Friday
July 29, 2016

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

chemistry
A certain elementary gas is triatomic and has vapour density 48 . The atomic mass of the gas is (a) 48 (b) 96 (c) 32 (d) 16 ..
Friday, April 1, 2016 by jay

Chemistry
10.5g of zinc trioxocarbonate(iv) were heated very stronglu to a constant mass and the residue treated with excess Hcl.calculate the mass of zinc chloride
Friday, April 1, 2016 by Peace

Chemistry
10.5g of zinc was heated to a constant mass and the residue treated with excess Hcl: ZnCo3+Hcl-----ZnCl2+Co2+H2O. Calculate the mass of zinc chloride that would be obtained
Friday, April 1, 2016 by Peace

chemistry
What is the oxidation number of chlorine in Al(ClO4)3? I don't understand this question, can someone help? Thank you!
Friday, April 1, 2016 by louren

Chemistry
Why is methyl orange not suitable indicator for h2c2o4 and naoh
Friday, April 1, 2016 by Ifunanya

Chemistry
The rock in a particular iron ore deposit contains 84 % Fe2O3 by mass. How many kilograms of the rock must be processed to obtain 1100 kg of iron?
Thursday, March 31, 2016 by Aria

Chemistry
What is the pH of a solution made by mixing 1.40 mL of 0.0043 molar Sr(OH)2 with 8.90 mL of 0.0029 molar Sr(OH)2 solution?
Thursday, March 31, 2016 by Kelly

Chemistry
Suppose a saturated solution of barium fluoride contains 1.5 x 10 ^ -2 M of F-. What is the Ksp of BaF2. I know that the balanced equation of this reaction is: BaF2 (s) --> Ba2+ (aq) + 2F- (aq) There is a 1:1 ratio between BaF2 and Ba2+ and there is a 1:2 ration between ...
Thursday, March 31, 2016 by Grace

chemistry
Given the balanced equation: 2 Al + Fe2O3 → Al2O3 + 2 Fe how many grams of Al2O3 will be produced if 68.1 g Al reacts with 112 g Fe2O3?
Thursday, March 31, 2016 by Winter

chemistry
Given overall reaction: P4 + 10Cl2 ---> 4PCl5 Delta H for the reaction = ? PCl5 -----> PCl3 + Cl2 Delta H = +157 kJ P4 + 6Cl2 ----> 4PCl3 Delta H = -1207 kJ Calculate the Delta H for the overall reaction.
Thursday, March 31, 2016 by John

Chemistry
. Okay 2HgO turns into 2hg + O2. What mass of Co2 can be produced from 25.0g of Fe3O4 ?
Thursday, March 31, 2016 by Maxwell

Chemistry
How do I make 500ml of a 0.3% chlorine dioxide solution from 6.4% tablets?
Thursday, March 31, 2016 by Pam

CHEMISTRY
How would you prepare 750 ml of a 10 fold dilution of a 17 M solution of acetic acid? How would you prepare 200 ml of a 20 fold dilution of a 17 M solution of acetic acid? please explain and show me the calculations.
Thursday, March 31, 2016 by rockey

Chemistry
How do I make a 500ml amount of a 0.3% aqueous solution of chlorine dioxide
Thursday, March 31, 2016 by Pam

Chemistry
What mass of copper(ii) sulphate(GFM=159.5) is required to make 400cm3 of 0.5mol/l solution
Thursday, March 31, 2016 by Callum

chemistry
If 5.40 kcal of heat is added to 1.00 kg of water at 100⁰C, how much steam at 100⁰C is produced? Show all calculations leading to an answer. I can't figure this one out, can someone help me? Thank you!
Thursday, March 31, 2016 by louren

chemistry
You have two sealed jars of water at the same temperature. In the first jar there is a large amount of water. In the second jar there is a small amount of water. Using 3 -4 sentences explain how the vapor pressure of water in the first jar compares with the vapor pressure of ...
Thursday, March 31, 2016 by louren

chemistry
I don't understand the difference between endothermic and exothermic?
Thursday, March 31, 2016 by Carly

Chemistry
A sample of propane, C3H8, contains 10.0 moles of carbon atoms. How many total moles of atoms does the sample contain? Express the total number of moles of carbon and hydrogen numerically.
Wednesday, March 30, 2016 by Aria

chemistry
A gas occupies 5.65 L at 808 torr and 17◦C. What volume will it fill if the pressure is changed to 730 torr and the temperature is raised to 51◦C?
Wednesday, March 30, 2016 by emily

Chemistry
If the total number of electrons in the ion [M (H2O) 4] +2 is equal to 50 Whish is the atomic number of M?
Wednesday, March 30, 2016 by Kassia

Chemistry
Show how you would calculate the % yield of hydrogen if 40.0 grams of magnesium react with an excess of nitric acid producing 1.70 grams of hydrogen gas. Mg + 2 HNO3 ---> Mg(NO3)2 + H2
Wednesday, March 30, 2016 by Elizabeth

Chemistry
3.2 grams of calcium chloride reacts with 3.55 grams of sodium sulfate producing calcium sulfate + sodium chloride. Which is the reactant in excess and the excess mass? Cacl2 + Na2SO4 = CaSO4 + NaCl
Wednesday, March 30, 2016 by Kennia

Chemistry
Determine the specific mass of fluorine (F2) in g/cm³ in 20°C and 188 torr
Wednesday, March 30, 2016 by Jimmy B

chemistry concentrations
if i calculated a dilution concentration from excel to be 0.171 ppm, how do i calculate the concentration of the analyte in 64 fl oz bottle? So we pulled 10 mL out, and diluted it to 40 mL...is this right, 0.171 ppm / (10 mL/40mL) = concentration in 1 bottle?
Wednesday, March 30, 2016 by Anonymous

Chemistry
Small amounts of chlorine gas can be gener- ated in the laboratory from the reaction of manganese(IV) oxide with hydrochloric acid: 4 HCl(aq) + MnO2(s) → 2 H2O(l) + MnCl2(s) + Cl2(g). What mass of Cl2 can be produced from 41.8 g of MnO2 with an excess of HCl(aq)?
Wednesday, March 30, 2016 by Will

Chemistry
When 0.07 moles of ammonium sulfate ((NH4)2SO4) are dissolved in enough water to make 254 milliliters of solution, how many ammonium ions are present?
Wednesday, March 30, 2016 by Eva

Chemistry
How do you complete the following by writing products? #1.Ca(OH)2+MgCl
Wednesday, March 30, 2016 by Tas

chemistry
calculate the solubility of PbI2 in 0.0123M CaI2. Ksp=6.81x10^-9
Wednesday, March 30, 2016 by benji

Chemistry
How many moles are in 2.3 grams of oxygen gas.
Wednesday, March 30, 2016 by Jake

chemistry
why does the solubility of most solid substances in liquid solvents increase in temperature whereas gases reduce
Wednesday, March 30, 2016 by anonymous

chemistry
explain briefly why CuSo4 is more soluble in water than in organic solvent
Wednesday, March 30, 2016 by zainab

Chemistry
What is the pH of the solution when 50.00 mL of 0.250 M HNO3, nitric acid, has been treated with 25.00 mL of 0.400 M NaOH? Below is the work I performed, however, my professor deemed the [H3O] as incorrect. Where did I go wrong? [NaOH] = .025 L x 0.400 M = .010 mol [HNO3] = ....
Wednesday, March 30, 2016 by Alex

chemistry
what is the charge balance equation for acetic acid?
Wednesday, March 30, 2016 by lia

chemistry
For the following reaction at equilibrium, which change would shift the position of equilibrium toward forming more products? (Circle your answer(s) as there may be more than one.) 2NOBr(g) 2NO(g) + Br2(g), ∆Hºrxn = +30 kJ/mol A) Decrease the total pressure by ...
Wednesday, March 30, 2016 by maria

Chemistry
Write the balanced equation when 9 grams of water undergo electrolysis and calculate the amount of oxygen gas liberated?
Tuesday, March 29, 2016 by Ravalipriya

Chemistry
@DrBob222 I got the last question that I posted wrong and I solved it the same way. Could you show me the answer and how you got it? My test is Friday and this is a practice problem. Suppose that 30 mL of 0.5 M CsOH and 55 mL of 0.1 M NaHS are mixed. What is the K for the ...
Tuesday, March 29, 2016 by Sarah

Chemistry
A single dose of a certain antacid contains 250. mg of Mg(OH)2 and 300. mg of CaCO3. How many mmol of H+ can be neutralized by one dose of this antacid? Do not include units in your answer
Tuesday, March 29, 2016 by Chris

Chemistry
Suppose that 30 mL of 0.5 M CsOH and 55 mL of 0.1 M NaHS are mixed. What is the K for the dominant equilibrium in terms of Ka's, Kb's, Kw etc.? Ka of HS- 1/Ka of HS- Kb of OH- 1/Kb of OH- Kb of S-2 1/Kb of S-2 Kw 1/Kw There is no reaction.
Tuesday, March 29, 2016 by Sarah

Chemistry
A chemist dissolves 0.096 g of CuSO4 · 5 H2O in water and dilutes the solution to the mark in a 500-mL volumetric flask. A 10.8-mL sample of this solution is then transferred to a second 500-mL volumetric flask and diluted. What is the molarity of CuSO4 in the second ...
Tuesday, March 29, 2016 by Eva

Chemistry
A chemist dissolves 0.096 g of CuSO4 · 5 H2O in water and dilutes the solution to the mark in a 500-mL volumetric flask. A 10.8-mL sample of this solution is then transferred to a second 500-mL volumetric flask and diluted. What is the molarity of CuSO4 in the second ...
Tuesday, March 29, 2016 by Eva

Chemistry
Suppose that 85 mL of 0.4 M NaF and 50 mL of 0.4 M HCl are mixed. What is the K for the dominant equilibrium in terms of Ka's, Kb's, Kw etc.? Ka of HCl 1/Ka of HCl Ka of HF 1/Ka of HF Kb of F- 1/Kb of F- Kb of Cl- 1/Kb of Cl- Kw 1/Kw There is no reaction.
Tuesday, March 29, 2016 by Sarah

Chemistry
85.0 mL of 1.50 mol/L ammonium chloride solution is added to 250 mL of water. Calculate the molar concentration of the final solution. Using the formula C(Concentration)=n(moles)/v(Volume measured in litres.) How am I supposed to solve this question given two volumes?
Tuesday, March 29, 2016 by AlphaPrimes

Chemistry
What size container do you need to hold 0.0459 mol of N2 gas at stp
Tuesday, March 29, 2016 by Jimmy B

Chemistry
What is the OH- concentration of a solution whose pH is 12.40?
Tuesday, March 29, 2016 by Trinity

Chemistry
How many moles of oxygen (O2) are required to completely react with 27.4 mol of H2?
Tuesday, March 29, 2016 by Dylan

Chemistry
Which element has an ion that is smaller than an ion of calcium?
Tuesday, March 29, 2016 by Lisa

chemistry
A 190 mL sample of 0.293 M NaCH3CO2(aq) is diluted to 750 mL. What is the concentration of the acetic acid at equilibrium? Ka =1.8×10−5.
Tuesday, March 29, 2016 by Anonymous

AP Chemistry
A 190 mL sample of 0.293 M NaCH3CO2(aq) is diluted to 750 mL. What is the concentration of the acetic acid at equilibrium? Ka =1.8×10−5. Answer in units of mol/L.
Tuesday, March 29, 2016 by Samantha

chemistry
Experimental Design: From the work you have done this semester, choose a topic and design an experiment you would be able to perform. In your design (1) state your hypothesis, (2) identify your dependent and (3) independent variables, (4) your control conditions and (5) ...
Tuesday, March 29, 2016 by louren

chemistry
Magnesium nitride is formed in the reaction of magnesium metal with nitrogen gas in this reaction: 3 Mg(s) + N2(g) --> Mg3N2(s) How many grams of product are formed from 2.0 mol of N2 (g) and 8.0 mol of Mg(s)? i havent been able to figure this one out, can someone help me?
Tuesday, March 29, 2016 by louren

Chemistry- Dr.Bob222
Which if the folowin species is not amphoteric? a) H2SO4 b) H2PO4- c) HPO4 2- d) HSO4- e) H2O
Monday, March 28, 2016 by Nevaeh

Chemistry
We have an aqueous solution that contains 22% (by mass) of a hypothetical solute Z. The formula weight of the solute Z is 215 g/mol. The density of the solution is observed to be 1.1 g/mL. What is the molarity of Z in this solution?
Monday, March 28, 2016 by El

Chemistry
I've run into some difficulty with my chemistry homework. We went over this practise question in class today as an example. However, I wasn't able to fully grasp how to work it out. "How many grams of nitrogen form when 34.6 grams of nitrogen dioxide decomposes ...
Monday, March 28, 2016 by Kara

Chemistry
A sample of calcario and other components of the soil was intensely warm. Under these conditions, the calcario undergoes decomposition in calcium oxide and carbon dioxide. CaCO3 (s)-> CaO (s) + CO2 (g) The analysis of 71, 42 g of a sample of limestone supplied 13 g of ...
Monday, March 28, 2016 by William

Chemistry PLS HELP!!!
A student collects oxygen gas by water displacement at a temperature of 17 Celsius. A barometer reads 92.3 kPa. What is the pressure of the water vapor? Look it up on a water vapor pressure chart. What is the pressure of the oxygen gas? (Answer: ~14.0 mmHg for water, 678.3 ...
Monday, March 28, 2016 by Ana

Chemistry
Calculate the theoretical amount of .5M NaOH that it would take to neutralize approx. 2.0 g KHP. KHP is a monoprotic acid, the molar mass of KHP is 204.22 g/mol and the molar mass of NaOH is 40.00 g/mol. Answer in terms of mL. I converted g KHP to mols, then mols of KHP to ...
Monday, March 28, 2016 by Brad

chemistry
Make the conversion 8.5 x10^2 cal to Calorie 4.5x10^-1kj to calories
Monday, March 28, 2016 by lulu

Chemistry
Calculate how many grams of MgO that can be produced from 4.58 of Mg metal and 0.99 of O2 gas. Recall the balanced reaction is: 2 Mg (s) + O2 (g) 2 MgO (s) And the answers to part one were: Moles of MgO from 4.58 g Mg = 0.1884 Moles of MgO from 0.99 g O2 = 0.0619 Limiting ...
Monday, March 28, 2016 by Ben

Chemistry
C + HNO3 = CO2 + NO2 + H2O oxidation, reduction and balancing
Monday, March 28, 2016 by KORINA

Chemistry
If 12.01 g of Mg metal and 6.56 g of O2 gas are reacted, 1) How many moles of MgO can be produced from the given mass of Mg? 2) How many moles of MgO can be produced from the given mass of O2? 3) From the above calculations, determine which of the reactants is the limiting ...
Monday, March 28, 2016 by Ben

Chemistry
What is the complete ionic equation for the following reaction? Aqueous iron(III) sulfate is added to aqueous sodium sulfide to produce solid iron(III) sulfide and aqueous sodium sulfate.
Monday, March 28, 2016 by Sarah

Chemistry
A gas is bubbled through water at a temperature of 30°C and at an atmospheric pressure of 100.2 kPa. What is the pressure of the dry gas?
Monday, March 28, 2016 by jinal

Chemistry
Calculate the solubility (in grams per 1.00×10^2 mL of solution) of magnesium hydroxide in pure water.
Monday, March 28, 2016 by Salma

Chemistry
How does the solubility of Mg(OH)2 in a buffered solution compare to the solubility of Mg(OH)2 in pure water?
Monday, March 28, 2016 by Salma

Chemistry
The network parameter of molybdenum 0.314 Valley nm and its density to 20° C 10.22 Valley g/cm3. Determine the crystalline structure of the molybdenum
Monday, March 28, 2016 by Elizabeth

Chemistry
To prepare one liter of 2.5 M solution of HCl, what is the volume of concentrated HCl (37% p/p, d = 1.19 g/mL) to be used?
Monday, March 28, 2016 by Nadia

Chemistry
If 12.01 g of Mg metal and 6.56 g of O2 gas are reacted, 1) How many moles of MgO can be produced from the given mass of Mg? 2) How many moles of MgO can be produced from the given mass of O2? 3) From the above calculations, determine which of the reactants is the limiting ...
Monday, March 28, 2016 by Ben

Chemistry
what mass of NaCl do you need to make a 500mL of a 0.10M solution?
Monday, March 28, 2016 by LUIS

Chemistry
We're doing a spontentaity lab in chemistry and I wanted to make sure I was using the right equation to do the questions! Could someone make sure this is right?? q system = - (q water - q calorimeter)
Monday, March 28, 2016 by Alice

Chemistry
1)Naturally occuring boron is made up of 20% by mass of 10B isotope and 80% by mass of 11B isotope.Calculate the relative atomic mass of boron. (2)Natural Silicon containing ores contains 92% of 28Si, 5% of 29Si and 3% of 30Si.Calculate the relative atomic mass of Silicon.
Monday, March 28, 2016 by PEACE

chemistry
acetic acid and oxalic acid exist in different states at room temperature. one is a liquid the other is a solid which is the solid? Explain.
Monday, March 28, 2016 by Mia

Chemistry
Which of the following solutions has a molarity different from the rest? a. 6 N H3PO4 b. 4 N Ca(OH)2 c. 8 N HC2H3O2 d. 2 N NH40H
Monday, March 28, 2016 by Peabody

Chemistry
I BADLY NEEDED HELP ON THIS :( A volume of 1.1 liters of 02 was collected inside a balloon at 295 K and 13.6 psi. The next day, the surrounding conditions were observed to be 32 C and 0.98 atm. What is the volume of the gas inside the balloon? (1 atm = 14.7 psi) A. 0.107 liter...
Monday, March 28, 2016 by woody

Chemistry
Given that you are starting with 20.816 grams of Fe and 7.079 grams of O2, what is the THEORETICAL YIELD of Fe2O3 in moles?
Monday, March 28, 2016 by Ben

Chemistry
Given the reaction 2HI (aq) + CaCO3(s) = CaI2(aq)+CO2(g)+H2O(l) What volume of of CO2 can be produced from 255mL of 3.0M HI and 75.2g of CaCO3 at STP? 75.2g CaCO3/100.09g/mol CaCO3 =.751mol CaCO3 (3M)(.255L)=.765 mol HI
Monday, March 28, 2016 by Kevin

Chemistry
In a 1.0× 10–2 M solution of CH3NH3Br(aq), identify the relative molar amounts of these species. H2O, OH-, CH3NH3+, CH3NH2, H3O+, Br-, HBr
Monday, March 28, 2016 by Joe

Chemistry Honors
A sample of water has a temperature of 87.5 d/C. The volume of the sample is 430 mL. What mass of ice at 0.0 d/C will melt with this sample of water if the final temperature of water and melted ice is 0.0 d/?
Sunday, March 27, 2016 by Sim

Chemistry
Enough concentrated sulfuric acid solution was added to provide 3 grams of sulfuric acid which dissolved i4 grams of pure fluorapatite. How much excess sulfuric acid was used? (report answer in grams of H2SO4
Sunday, March 27, 2016 by Mae

Chemistry
Phosphorus fertilizers are derived from phosphate rocks, called florapatite, Ca5(PO4)3F. Fluorapatite is insoluble in water, so it must first be dissolved using excess sulfuric acid to form water soluble calcium dihydrogen phosphate Ca(H2PO4)2. If a posdered 5 gram sample of a...
Sunday, March 27, 2016 by Mae

Chemistry
Explain the relationship between the various properties of gases including pressure, temperature, volume, amount of gas, molar mass, and particle speed.
Sunday, March 27, 2016 by BB

Chemistry
Compare the diffusion rates of hydrogen and oxygen gases.
Sunday, March 27, 2016 by BB

Chemistry
A sample of gas is collected by water displacement. The atmospheric pressure in the room is 757mmHg and the vapor pressure of water is 17.5mmHg. What is the partial pressure of hydrogen under these conditions?
Sunday, March 27, 2016 by BB

Chemistry
A sample of gas at 57C and 1.02atm occupies a volume of 2.20L. What volume would this gas occupy at 107C and 0.789atm?
Sunday, March 27, 2016 by BB

Chemistry
A sample of gas at 57oC and 1.02atm occupies a volume of 2.20L. What volume would this gas occupy at 107oC and 0.789atm?
Sunday, March 27, 2016 by BB

chemistry
Calculate the pH after addition of 16.36 mL of 0.1349 M HBr to 25.00 mL of 0.1444 M NH3. Kb(NH3) = 1.800e-5. Answer: 9.059 PLEASE SHOW STEPS!
Sunday, March 27, 2016 by john

chemistry
Find the quantity of heat produced when 100ml of 0.1N HCL is completely neutralised with NAOH solution
Sunday, March 27, 2016 by chinmay

Chemistry
A student needs 0.14 mol of sodium sulphate to do an analysis. the concentration of the available solution is 2.6 m/L. What volume of the solution should the student measure out? What I've tried: C=N/V V=C/N V=2.6/0.14 V=18.6 The answer in the textbook says 54 mL...
Sunday, March 27, 2016 by AlphaPrimes

Chemistry
Describe how ametallic bond is d/t from those of an ionic bond and a covalent bond.
Sunday, March 27, 2016 by Yaekob

Chemistry
how many milliliters of a 5.0 m surcrose solution would be needed to prepare 45 mL of a 4.0 M solution?
Sunday, March 27, 2016 by Addy

Chemistry
0.573 g of calcium chloride reacts with excess of 0.5 M Na3PO4 to form .523 g of isolated calcium phosphate precipitate. Determine theoretical yield, actual yield, and percent yield for this reaction.
Saturday, March 26, 2016 by Kiana

Chemistry
Under certain conditions, nitrogen gas reacts with oxygen gas to form nitrogen monoxide gas. How many total electrons are transferred for each molecule of nitrogen or oxygen?
Saturday, March 26, 2016 by Kiana

Chemistry
Calculate the empirical formula of Tylenol: C, 63.56%; H, 6.00%; N, 9.27%; O, 21.17%
Saturday, March 26, 2016 by Jamie

Algebra
Two High Schools ordered AP Chemistry text book from the same book store. A New Hampshire school has ordered 80 copies, while a Vermont school ordered only 55 copies. The store has 70 books in its warehouses in Massachusetts and 100 books in the other warehouse in New York. ...
Saturday, March 26, 2016 by Anish Panda

Chemistry
What is the pH of a solution obtained by adding 15 g deK2SO4em 150 ml NaHSO4 with Molarity of 0, 2 m. HSO4 Ka = 1, 3.10^-2
Saturday, March 26, 2016 by Arya

Chemistry
What is the salt most likely to be formed at the junction of the Fe2+ions and SiO4+
Saturday, March 26, 2016 by Eliza

Chemistry
Balance the following redox reaction occurring in an acidic solution: ClO4^-+Br2=Cl^-+BrO3^- I get the two half reactions balanced as: 6e^-+(8H^+)+ClO4^-=Cl^-+4H2O and 6H2O+Br2=2BrO3^-+(12H^+)+10e^- Then I multiply the top equation by 5 and the bottom equation by 3. The e^- ...
Saturday, March 26, 2016 by Carol

chemistry
Explain using dilution formula how to prepare 0.2M hcl acid from 37% concentrated hcl acid
Saturday, March 26, 2016 by precious

Chemistry
At a certain temperature, the reaction has Kc = 5 x 108. If a reaction mixture at equilibrium contains 0.26 M of H2 and 0.087 M of Cl2, what is the concentration of HCl?
Saturday, March 26, 2016 by Anonymous

Chemistry
At a certain temperature, the reaction has Kc = 5 x 108. If a reaction mixture at equilibrium contains 0.26 M of H2 and 0.087 M of Cl2, what is the concentration of HCl?
Saturday, March 26, 2016 by Em

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Homework Help: Science