-5 M My thoughts on the question: Let the solubility of NX=x M 1) NX(s)<====> N+(aq) + X-(aq) eq:con: x x (moldm-3) X^-<===> HX + OH^- -->(2) HX<...

### college chemistry

.361 g of a non-volatile solute is dissolved in 160.0 g of water. The solute does not react with water nor dissociate in solution. Assume that the resulting solution displays ideal Raoult's law behaviour. At 90 oC the vapour pressure of the solution is 5.1701×102 torr. (The ...

### Chemistry

When 6200g of ethylene glycol and 16600g terephtalic acid reacted completely to generate poly(ethyleneterephtalate)(PET),how many grams of H20 generated? My working: mol of ethylene glycol = 6200g/(62g/mol) = 100 moles mol terephtalic acid = 16600g/(166g/mol) = 100 moles So,...

### Idontgetit

The value of the equilibrium constant (Kp) as represented by the first chemical equation is 2.00 x 10-2 at 730 K. Calculate the value of the equilibrium constant (Kp) for the second equation at the same temperature. Express answer in scientific notation. 2HI(g) = H2(g)+I2(g) ...

### Chemistry

The aquation of tris(1, 10-phenanthroline)iron(II) in acid solution takes place according to the equation: Fe(phen)3^2+ + 3H3O + 3H2O==> (Fe(H2O)6^2+ + 3 phenH^+ If the activation energy is 126 kJ/mol and frequency factor is 8.62 x 1017 s-1, at what temperature is the rate ...

### Chemistry

A solution is prepared by dissolving of pure HC2H3O2 and of NaC2H3O2 in of solution (the final volume). (a) What is the pH of the solution? (b) What would the pH of the solution be if of 0.250 M NaOH were added? (c) What would the pH be if of 0.40 M HCl were added to the ...

### chem

Determine whether the following are endothermic or exothermic. 2H2O2 (l) ¨ 2H2O(l) + O2(g) ∆H = -190 kj C(s) + H2O (g) ¨ CO (g) + H2 (g) ∆H = +113 kj C4H9OH(l) + 6 O2(g) ¨ 4 CO2(g) + 5 H 2O(g) ∆H = -2456.1 2 C(s) + H2(g) ¨ C2H2(g) ∆H = +226....

### chemistry

I have the answers, I am just interested in the formulas so that I can solve the problems, thanks! 1. Find the boiling point of a solution composed of 110g of HgCl2 (a non-ionizing solute) in 175g of water. 2. Find the freezing point of a solution composed of 50g IBr in 120 g ...

Calculate the PRESENT VALUE of the following ORDINARY ANNUITIES. Round to the nearest cent when necessary. Annuity Payment:(\$3,000) Payment Frequency: (Every Year) Time Period YRS:(15)Nominal Rate%:(10)Interest Compounded:(Annually)Present Value Of The Annuity is What?

### Chemistry

I need to calculate the valueof Kc for 5 test tubes for an experiment that I completed on determination of Kc. The equation used was Fe^3+ + SCN^-= FeSCN^2+ After creating an ice table for the first test tube my values for Fe and SCN were 6.5e-4M and for FeSCN I got 5.7e-5M. ...

### Chemistry

The experimentally determined rate law for the reaction H2 + NO --> ½N2 + H2O is Rate = k[H2][NO]2. Is the mechanism below possible? Step 1: H2 + NO --> N + H2O Slow Step 2: N + NO -->N2 + O Fast Step 3: O + H2 --> H2O Fast 1. Yes, because the slow step ...

### chemistry

1) MgO (s) + 2H (aq) -> Mg+2 (aq) + H2O (l) 2) Mg+2 (aq) + H2 (g)-> Mg(s) + 2H+ (l) 3) equation 1+ equation 2 = MgO (s) + H2 (g) -> Mg (s) + H2O (l) is it correct? if so, i need to write an expression which could be used to obtain the heat of formation of magnesium ...

### Chem Electron Config

A 10.0-g sample of C2H5OH is burned completely in air. How many molecules of H2O are formed? 3.92×1023 *How many grams are formed?* did anyone figure out how to get the grams of H2O formed?

### Chemistry

Suppose NaOH is added to the following system when it is at equilibrium. NH3 (aq) + H2O (l) = NH4 (aq) + OH (aq) a) in which direction will the reaction shift after the NaOH is added? b) will this stress increase or decrease the value of the reaction quotient, Q?

### chemistry

For each of the following acid-base reactions, calculate how many grams of each acid are necessary to completely react with and neutralize 2.1g of the base. 1) HCl(aq)+NaOH(aq)-->H2O(l)+NaCl(aq) 2) 2HNO3(aq)+Ca(OH)2(aq)-->2H20(l)+Ca(NO3)2(aq) 3) H2SO4(aq)+2KOH(aq)-->...

### Chemistry

Calculate delta H for the reaction below using Hess's Law: C2H6 ---> C2H2 + 2H2 ------------------------------------------ C2H2 + 5/2O2 --> 2CO2 + H2O (H = -1300 kJ) 2H2 + O2 --> 2H2O (H= -572 kJ) 2C2H6 + 7O2 --> 4CO2 + 6H2O (H= -3120 kJ)

### chemistry

A chemist must dilute 55.6 ml of 1.48 M aqueous silver nitrate (AgNO3) solution until the concentration falls to 1.00M. He'll do this by adding distilled water to the solution until it reaches a certain final volume. Calculate this final volume, in milliliters. Round your ...

### mathematics

hence calculate the value of x if the area is 25cm2

### math

Calculate the value of pie is 22 over 7,3,142

### math

16000000=10r-r^2. Calculate the maximum value of r.

### Maths

If 52n-24n=25n. Calculate the value of n.

### Physics

How many metric tons (1 metric ton = 10^3 kg) of H2O fell on a city? (1cm^3 of H2O has a mass of 1g = 10^-3 kg) Thus far I have: 10^-3 Kg x (1 metric ton/10^3) but I don't understand the significance of adding 1 cm^3 to the problem.

### Math

1. What is the value of z so that -9 and 9 are both solutions of x^2+z=103? a) -22 b) 3 c) 22 d) 184 2. What is the value of b in the triangle below? The triangle has one side that is 3b and another that is just b. The area of the triangle is 24in.^2. a) -4 in b) 4 in c) no ...

### Math

1. What is the value of z so that -9 and 9 are both solutions of x^2+z=103? a) -22 b) 3 c) 22 d) 184 2. What is the value of b in the triangle below? The triangle has one side that is 3b and another that is just b. The area of the triangle is 24in.^2. a) -4 in b) 4 in c) no ...

### Chemistry

you have 505mL of a .125 M HCl solution and you want to dilute it to exactly .100. How much water should you add? I got (.125M)(505mL)=(.100M)(Vf)= 631.25. But on my answer sheet they got 126 mL of H2O???? I don't know how she got it.

I have these 5 chemical equations and I keep getting the same 1:1 ratio on all of them. I must be doing something wrong! KCL + NaNO3 = KNO3 + NaCl HNO3 + KOH = H2O + KNO3 H2O + SO3 = H2SO4 4Na + O2 = 2Na2O 2NO2 = 2NO + O2

### chemistry

Suppose a substance has been prepared that is composed of carbon, hydrogen, and nitrogen. When 0.1156 gram of this compound is reacted with oxygen, 0.1638 gram of carbon dioxide (CO2) and 0.1676 gram of water (H2O) are collected. Assuming that all the carbon in the compound is...

### Chemistry

Weight of the Rock Salt Sample: .343 (g) Weight of the Rock Salt Solution: 9.910 (g) Trial #1 Trial #2 Trial #3 Weight of Rock Salt Solution Delivered (g) : .89 1.17 .786 Weight of AgNO3 Solution Delivered (g) : 1.53 .548 .786 Concentration of AgNO3 : 4.70e-4 (moles of AgNO3/g...

### chem

λ for one line of the hydrogen spectrum is .4118 x 10-4 cm. Use this value in the Rydberg equation to calculate the RH value using n1 = 2, and n2 = 5. I am not certain of your difficulty here. Can you amplify? How did you make the symbol for lamda? (1/lambda) = R(1/n1^2...

### AP Chem (Thank you for help)

Hey guys! Stuck on some Redox Reactions. I tried my best to put as much work as I could, but I'm super stuck on these ones. Thanks for any help: 1) Balance the equation as written, what is the coefficient for O2? NH4+ + O2-->NO2− + H2O (in basic solution) Maybe answer...

### chemistry

Hydrogen peroxide decomposes according to the following thermochemical reaction H2O2 --> H2O +1/2 O2 ; H= -98.2 kJ calculate the change in enthalpy when 1.00 g of hydrogen peroxide decomposes.

### physics 30

Given the reaction 3 NO2(g) + H2O(l) ¨ 2 HNO3(l) + NO(g) ƒ¢rH = -72.0 kJ, calculate the molar enthalpy of reaction, rH for: 1) NO2(g) 2) H20 (l) 3) HNO3 (l) 4) NO (g) Express you answer in Kj/mol

### Chem

Water was decomposed by the following reactions. Calculate the mass of HCl produced from 50.0 mL water assuming the following yields H2O=H2+O2 90% H2+Cl2=HCl

### college chemistry

Calculate the pH of the cathode compartment for the following reaction given Ecell = 3.01 V when [Cr3+] = 0.15 M, [Al3+] = 0.30 M, and [Cr2O72-] = 0.55 M. 2 Al(s) + Cr2O72-(aq) + 14 H+(aq) → 2 Al3+(aq) + 2 Cr3+(aq) + 7 H2O(l)

### i need help finding PH

Calculate the pH of the cathode compartment for the following reaction given Ecell = 3.01 V when [Cr3+] = 0.15 M, [Al3+] = 0.30 M, and [Cr2O72-] = 0.55 M. 2 Al(s) + Cr2O72-(aq) + 14 H+(aq) → 2 Al3+(aq) + 2 Cr3+(aq) + 7 H2O(l)

### chem

Calculate the number of grams of magnesium nitride necessary to produce 2.02 L of ammonia gas at STP. I got 4.55g for the upper question which is correct but idk how to do the bottom one: How many moles of magnesium hydroxide can also be formed? Mg3N2(s) + 6 H2O(l)--> 3 Mg(...

### Chemistry

A 32.907-g sample of a hydrate of Au (CN)3 contains 5.406 g H2O What is the formula for the hydrate? What is the percent water in this compound? What mass of this hydrate contains 100.0 g H2O?

### chemistry

how to prepare CO from this equation in the lab CaCo3 + 2HCl → CaCl2+H2O+ CO2 (g) Or CaCo3 ----(Heat 500 to 600 C0→ Cao +Co2 (g) 2- CO2 + H2 → CO (s) + H2O(g)

if i had a beaker with .0001M of Cu solution and copper solid (anode) and another beaker with 1M Cu solution and Cu solid (cathode), how would i calculate the half reactions of these two? would the two equations be: cu2+(aq) --> Cu(s) + 2e- and ?

### chemistry

At 29.6 degrees C, pure water has a vapor pressure of 31.1 torr. A solution is prepared by adding 86.7 g of "L" a nonvolatile nonelectrolyte to 390.0 g of water. The vapor pressure of the resulting solution is 27.6 torr. Calculate the molar mass of "L"

### CHEMISTRY

A solution household bleach contains 5.25% NaClO, by mass. Assuming that the density of bleach is the same as water(1.0g/ml). Calculate the volume of household bleach that should be diluted with water to make 500.0 ml of a ph= 10.26 solution. So, the first thing i do was to ...

### Chemistry

Using a table of standard electrode potentials (such as the one in your textbook), calculate the standard cell potential for a cell made by placing a zinc electrode in a Zn2+(aq) solution which is connected by an electrolyte to a Ag+(aq) solution containing a silver electrode...

### Chemistry

1) Using a table of standard electrode potentials (such as the one in your textbook), calculate the standard cell potential for a cell made by placing a zinc electrode in a Zn2+(aq) solution which is connected by an electrolyte to a Ag+(aq) solution containing a silver ...

### Chemistry

A 0.1873 g sample of a pure, solid acid, H2X was dissolved in water and titrated with 0.1052 M NaOH solution. The balanced equation for the neutralization reaction occurring is H2X(aq) + 2NaOH(aq) ¨ Na2X(aq) + 2H2O(l) If the molar mass of H2X is 85.00 g/mol, calculate the ...

### Chemistry partial molar volumes

The partial molar volumes of the CCl4 and benzene are 122cm3/mol and 98.0 cm3/mol, respectively in a solution in which mole fraction of chloroform is 0.2. Calculate the volume occupied by 2.5 moles of the solution. Thank yOu.

### Chemistry

A buffer is prepared by mixing 0.30 mole of formic acid (HCNO2) and 0.20 mole of sodium formate (NaCHO2) in enough water to make 0.50 liter of solution. Ka of formic acid is 1.7 x 10-4. Calculate the pH of the resulting buffer solution.

### chemsitry

100ml of h2s04 solution having molarity 1M and density 1.5g/ml is mixed with 400ml of water. calculate final molarity of h2s04 solution, if final density is 1.25g/ml. Answer 0.227M Who helps me to solve it Thank you a lot

### chemistry

Now use the average value of Kb the base dissociation constant of acetate anion to calculate an average value for Ka, the acid dissociation constant of acetic acid. Kb: 1.33x10^-10

### science

I am doing a titration lab and need help with a problem. (i used .100M H2SO4)(I used 10.0 ml of Ba(OH)2 solution and added 50.0 ml of distilled water making 60.0 ml total.) 1. Use the titration results to calculate the moles of H2SO4 that were used to reach the equivalence ...

### AP Chemistry

Calculate the concentration of Hg2+ ions in a saturated solution of HgS(s). (Ksp=1.7×10^52) Answer in units of mol/L What volume of solution contains one Hg2+ ion? Answer in units of L/ion

### Chemistry

100ml of h2s04 solution having molarity 1M and density 1.5g/ml is mixed with 400ml of water. Calculate final molarity of h2s04 solution if final density 1.25g/ml. Ans is 0.227M Who help me thanks a lot

### Chem

2 H2O (l) → 2 H2 (g) + O2 (g) Using the thermodynamic values to calculate accurate values of ΔHr and ΔSr, will the reaction be product favored at high temperature? Why? r stands for reaction

### AB Chemistry4

4 HCl + MnO2 ==> MnCl2 + 2 H2O + Cl2 How many grams of MnCl2 are formed when 36.0 grams of water are also formed? DO we have to calculate mole mass first?

### Chemistry

the equilibrium constant Kc for the reaction H2 + Co2 to H2O + CO is 4.2 t 1650°C initially .80 mol of H2 and 0.8 mol Co2 are injected into a 5.0 flask. Calculate the concentration of each species at equilibrium

### is the ph= o for the H+

Calculate the pH of the cathode compartment for the following reaction given Ecell = 3.01 V when [Cr3+] = 0.15 M, [Al3+] = 0.30 M, and [Cr2O72-] = 0.55 M. 2 Al(s) + Cr2O72-(aq) + 14 H+(aq) → 2 Al3+(aq) + 2 Cr3+(aq) + 7 H2O(l)

### chemistry

Calculate the number of moles of H2O2 required to produce 0.08 moles of HNO3 by the following reaction. 7 H2O2 + N2H4 2 HNO3 + 8 H2O

### Accounting

1. Complete Problem 14.1 on page 279 of the course text (solution is on page 501-502). Next, work the problem again using the following variables: project yield annual net cash inflows are \$10,500 for the next five years; interest rate of 16.5%, and the initial investment of \$...

### Chemistry HW!!!

1. If I dilute 75 mL of 0.50 M CaF2 solution to a final volume of 375 mL, what will be the molarity of the resulting solution? 2. What will be the final volume of the solution be if I start with a 250 mL of 1.38 M MgCl2 solution to make a solution with a concentration of 0.30 ...

### chemistry

Consider the exothermic reaction CoCl42-(aq) + 6 H2O(l) Co(H2O)62+(aq) + 4 Cl -(aq). Will the equilibrium concentration of CoCl42- increase or decrease when the following changes occur? a) HCl is added. (b) Co(NO3)2 is added. both of those compounds are not even in the ...

### Chemistry

Two isomers have the same formula but different structures: Co(H2O)5SCN, CO(H2O)5NCS. The 5's mean 5-H20's. Draw each of these structures and explain the difference between the two? I don't even know where to begin. I appreciate any kind of help at this point. Thanks!

### Chemistry

Use the info below to calculate how much it would cost you to produce 500g of NiSO4*6H2O . don't forget to include the cost of the original nickel token . Na2CO3*H2O costs \$6.58/3 kg 6 M H2SO4 costs \$12.65/5L 9 M HNO3 costs \$10.53/2.5L Show clearly how you obtained your answer...

### Accounting

I need some help with this question… It is confusing me… I have parts of it done but would like someone to help explain it to me. A truck was purchased on January 2 at a cost of \$60,000. It’s expected to be used for five years and to have a residual value of \$5,000 after...

### pre-calculus 11

I am asked to solve the absolute value equation of |1/2x +1| =x+1 graphically. I can solve this algebraically and consider two cases for the absolute value one being positive and the other negative. I know this will be a straight line and when I solved it algebraically x=0 the...

### pre-calculus 11

I am asked to solve the absolute value equation of |1/2x +1| =x+1 graphically. I can solve this algebraically and consider two cases for the absolute value one being positive and the other negative. I know this will be a straight line and when I solved it algebraically x=0 the...

### Physics

The active element of a certain laser is an ordinary glass rod 19.5 cm long and 1.04 cm in diameter. If the temperature of the rod increases by 77.3°C, calculate its increase in length.Calculate its increase in volume. Calculate its increase in diameter. (Use 9.0×10-6 °C-1 ...

### chemistry

5.0 mL of H2SO4 solution was titrated with 0.20 M NaOH standard solution. The volume of NaOH needed to reach the equivalent point was 9.5 mL. 1. In this titration setup, what is the titrant? and what is the analyte? 2. What is the number of mole of H2SO4 in the 5.0 mL solution...

### chemistry

A solution was made by dissolving 62.07 grams of a compound in 500.0 g of water. The compound was not ionic. The freezing point of the solution was measured and found to be – 1.86oC. Using the Kf value in your textbook , the molar mass of this compound can be calculated to ...

### chemistry

Glycerin (C3H8O3) is a nonvolatile liquid. What is the vapor pressure of a solution made by adding 180. g of glycerin to 321 mL of H2O at 39.8°C? The vapor pressure of pure water at 39.8°C is 54.74 torr and its density is 0.992 g/cm3.

### chemistry

Glycerin, C3H8O3, is a nonvolatile liquid. What is the vapor pressure of a solution made by adding 164 g of glycerin to 325 mL of H2O at 39.8°C? The vapor pressure of pure water at 39.8°C is 54.74 torr and its density is 0.992 g/cm3.

### chem

Determine the volume of 0.240 M KOH solution required to neutralize each of the following samples of sulfuric acid. The neutralization reaction is shown below. H2SO4(aq) + 2 KOH(aq)--> K2SO4(aq) + 2 H2O(l) (a) 26 mL of 0.240 M H2SO4 thanks

### Science

Stacy has .55kg water sample at 1 atm pressure and 40 degrees celsius. She heats it to 90 degrees Celsius, maintaining constant pressure. How much heat was absorbed by the solution during the course of this operation? (CP of H2O (l) = 4.18 J/g )

### ap chem

Bismuth can be electrolytically reduced according to the following reaction: BiO(+)+ 2H(+)+ 3e¯ >>> Bi + H2O How many grams of bismuth can be reduced by applying a 5.60 A current for 23.8 min. to a solution containing BiO+ ions (assuming 100% efficiency)?

### Chemistry

a 15ml sample of sulfuric acid was titrated against a solution of .0100 mol per litre of sodium hydroxide. to bring about neutralization, 25.00 ml of sodium hydroxide solution was required. calculate the concentration of the sulfuric acid

### chemistry

An isotonic solution contains 0.86% by mass per volume. Calculate the percent mass per volume for an isotonic solution of KCl at 30 degrees C. Assume a van't Hoff factor of 1.9.

### CHEM-102

Calculate the pH of a solution prepared by mixing 10.00mL of 0.50M NaOH and 20.00mL of 0.50M benzoic acid solution. (Benzoic acid is monoprotic; its ionization constant is 6.7x10^-5).

### Science

100ml of h2s04 solution having molarity 1M and density 1.5g/ml is mixed with 400ml of water. Calculate final molarity of h2s04 solution if final density 1.25g/ml. Ans is 0.227M

### chemistry

The standard enthalpy of formation at 298k for ccl4,h2o,co2,hcl are -22.5,-57.8,-94.1 and-22.1 kcal/mol.calculate ▲rH FOR reaction ccl4+2h2o→co2+HCL