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February 25, 2017

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

Chemistry
22mL of hydrogen was collected over wter at 19C and 745mmHg. What mass of magnesium is reacted (1:1 mole ratio)
Sunday, April 20, 2014 by Brett

Chemistry
A student intend to prepare 200ml of 0.3M NaCl solution . The mass in gram of NaCl needed to prepare solution is ?!
Sunday, April 20, 2014 by Mariam

Chemistry
To remove temporary hardness we may use ?!!!
Sunday, April 20, 2014 by Mariam

Chemistry
A water sample has TDS of 6000mg/l and the total hardness f 60mg/l , the water can be classified as ........
Sunday, April 20, 2014 by Mariam

Chemistry
The mass of watch glass is 24.5 g , the mass of watch glass plus white crystals befor drying is 29.1g , and the mass of watch glass and white crystals after drying 27.9 , thus the mass of the white crystals is !????!
Sunday, April 20, 2014 by Mariam

Chemistry
If we put a drop of acid in a cup of natural water , the PH will ?
Sunday, April 20, 2014 by Mariam

Chemistry
1.2g of NaCl as used to prepare 200 ml solution , what is the molar concentration of NaCl in solution ?
Sunday, April 20, 2014 by Mariam

Chemistry
A student mixed 40ml of 0.2m Na2co3 solution with 50 ml f 0.25M cacl2 solution , what is the except number of moles of naclkkw that I will be formed ?
Sunday, April 20, 2014 by Mariam

Chemistry
The measured experimental volume of ascetic acid in a sample of vinegar was 7% and the manufacture claimed volume is 5.8% , what is the percentage error ?
Sunday, April 20, 2014 by Mariam

Chemistry
What are the Salts are taken into consideration in the calculation of the total alkalinity ????
Sunday, April 20, 2014 by Mariam

Chemistry
The separate suspended solid from a solution , we may use .......
Sunday, April 20, 2014 by Mariam

Chemistry
In TDS experiment , the mass of the empty beaker was 25.683g , and the mass of the beaker after water evaporated 25.687 g , if the volume of the sample 50 ml , then the TDS of the water sample is ?
Sunday, April 20, 2014 by Mariam

Chemistry
In an experiment we have 4 liters of AlAin water in contain or A , and 2 liters of dubai water in contain out B . The alkalinity of water in container A and the alkalinity of water in container B are 50 and 150mg/l as caco3 ,,respectively the alkalinity of water B is 7
Sunday, April 20, 2014 by Mariam

Chemistry
In the. Reaction (Na2co3+CaCl2-->2NaCl+caco3) The precipitate is :
Sunday, April 20, 2014 by Mariam

chemistry
Calculate the enthalpy change, ÄH DeltaH, for the process in which 12.7g g of water is converted from liquid at 7.3 ∘ C \, ^\circ C to vapor at 25.0 ∘ C \, ^\circ C . For water, ÄH vap \Delta H_{\rm vap} = 44.0kJ/mol kJ/mol at 25.0 ∘ C \, ^\circ C and s s...
Sunday, April 20, 2014 by ntombiningi

Chemistry
If the equilibrium constant for a reaction A + B <----> C + D is K, which is true of the equilibrium constant K* for the reaction C + D <----> A + B under the same conditions? A) K* = K B) K* = 1/K C) K* = 1 - K D) K* = 1 - (1/K) E) K* = 1 + K
Sunday, April 20, 2014 by Chloe

Chemistry
Predict how the entropy of the substance is affected in the following processes: a) O2 (g,200 kPa, 300k) --> O2 (g, 100, 300k) b)Br2 (l, 1 bar, 25 degree C) --> Br2 (g, 1 bar, 25 degree C) C)Fe (s, 1 bar, 250 degree C)--> Fe(s, 1 bar, 25 degree C) will entropy either ...
Sunday, April 20, 2014 by Alexis

Chemistry need help
using standard potentials given in the appendices calculate the standard cell potentials and the equilibrium constants for the following reactions. Zn(s)+( Fe^2+(aq)) ---> (Zn^2+(aq))+ Fe(s) If anyone can show work, then I can do the rest of my homework by looking at this ...
Saturday, April 19, 2014 by Kader

CHEMISTRY HELP !!!!
As a standard voltaic cell runs, it "discharges" and the cell potential decreases with time. Explain.
Saturday, April 19, 2014 by Tim

chemistry
what is the concentration of phosphate in the original lake water sample if the unknown lake water sample
Saturday, April 19, 2014 by Anonymous

Chemistry
a) 45.02% of the sample remains after 85 days. Consider how you can use the percent of Ir-192 remaining and the number of days to calculate the mass remaining after 85 days.
Saturday, April 19, 2014 by ACDub

Chemistry
What is the activity of a 18.9 μCi sample of carbon-14 in becquerels?
Saturday, April 19, 2014 by ACDub

CHEMISTRY HELP !!!!
a.) which of the following reactions should have the larger emf under standard conditions & why? CuSO4 (aq) + Pb (s) goes to PbSO4 (s) + Cu (s); Cu(NO3)2 (aq) + Pb(s) goes to Pb(NO3)2(aq) + Cu(s) b.) Calculate delta G for the reaction.
Saturday, April 19, 2014 by Ali

chemistry first year
20L of N2 and 100 L of H2 are reacted to produce NH3 what is the decrease in the V of the mixture N2+3H2--> 2NH3 Ans me with reason
Saturday, April 19, 2014 by gulzara

chemistry first yera
A 0.4 g sample of monobasic acid requires 16cm3 of 0.1 mol per dm3 of NaOH for complete neutralization . what is the relative mass of the acid?? Plz ans me urgent
Saturday, April 19, 2014 by gulzara

Chemistry
A flask was immersed in 350 g of water at 25 degrees C. Steam at 100 degrees C was passed into this flask, and eventually condensed into water at 100 degrees C. If the temperature of the water surrounding the flask was raised to 70 degrees C, how many grams of steam must have ...
Friday, April 18, 2014 by Amanda

chemistry
what type of reaction occurs Fe3O4 + 4H2 → 3Fe + 4H2O
Friday, April 18, 2014 by Kyle

Chemistry
A 1.0 liter flask is filled with a mixture of two gases at 20. oC until a pressure of 14.43 atm is established. If 0.40 grams of the mixture is hydrogen, how many moles are there of the other gases?
Friday, April 18, 2014 by Carrie Boom

Chemistry
A sample of a gas has a volume of 250. mL at 2.10 atm and 227 oC. What volume will it have at standard temperature and pressure (STP)?
Friday, April 18, 2014 by Carrie Boom

chemistry
what is the pH of 0.80 M NaCN? what is the pH of 0.80 M NaCN? What is the concentration of HCN in the solution? I did this so far: I 0.8..... 0....0 C -x.......x....x E 0.8-x....x....x (x)(x)/0.8-x How do I solve for x?
Friday, April 18, 2014 by Jenny

Chemistry
Help please: A 0.199-g sample of unknown metal (X) reacts with hydrochloric acid to produce 88.5 mL of "wet" gas at 20 °C and 754 mm Hg. What is the unknown metal (X)? (The vapor pressure of water at 20 °C is 18 mm Hg.) X(s) + 2 HCl(aq) → XCl2(aq) + H2(g) (Would Mg be ...
Thursday, April 17, 2014 by Ally

chemistry
How many gramsof sodium carbonate are neededto make1.30l of0.890m
Thursday, April 17, 2014 by shae

chemistry
in the reaction Al2O3= Al+O2 if 742.5 grams of Al2O3 are used how many mols of Al will be produced?
Thursday, April 17, 2014 by Jake

chemistry
Find the a)partial pressure of ethylene oxide and b)the total gas pressure, after 30 hours in a reaction vessel at 415C if the initial pressure of ethylene oxide is 782mmHg. k= 2.05x 10^-4 t(1/2)=56.3 Part A) I converted hours to seconds, and used the formula ln(Pa)t = 108000s...
Thursday, April 17, 2014 by mae

Chemistry
How many nonbonding electron pairs are in an oxygen molecule? I drew it but im unsure if Im correct in saying it has 2 nonbonding electron pairs.
Thursday, April 17, 2014 by Ally

Chemistry
Which of the following statements is true regarding a covalent bond in CO? Valence electrons are transferred to the oxygen atom. The bond length is less than the sum of the two atomic radii. Bonding electrons are stationary in the CO molecule. all of the above none of the above
Thursday, April 17, 2014 by Lue

Chemistry
If the solubility constant for Ag2CO3 is equal to 8.1x10^-12 how many grams of Ag2CO3 will dissolve in a .0001 M solution of Na2CO3?
Thursday, April 17, 2014 by Jack

Chemistry
Ethanol will combust according to the following equation: C2H5OH(l)+3O2(g)->2CO2(g)+3H2O(l) How many liters of air are required to combust 120.1 g of ethanol at 26.4C and 789.5 mmHg. Assume air is 21% O2 by volume. I cannot find my error - professor states answer as 882.6...
Thursday, April 17, 2014 by Joe

chemistry
How many calories will 45 grams of water release when it changes fom 85c to 30c?
Thursday, April 17, 2014 by mark

Chemistry
At 25 C, RT/F = (8.314 J/mol/K *298 K) /(96500 C/mol) =0.0257 volts. My textbook lists 0.0592. What am I doing wrong?
Thursday, April 17, 2014 by Shannon

Chemistry pH
A 0.60 M solution of a weak acid, HA, has a pH of 3.72. What is the percentage ionization of the acid? What is the value of Ka for the acid?
Thursday, April 17, 2014 by Penny

Chemistry
How would I graph this: (I don't understand the whole with [1/volume] (units=1/mL) on the X-axis ) According to Boyle's Law, pressure is inversely proportional to volume, so prepare a graph of the data, with [1/volume] (units=1/mL) on the X-axis and pressure (atm) on the Y-...
Thursday, April 17, 2014 by Ally

Chemistry
Help please? 1)A sample of propane gas occupies 625 cm3 at 20.0 °C and 750 torr. What is the final volume in cubic centimeters at -80.0 °C and 750 torr? 2)If oxygen gas is collected over water at 25 °C and 775 torr, what is the partial pressure of the O2? The vapor pressure...
Wednesday, April 16, 2014 by May

Honors chemistry
How much heat (in kcal) is released when 62.2g of water at 0 degreesC freezes?
Wednesday, April 16, 2014 by Hayden

Chemistry
When given the equation 2Na+Cl2=2NaCl. How many liters of Cl2 will it take to react completely with 63.0 grams of Na?
Wednesday, April 16, 2014 by Andrew

Chemistry
Ethylamine, CH3CH2NH2, has a strong, pungent odor similar to that of ammonia. Like ammonia, it is a Brønsted base. A 0.10 M solution has a pH of 11.87. Calculate the Kb and pKb for ethylamine. What is the percentage ionization of ethylamine in this solution?
Wednesday, April 16, 2014 by Anonymous

Chemistry
A 0.60 M solution of a weak acid, HA, has a pH of 3.72. What is the percentage ionization of the acid? What is the value of Ka for the acid?
Wednesday, April 16, 2014 by Anonymous

chemistry
Which of the following statements is true concerning the titration of a weak base by a solution of hydrochloric acid? Question 9 options: At the equivalence point, the pH is 7. At the equivalence point, there is excess hydrochloric acid. At the equivalence point, the pH is ...
Wednesday, April 16, 2014 by Anonymous

Chemistry
what is the pH of 0.80 M NaCN? What is the concentration of HCN in the solution?
Wednesday, April 16, 2014 by Anonymous

chemistry
Baking soda is sodium bicarbonate (NaHCO3). When you heat baking soda, it breaks down into sodium carbonate powder (Na2CO3), water vapor, and carbon dioxide. The enthalpy of this reaction is 129 kJ. a. Write a correct, balanced thermochemical equation for this reaction. (...
Wednesday, April 16, 2014 by Anonymous

chemistry
Propionic acid has a ka of 1.3x10^(-5), 50.0ml of a buffer solution having a pH of 4.65 is to be prepared using a 0.20 M solutions of propionic acid and sodium propionate. How many ml of each of these solutions must be mixed? Thanks in Advanced !
Wednesday, April 16, 2014 by Aria

chemistry
a mixture of N2, O2 and Ar have mole fractions of 0.25, 0.65, and 0.10, respectively. What is the pressure of N2 if the total pressure of the mixture is 3.9 atm?
Wednesday, April 16, 2014 by Anonymous

College Chemistry (DrBob222)
The decomposition of HCO2H follows first-order kinetics. HCO2H(g) CO2(g) + H2(g) The half-life for the reaction at a certain temperature is 44 seconds. How many seconds are needed for the formic acid concentration to decrease by 73%?
Wednesday, April 16, 2014 by Ana

chemistry - (Dr. Bob222)
The rate constant for a second order reaction has the value of 2.5 x 10–3 L·mol–1·s–1. If the initial concentration of reactant is 3.5 mol·L-1, what will be the molar concentration of the reactant after 2.5 minutes?
Wednesday, April 16, 2014 by Ana

CHEMISTRY HELP !!!!
find kb or ka value for ZnCl2 show work! Thanks!
Wednesday, April 16, 2014 by Nane

Chemistry - Science (Dr. Bob222)
Consider the kinetic data given in the table below for the first order reaction: What is the value of the activation energy? A_2_--> 2A Expt. Initial [A2] Temp. Initial Rate mol/L (°C) [A2]·s–1 1 0.10 100 1.2 x 10–3 2 0.20 200 4.8 x 10–3 3 0.15 ? 4.5 x 10–3
Wednesday, April 16, 2014 by Ana

Chemistry - Science (Dr. Bob222)
Consider the kinetic data given in the table below for the first order reaction: What is the value of the activation energy? A_2_--> 2A Expt. Initial [A2] Temp. Initial Rate mol/L (°C) [A2]·s–1 1 0.10 100 1.2 x 10–3 2 0.20 200 4.8 x 10–3 3 0.15 ? 4.5 x 10–3
Wednesday, April 16, 2014 by Ana

Chemistry
When a sample of potassium nitrate is heated, oxygen gas is produced. This gas, collected in a 750 milliliter flask, has a pressure of 2.8 atmosphere and the temperature is recorded to be 53.6°C. How many moles of oxygen gas are produced in this reaction? (R = 0.08205 L atm/K...
Wednesday, April 16, 2014 by Brina

Chemistry
An equilibrium mixture in a 10.0 L flask contains 7.0 mol HI(g) and 1.0 mol each of I2(g) and H2(g). If 2.5 mol H2, 5.0 mol I2 and 2.0 mol HI are added to that equilibrium mixture how many moles of each gas will be present when equilibrium is reestablished?
Wednesday, April 16, 2014 by Jon

Chemistry
Write the balanced net ionic equation for the following? a) Copper metal and zinc ion b) zinc and cupric ion c) Copper metal and hydrogen ion d) zinc metal and hydrogen ion e) iron metal and hydrogen ion f) Chlorine (Cl2) and bromide ion (Br-) g) Chlorine (Cl2) and iodide ion...
Wednesday, April 16, 2014 by Shannon

Chemistry
Write the balanced net ionic equations for the reactions of the halogens with copper metal. The halogens are oxidizing agents and the copper metal is a reducing agent. a) Bromine (Br2)+copper metal (Cu) b) Iodine (I2) + copper metal (Cu) Based on your observations and ...
Wednesday, April 16, 2014 by Caroline

Chemistry
Explain how you woud make 200.0 g of a .900 percent by mass solution of salt (NaCl in water)
Wednesday, April 16, 2014 by Jakub

Chemistry
A column of mercury in a barometer is 767.3 mm Hg high. Note, that in order for the pressures to be equal, density and height of a column are inversely proportional, therefore, (den1)(h1)=(den2)(h2). The density of mercury is 13.6 g/mL and the density of water is 1.00g/mL. a) ...
Wednesday, April 16, 2014 by Carly

Chemistry
List all the quantum numbers for each of the 9 electrons in fluorine n L m sub L m sub s 1. 2. 3. 4. 5. 6. 7. 8. 9.
Wednesday, April 16, 2014 by Anonymous

Chemistry
Which halogen has the lowest electron affinity?
Wednesday, April 16, 2014 by Anonymous

Chemistry
Good morning, I am looking for help in figuring out how to solve this problem, knowing that the magnetic field was just calculated to be 9.39 tesla. Is there a specific formula and is there any information I'm missing to be able to solve this question? What is the resonant ...
Wednesday, April 16, 2014 by NP

Chemistry
Calculate Kc. CH_4(g) + H_2O(g) <-> CO(g) + 3H_2(g) Kp= 7.7 x 10^24 at 298K. Should I use the formula Kp= Kc(RT)^Deltang If so I have no idea where to start.
Wednesday, April 16, 2014 by Savannah

Chemistry Help
How many grams of silver will be obtained when an aqueous silver nitrate solution is electrolyzed for 22.0min with a constant current of 2.28A ?
Wednesday, April 16, 2014 by Michelle D.

Chemistry
The reaction has an equilibrium constant of Kp=2.26x10^4 at 298 K. CO(g) + 2H_2(g) <-> CH_3OH(g) Calculate Kp for the reactions and predict whether reactants or products will be favored at equilibrium. A. CH_3OH(g) <-> CO(g) + 2H_2(g) B. 1/2CO(g) + H_2(g) <->...
Wednesday, April 16, 2014 by Savannah

chemistry
a 0.0500 mol sample of a nutrient substance is burned in a bomb calorimeter containing 2.00 x 10^2g H2O. If the formula weight of this nutrient substance is 114g/mol, what is the fuel value (in nutrient Cal) if the temperature of the water increased 5.70C
Tuesday, April 15, 2014 by ana

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 ...
Tuesday, April 15, 2014 by lisa

Grade 12 Chemistry
When 50.0 mL of 1.0 mol/L hydrochloric acid is neutralized completely by 75.0 mL of 1.0 mol/L sodium hydroxide in a coffee-cup calorimeter, the temperature of the total solution changes from 20.2 to 25.6. Determine the quantity of energy transferred, q, and state whether the ...
Tuesday, April 15, 2014 by Vanessa

chemistry
What is the value of x for the following reaction if E∘=1.43V and ΔG∘ = -276kJ ? A+B^x+→A^x++B
Tuesday, April 15, 2014 by Anisha

Chemistry
Under identical conditions, separate samples of O2 and an unknown gas were allowed to effuse through identical membranes simultaneously. After a certain amount of time, it was found that 4.92 mL of O2 had passed through the membrane, but only 3.04 mL of of the unknown gas had ...
Tuesday, April 15, 2014 by Peter

chemistry
Determine ΔSuniv for the following equation: Ca2+ (aq) + SO42- (aq) → CaSO4 (s)
Tuesday, April 15, 2014 by Kaitlin

CHEMISTRY HELP !!!!
the following statement is false. Rewrite that it makes a correct statement about free energy. a. ΔGuniverse > 0 for any spontaneous process.
Tuesday, April 15, 2014 by Patrick

Chemistry
What is the pH of a solution that has a concentration of hydronium ions that is 1.8 × 10-4 molar H3O+? Show, or explain, the work used to solve this problem.
Tuesday, April 15, 2014 by Shanetra

chemistry
A procedure calls for 100ml of 20% H2SO4, SG=1.14. How much of the concentrated acid (98%), SG=1.84, must be diluted with water to prepare 100ml of acid of the required strength?
Tuesday, April 15, 2014 by chantal

chemistry
Determine the mole fraction of each substance in a solution containing 36.0g H2O and 46g glycerin, C3H5(OH)3
Tuesday, April 15, 2014 by chantal

chemistry
If 1.50mol of oxygen gas exerts a pressure of 1500mmHg at 20∘C, what is the volume in liters?
Tuesday, April 15, 2014 by May

Chemistry
1. How would you sketch the probable products of the reaction of the cis and trans with each reagent other than AgNO3? _____ with en _____ with NH3 ____ with KSCN cis: trans: (NOTE: What are the differences between cis and trans and its formation?) 2. How exactly would you ...
Tuesday, April 15, 2014 by Hannah

Chemistry
What volume in liters of C3H7Cl is produced if 400.0g of C3H8 (propane) reacts with excess chlorine gas according to the equation C3H8+ Cl2 --> C3H7Cl+HCl
Tuesday, April 15, 2014 by Megan

chemistry
what volume of 2.0 M NaCl is required to prepare 150 mL of 0.10 M NaCl?
Tuesday, April 15, 2014 by Rehimina

chemistry
There are two different oxides of copper produced as a result of this reaction. They are copper(I) and copper(II) oxide. If copper is changed to copper(I) oxide the percentage changed in mass is 12%. If copper is changed to copper(II) oxide the percentage change in mass is 25...
Tuesday, April 15, 2014 by Betty

Chemistry, CO2 aq+H2O->H2CO3!
How many grams of CO2 are needed to neutralize a 5 liters water with a pH of 11 to 7? under the following conditions: P: 4000 psi, T:230 oF Note: CO2 is a one of oil reservoir fluid components with mole percent 0f 3.6%. thanks a million
Monday, April 14, 2014 by Ramtin

chemistry
A ground water source contains 2.5 mg of F- ion per liter. a) what is the concentration of F- ions in moles per liter? b) will CaF2 (Ksp = 2E-10) precipitate when the concentration of Ca2+ = 5.0E-3M?
Monday, April 14, 2014 by parker

chemistry
A sample of hydrogen chloride gas occupies 0.550L at STP. What is the pressure in atm if the volume is 7.50×10−2L at 20∘C?
Monday, April 14, 2014 by ally

statistics
Leslie took two midterm exams and earned the following scores: 82 on the chemistry exam (class distribution: μ = 75, σ = 6.25) and 63 on the physics exam (class distribution: μ = 59, σ = 3.57). Rounding to two decimal points, on which exam should Leslie get...
Monday, April 14, 2014 by Sally

Chemistry
What mass of lithium phosphate is needed to prepare 500.0 mL of a solution having a lithium ion concentration of 0.1385 M?
Monday, April 14, 2014 by Chris

Chemistry
Vinegar is a solution of acetic acid, CH3COOH, dissolved in water. A 4.69 g sample of vinegar was neutralized by 32.97 mL of 0.100 M NaOH. What is the percent by weight of acetic acid in the vinegar?
Monday, April 14, 2014 by Chris

Chemistry
What mass of hydrogen gas is produced when a 7.43 g chunk of zinc dissolves in 500.0 mL of 1.200M HCl?
Monday, April 14, 2014 by Chris

Chemistry
Based on the cell reaction: Zn(s)+Cu2+(aq)→Zn2+(aq)+Cu(s) Under standard conditions, what is the maximum electrical work, in joules, that the cell can accomplish if 55.0g of copper is plated out? Wmax=______ J
Monday, April 14, 2014 by Rebecca

Chemistry
Given the following half-reactions and associated standard reduction potentials: AuBr−4(aq)+3e−→Au(s)+4​Br−(aq) E∘red=−0.858V Eu3+(aq)+e−→Eu2+(aq) E∘red=−0.43V IO−(aq)+H2O(l)+2e−→I&#​8722...
Monday, April 14, 2014 by Rebecca

Chemistry
A voltaic cell utilizes the following reaction: 2Fe3+(aq)+H2(g)→2Fe2+(aq)+2H+(aq).​ What is the emf for this cell when [Fe3+]= 3.70M , PH2= 0.95atm , [Fe2+]= 7.0×10−4M , and the pH in both compartments is 4.05? Express your answer using two significant ...
Monday, April 14, 2014 by Rebecca

Chemistry
The problem is: Calculate the standard free-energy change for the following reaction at 25 degrees Celsius. 2Au^+3(aq) + 3Cr(s)-> 2Au(s) + 3Cr^+2(aq) I worked it out, getting half reaction: Au^3+ + 3e- -> Au; E = 1.498 Cr^3+ + 3e- -> Cr; E = -0.74 Ecell = 1.498 - (-0....
Monday, April 14, 2014 by Tiffany

General Chemistry
The problem is: Calculate the standard free-energy change for the following reaction at 25 degrees Celsius. 2Au^+3(aq) + 3Cr(s)-> 2Au(s) + 3Cr^+2(aq) I worked it out, getting half reaction: Au^3+ + 3e- -> Au; E = 1.498 Cr^3+ + 3e- -> Cr; E = -0.74 Ecell = 1.498 - (-0....
Monday, April 14, 2014 by Tiffany

Chemistry
A 4.379 g sample of MgCl2 is dissolved in enough water to give 750.0 mL of solution. What is the chloride ion concentration in this solution?
Monday, April 14, 2014 by Chris

Chemistry
Balance the following equation in basic solution. Phases are optional. I{-}+IO4{-} --> I3{-}+IO3{-}
Monday, April 14, 2014 by ACDub

CHEMISTRY HELP !!!! Show work please!
Compute the energy released in kilojoules when the sun converts 1.00 metric ton into energy. NOTE: 1 metric ton = 1000 kg.
Monday, April 14, 2014 by Patrick

chemistry help~~~~ Please!!!
Sodium-24, t1/2 = 15.0 hr, can be used to study the sodium balance in animals. If a saline solution containing 25 μg of 24^Na is injected into an animal, how long can the study continue before only 1 μg is left? Show work please!
Monday, April 14, 2014 by Kim

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