Thursday
August 21, 2014

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

Post a New Question | Current Questions

chemistry
calculate the percentage by mass of oxygen in trioxonitrate(v) acid
Sunday, June 15, 2014 at 5:27pm

Chemistry
In aqueous solution, hydrochloric acid, HCl, and sodium carbonate, Na2CO3 react to produce gaseous carbon dioxide, CO2, water, H2O and sodium chloride, NaCl. A 10.0 g impure sample of Na2CO3 is dissolved completely in water; then treated with 3.00 mol L−1 HCl to evolve ...
Sunday, June 15, 2014 at 3:36pm

chemistry
calculate the percentage by mass of ozygen in trioxnitrate5 acid H-1, N-14, O-16
Sunday, June 15, 2014 at 1:03pm

chemistry
To 50 mL of this buffer, 10.0 mL 0.76 M soium hydroxide was added, what is the pH of the resulting solution after equilibrium has been re-established
Sunday, June 15, 2014 at 6:47am

Chemistry
Benzene sulfonic acid, C6H5SO3H, is a strong acid and will neutralise sodium hydroxide solution (a 1:1 molar ratio). Benzene sulfonic acid crystals (y grams) were weighed into a titration flask and titrated against sodium hydroxide solution (1.0 M) and needed a volume of 26.2 ...
Sunday, June 15, 2014 at 5:07am

Chemistry
how many millimeter should be taken out to prepare 0.5 normal HCL solution of 200 ml. density=1.18, purity 37% please response soon
Sunday, June 15, 2014 at 1:50am

chemistry
two metals (copper and aluminum ) were placed into two separate beakers which both contained 0.5M CaCl2. Give a detailed description as to what might observed in each beaker as time progressed
Saturday, June 14, 2014 at 11:53am

CHEMISTRY
WHEN CAP OF SOFT DRINK IS REMOVED THEN ITS MASS FIRST INCREASES AND THEN DECREASES WHY?
Friday, June 13, 2014 at 11:17am

physical science(chemistry change)
Experiment of tiratic oxilic acid wih mass 4,5g and volume of 25ml,nd concentration of 0,05mol.dm.3 against volume of 14ml and 1,79mol.dm3 sodium hydoxide to determine the concentration of sodium hydroxide,,show all the working,aim,results,observation of result,discussion
Thursday, June 12, 2014 at 12:05pm

physical science(chemistry change)
Experiment of tiratic oxilic acid wih mass 4,5g and volume of 25ml,nd concentration of 0,05mol.dm.3 against volume of 14ml and 1,79mol.dm3 sodium hydoxide to determine the concentration of sodium hydroxide,,
Thursday, June 12, 2014 at 12:04pm

science-chemistry
Calculate the number of moles of solute present in 450. g of an aqueous NaCl solution that is 0.565 % NaCl by weight
Thursday, June 12, 2014 at 11:11am

Chemistry
If you need to make a solution of 1.0L at 2.5M citric acid and you only have 45mL of 5.0M citric acid, do you have enough for your experiment? If a mathematical procedure is involved, please explain to me; I really want to grasp this chemistry concept.
Wednesday, June 11, 2014 at 8:18pm

CHEMISTRY
WHEN CAP OF SOFT DRINK IS REMOVED THEN ITS MASS FIRST INCREASES AND THEN DECREASES
Wednesday, June 11, 2014 at 2:43pm

Chemistry
what is the mass of nh4cl that must dissolve in 100. grams of h2o to produce a saturated solution at 70 degrees celsius
Wednesday, June 11, 2014 at 11:32am

chemistry
what's the discussion for determine BaCl2.2H2O in lab report
Wednesday, June 11, 2014 at 11:27am

chemistry
if an excess of nitrogen is reacted with 3.41 g of hydrogen, how many grams of ammonia can be produced?
Wednesday, June 11, 2014 at 9:21am

chemistry
What is the Ka of a weak acid (HA) that produces a pH of 3.45 with 0.1M? 2.54E-3 3.45E-3 1.27E-6 3.56E-3 5.48E-4
Tuesday, June 10, 2014 at 9:22pm

chemistry
Consider the equation 2kclo3(s) -> 2kcl(s)-1302(g). 3.00-g sample kclo2 is decomposed and the oxygen at 24.0 and 0.982 its either, 911, 304, or 608
Tuesday, June 10, 2014 at 5:45pm

chemistry
A sample of gas (1.9 mol) is in a flask at 21 °C and 697 mm Hg. The flask is opened and more gas is added to the flask. The new pressure is 795 mm Hg and the temperature is now 26 °C. There are now __________ mol of gas in the flask.
Tuesday, June 10, 2014 at 12:49pm

Chemistry
what is the pH solution in which 15 mL of 0.10 M NaOH has been added to 25 mL of 0.10 M HCl
Tuesday, June 10, 2014 at 10:18am

Chemistry
Consider the following equilibrium. 2 SO2 (g) + O2 (g) 2 SO3 (g) The equilibrium cannot be established when __________ is/are placed in a 1.0-L container.
Monday, June 9, 2014 at 9:07pm

CHEMISTRY
How much 0.200 M KOH is required to completely neutralize 25.0 mL of 0.150 M HClO4?
Monday, June 9, 2014 at 7:49pm

CHEMISTRY
How many liters of softened water, containing a sodium concentration of 0.050% sodium by mass, have to be consumed to exceed the FDA recommendation? (Assume a density of 1.0 g/mL for water.)
Monday, June 9, 2014 at 7:34pm

Chemistry
A butane lighter had a mass of 24.643 grams before lighting and a mass of 24.592 grams after. How many mL of CO2 were produced? Assume STP.
Monday, June 9, 2014 at 6:01pm

chemistry 2
What is the value for ∆Soreaction for the following reaction, given the standard entropy values? 2 Al (s) + 3Cl2(g) 2AlCl3(s) a.-503 J/K b.+503 J/K c.-140 J/K d.+140 J/K
Monday, June 9, 2014 at 4:57pm

Chemistry
5.2 grams of magnesium metal are place in 400.0 mL of 1.0 M hydrochloric acid. The balanced equation for the reaction is: Mg + 2HCl = MgCl2 + H2. How many moles of H2 gas were produced?
Monday, June 9, 2014 at 3:37pm

Chemistry
I need help on these three questions. For all three of them you're supposed to write a balanced equation for each neutralization. Then, to find the concentrations of the unknown solutions if the following reactions are found to reach equivalence by titration. The three ...
Monday, June 9, 2014 at 2:03pm

Chemistry
How would you prepare pure dry crystals of pottasium trioxonitrate (v) ?.
Monday, June 9, 2014 at 1:52am

Chemistry
If 3.50 mol of A is mixed with 0.750 mol of B and the final pressure of the mixture is 3.25 atm, what are the partial pressures of A and B
Sunday, June 8, 2014 at 11:09pm

Chemistry
27. Excess exposure to nuclear radiation can cause harm. All of the following statements about radiation are true EXCEPT A. Radiation can damage living tissue because of the high energy associated with the radiation. B. Radiation can damage biological molecules by knocking an ...
Sunday, June 8, 2014 at 9:55pm

Chemistry
what volume (mL) of 0.0962M NaOH is required to neutralize 10.0mL of 0.128M H2SO4? I got 26.6mL
Sunday, June 8, 2014 at 9:28pm

Chemistry
23. In a chemical reaction, dynamic equilibrium occurs when the rate of the forward reaction becomes precisely equal to the rate of the reverse reaction. All of the following statements are true EXCEPT A. A dynamic equilibrium occurs when the reaction is more than 50 percent ...
Sunday, June 8, 2014 at 5:24pm

Chemistry
I posted this last night, A 0.500L vessel initially contains 0.0125 mol of H2S2 . Find the equilibrium concentrations of H2 and S2. Kc = 1.67 x 10^-7 2 H2S <--> 2 H2 + S2 I have come up with this equation so far, but I am lost now because I don’t even know if this ...
Sunday, June 8, 2014 at 11:22am

chemistry
If the pH of an aqueous solution is 5, what is the OH− concentration?
Sunday, June 8, 2014 at 11:16am

chemistry
What is the pH of a water solution at 25◦C in which the hydroxide ion concentration is 9.8 × 10−6 mol/L?
Sunday, June 8, 2014 at 11:15am

chemistry
Calculate the [H+] for a solution with [OH−] = −80 M. 1x10*-14/-80=-log(answer) How would I do this since I can not take the negative log of the previous anwser
Sunday, June 8, 2014 at 11:12am

chemistry
Urea (CO(NH2)2) can react with water to form CONH2NH+ 3 and a hydroxide ion. Which statement is true for this reaction?
Sunday, June 8, 2014 at 11:05am

chemistry
Calculate the pH of an aqueous solution of 11.5 mg of KOH dissolved in 56 mL of solution.
Sunday, June 8, 2014 at 11:00am

Chemistry/physics
The KE of a hydrogen atom's electron is 12.65 eV. Calculate the velocity of the electron? Known: KE=mv^2
Sunday, June 8, 2014 at 10:20am

chemistry
46,318.97
Sunday, June 8, 2014 at 5:54am

chemistry
calculate the mass of Cuso4.5H2O required to prepare 500 cm3 of a 0.400 m/dm-3 solution
Sunday, June 8, 2014 at 5:31am

Science - chemistry
The osmotic pressure of a solution of MgCl2 is 5.43 atm at 25 oC. How much of the salt is dissolved in 250.0 ml of water?
Sunday, June 8, 2014 at 3:14am

Science - chemistry
The SO2 present in air is mainly responsible for the phenomenon of acid rain. The concentration of SO2 can be determined by titration against a permanganate solution of known concentration as follows: SO2 + MnO4^-1 -> SO4^-2 + Mn2+ (unbalanced) Balance the equation showing ...
Sunday, June 8, 2014 at 3:03am

chemistry
i need help solving this Benzoic acid is a weak, monoprotic acid (Ka = 6.3 × 10−5). Calculate the pH and the percent dissociation of each of the following solutions of benzoic acid. Then use Le Châtelier’s principle to explain the trend in percent ...
Saturday, June 7, 2014 at 11:42pm

Chemistry
How many grams of pure H2SO4 can be obtained from 250 grams of iron ore if the ore is 82% FeS2? The reactions involved are given below: 4FeS2 + 11 O2 --> 2 Fe2O3 + 8 SO2 (95% efficient) 2SO2 + O2 --> 2SO3 (90% efficient) SO3 + H2O --> H2SO4 (90% efficient)
Saturday, June 7, 2014 at 10:29pm

Chemistry
A 0.500L vessel initially contains 0.0125 mol of H2S2 . Find the equilibrium concentrations of H2 and S2. Kc = 1.67 x 10^-7 2 H2S <--> 2 H2 + S2
Saturday, June 7, 2014 at 9:49pm

Chemistry
how would you do this question when i did it i did -log(1.0) but that is just 0 so what it the procedure to do this question Calculate the pH of a 1.0 mol/L aqueous solution of sodium benzoate. Note: Only the benzoate ion affects the pH of the solution.
Saturday, June 7, 2014 at 8:18pm

chemistry
How would you do this question: A student dissolved 5.0 g of vitamin C in 250 mL of water. The molar mass of ascorbic acid is 176 g/mol, and its Ka is 8.0 × 10−5. Calculate the pH of the solution. Note: Abbreviate the formula of ascorbic acid to HAsc.
Saturday, June 7, 2014 at 7:56pm

Chemistry
Which formula represents an organic acid? HCOOCH3 CH3CH2OH CH3COCH3 HCOOH Can you please help me
Saturday, June 7, 2014 at 4:18pm

chemistry
How are cis trans isomers used for night vision?
Saturday, June 7, 2014 at 4:08pm

chemistry
What are the differences between cis- and trans-isomers?
Saturday, June 7, 2014 at 4:00pm

Chemistry
Which formula represents an organic acid? HCOOCH3 CH3CH2OH CH3COCH3 HCOOH
Saturday, June 7, 2014 at 3:44pm

chemistry
C+HNO3=H2CO3+H2O+NO2 which type of reaction is it.
Saturday, June 7, 2014 at 5:53am

chemistry
write 63 ml in scientific notation
Friday, June 6, 2014 at 8:34pm

Chemistry
A solution of the primary standard potassium hydrogen phthalate, KHC8H4O4, was prepared by dissolving 0.4877 g of potassium hydrogen phthalate in about 50 mL of water. Titration with a KOH solution required 24.71 mL to reach a phenolphthalein end point. What is the molarity of...
Friday, June 6, 2014 at 4:25pm

Chemistry
How many grams of HCl are needed in order to make 0.500 liters of a 0.100 M HCl solution? 1.82 g 18.2 g 0.500 g
Friday, June 6, 2014 at 2:23pm

Chemistry
10.0 g of an unknown acid is titrated to the equivalent point using 65.0 ml of 0.150M KCH. Assuming the acid is monoprotic ( like HCL or HF ) , what is the molecular mass of the acid? Is it possible to find the mols of the acid? (Balanced equation & solution please!)
Friday, June 6, 2014 at 1:56pm

chemistry
Which of the following are single replacement reactions? Choose all that apply. Question 1 options: NaHCO3(s) + HCl(aq) → NaCl(aq) + CO2(g) + H2O(l) Zn(s) + 2 HC2H3O2(aq) → Zn(C2H3O2)2(aq) + H2(g) N2(g) + 3 H2(g) → 2 NH3(g) 2 AgNO3(aq) + Cu(s) → 2 Ag(s...
Friday, June 6, 2014 at 12:30pm

chemistry
What would be the change in enthalpy if you detonated 10 grams of NI3?
Friday, June 6, 2014 at 11:20am

Science - chemistry
Calculate the volume of 0.05 M NaOH which must be added to 100 cm3 of 0.05 M methanoic acid to obtain a buffer of pH 4.23. (Ka for methanoic acid = 1.77 x 10-4)
Friday, June 6, 2014 at 10:11am

Science - chemistry
Calculate the pH of a solution prepared by adding 36 cm3 of 0.15 M methanoic acid to 27 cm3 of 0.20 M NaOH. (Ka for methanoic acid = 1.77 x 10-4)
Friday, June 6, 2014 at 9:50am

help!! Chemistry
Zn + VO3 ^- --> Zn ^2+ + V^+3 Fe ^2+ + H2O2 + OH- --> Fe (OH) 3 V2O5 + I- + H^+ --> VO2 + I2 + H20 P + H+ + NO3- + H2O -->'NO + H3PO4 RedOX REACTIONS
Friday, June 6, 2014 at 8:57am

Help Chemistry
Zn + VO3 ^- --> Zn ^2+ + V^+3 Fe ^2+ + H2O2 + OH- --> Fe (OH) 3 V2O5 + I- + H^+ --> VO2 + I2 + H20 P + H+ + NO3- + H2O -->'NO + H3PO4
Friday, June 6, 2014 at 7:40am

Chemistry
10.0 g of an unknown acid is titrated to the equivalent point using 65.0 ml of 0.150M KCH. Assuming the acid is monoprotic ( like HCL or HF ) , what is the molecular mass of the acid? Is it possible to find the mols of the acid? (Balanced equation & solution please!)
Friday, June 6, 2014 at 4:29am

Chemistry
What volume of .300M HCL is required (a) to titrate 50.0 ml of 0.600 M LiOH? (B) to titrate 50.0ml of .600M Ca(OH)2 (balanced equation and solution for both please!)
Friday, June 6, 2014 at 4:25am

chemistry - please help
What solubility of hydrogen and nitrogen is in liquid ammonia? Does any formula exist for calculation a solubility of hydrogen and nitrogen in liquid ammonia or do you know specific constants or numbers for this question? Thank you for your answers.
Friday, June 6, 2014 at 4:23am

Chemistry
What is the molarity of an Acetic Acid Solution that requires 40.0 ml of 0.100M NaOH to titrate a 20.0ml sample to the end point? (Balanced equation & solution please! Thanks in advance)
Friday, June 6, 2014 at 4:21am

Chemistry
Zn + VO3 ^- --> Zn ^2+ + V^+3 Fe ^2+ + H2O2 + OH- --> Fe (OH) 3 V2O5 + I- + H^+ --> VO2 + I2 + H20 P + H+ + NO3- + H2O -->'NO + H3PO4
Friday, June 6, 2014 at 2:00am

Chemistry
For each of the following examples, decide whether it would be better to use the term molecule or formula unit. a. K2SO3 b. H2SO3 c. CCl4 d. NH4Cl
Thursday, June 5, 2014 at 8:34pm

Chemistry
calculate the amount of heat required to decompose 8 mol of NaHCO3(s) 2NaHCO3(s) + 94000 J = Na2CO3(s)+ H2O(g) + CO2(g)
Thursday, June 5, 2014 at 4:23pm

chemistry
what will be the balance chemical equation of ethanol and blood if ethanol and blood reacts to produce element z
Thursday, June 5, 2014 at 4:07pm

Chemistry
At equilibrium, what is the hydrogen-ion concentration if the acid dissociation constant is 0.000 001 and the acid concentration is 0.01M? can you help me step by step and explain?
Thursday, June 5, 2014 at 12:40pm

chemistry
At a certain temperature, Keq is 4.13 x 10^-5 for the equilibrium: 2IBr(g) ↔ I2(g) + Br2(g) Assume that the equilibrium is established at the above temperature by adding only the reactant to the reaction flask. What are the concentrations of I2 and Br2 in equilibrium ...
Thursday, June 5, 2014 at 12:20pm

Chemistry
A gas occupies a volume of 140 mL at 35.0 C and 97 kPa. What is the volume of the gas at STP? N = ( P )( V ) / ( R ) ( T ) N = ( 97.00 ) ( 140 /1000 ) / ( 8.314 ) ( 308.15 ) = 0.005300 gmol V sub STP = ( N ) ( R ) ( T sub STP ) / ( P sub STP ) V sub STP = (0.005300 )( 8.314...
Thursday, June 5, 2014 at 12:16pm

Chemistry
A gas has a volume of 590 mL at a temperature of –55.0 C. What volume will the gas occupy at 30.0 C? V1T1 = V2T2 (590 mL)(-55.0C) / (30.0C) = 1081.67 mL 273 + (-55) = 218 K 590/218 = V2/303 V2 = 590 (303/218) = 820 ml Is my work and answer correct??
Thursday, June 5, 2014 at 12:10pm

chemistry
IF ALL NITROGEN ATOMS FROM .1 MOLE nO2 AND .2 MOLE N2O4 ARE REMOVED THEN HOW2 MANY MOLES OF N2 CAN BE PREPARED FROM IT?
Thursday, June 5, 2014 at 11:10am

chemistry
if all the oxygen from 1.8 gram glucose and 9.8 H2So4 are removed and converted to o2 how many moles are prepared?
Thursday, June 5, 2014 at 11:06am

chemistry
how many carbon atoms are present in a drop of ink which falls on the paper having a wave point 0.1 mg
Thursday, June 5, 2014 at 11:02am

chemistry
what is the weight in kg of 3*10 22 molecules of NaOH
Thursday, June 5, 2014 at 11:00am

chemistry
if all the sulphur atoms from 9.8 kgh2so4 are removed and converted to s8 than how many moles of s8 can be prepared?
Thursday, June 5, 2014 at 10:58am

chemistry
if+all+nitrogen+atoms+from+.1+mole+No2+a​nd+.2+N2o4+are+removed+then+how+many+mol​es+of+n2+can+be+prepared+from+it
Thursday, June 5, 2014 at 10:54am

Chemistry
Explain why this reaction is not feasible:CH3CHO^-Na^+ + CH3C(CH3)2Cl=CH3CH2O(CH3)2OCH3. ;->Becos of ion charge of Oxygen and Na in the cpd reacting with non ionic cpd
Thursday, June 5, 2014 at 10:32am

Chemistry
how many moles of oxygen are needed to react with 3.5 moles of isopropyl alcohol, C3H7OH
Thursday, June 5, 2014 at 7:22am

Chemistry
Give reasons why the reaction between benzoylchloride and methanol do not attack carbon from the ring
Thursday, June 5, 2014 at 3:34am

chemistry
a scuba driver is using eanx32, an enhanced nitrox gas mixture. this mixture contains 32% oxygen with 68% nitrogen. if the cylinder is at a pressure of 250 kpa, what is the partial pressure of oxygen?
Thursday, June 5, 2014 at 2:40am

Chemistry
Question: Calculate the solubility (g/L) of CuBr at 25 degrees celsius in 0.0110 M CoBr2. Ksp of CuBr = 5.3*10^-9. I am capable of doing it in pure water, but I am struggling with how the two bromines in CoBr2 will affect the answer and ICE TABLE set up. Thank you!
Wednesday, June 4, 2014 at 11:51pm

Chemistry
The heat capacity of aluminum is 24.4 J/mol times degrees C. How much energy is released when 5.00 g Al is cooled from 50 degrees C to 30 degrees C. a) 2440 J b) 90 J c) 3.7 J d) 488 J I said A, but the answer sheet says that the answer is B. Can someone please explain how ...
Wednesday, June 4, 2014 at 9:52pm

Chemistry
I'm really confused on this question so if someone could show the steps and how to get the answer, that would be great. I understand that you would use delta T=Kbm, but don't know how to use the equation to find the answer. Thanks!! Calculate the boiling point of a ...
Wednesday, June 4, 2014 at 8:29pm

chemistry
15G OF NACL OCCUPY A VOLUME OF 75 Ml what is the molarity solution ?
Wednesday, June 4, 2014 at 7:58pm

chemistry
A sample of helium has a volume of 235 ml and a pressure of 565 mm Hg. What will be the pressure if the helium is compressed to 215 mL (T constant)
Wednesday, June 4, 2014 at 4:44pm

chemistry
If you mix 50 grams of NaHCO3 in 2.0 liters of water, calculate molarity & molality
Wednesday, June 4, 2014 at 7:47am

chemistry
A sample contains Hydrogen atom ,He+ ion, Li2+, & Be3+ ion. In H atom electron is present in 8th orbit, in He2+ e- is present in 6th orbit, Li2+ in 5th orbit& in Be3+ electron is present in 4th orbit. All the atoms are de-excited to the ground state. Calculate the total no. of...
Wednesday, June 4, 2014 at 4:36am

Chemistry
Why is it that the reaction between benzoyl chloride and methanol do attack carbon from the ring
Wednesday, June 4, 2014 at 3:19am

Chemistry
If 87.3 mL of 0.225M KOH solution is mixed with 44.4 mL of 0.313M H2SO4 solution, would the resulting mixture be acidic, basic or neutral?
Tuesday, June 3, 2014 at 11:42pm

chemistry
What is the molarity of a 28.9 g of CaCl2 dissolved in water to make up 0.78L of solution?
Tuesday, June 3, 2014 at 11:06pm

chemistry
Calculate the molarity (M) of AlCl3 in a solution prepared by adding 0.750 L of 0.7 M AlCl3 and 0.250 L of 0.1 M AlCl3 . Assume volumes are additive
Tuesday, June 3, 2014 at 8:35pm

Chemistry
Label each of the following as endothermic or exothermic A.) Products are more stable than reactants B.) Kinetic energy is converted into potential energy C.) Evaporation D.) Combustion E.) Water freezes F.) Heat seems to disappear
Tuesday, June 3, 2014 at 8:04pm

Chemistry
Check my answer please? A reaction requires 22.4 L of gas at STP. You have 45.0 L of gas at 100 kPa and 373 K. Which of the following statements is true? The gas constant is 8.31 L-kPa/mol-K. You will have an excess of gas and the reaction will occur. <--------- You will ...
Tuesday, June 3, 2014 at 7:38pm

Chemistry
I posted this question before and the answer is suppose to be 6.8 L but I keep getting 6.12 L dinitrogen pentoxide n2o5 decomposes by a first-order decomposition in chloroform solvent to yield NO2 and O2. The rate constant at 45°C is 6.2 x 10^-4 mins^-1. Calculate the ...
Tuesday, June 3, 2014 at 7:07pm

Chemistry
I: The standard reaction free energy at equilibrium is zero. II: A reaction stops when the equilibrium is reached. III: An equilibrium reaction is not affected by increasing the concentrations of products. Which of these statements is/are true?
Tuesday, June 3, 2014 at 4:19pm

Pages: <<Prev | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | Next>>

Post a New Question | Current Questions

Homework Help: Science

Search
Members