Sunday
December 21, 2014

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

Post a New Question | Current Questions

chemistry
why do we use the limiting reactant data to calculate delta h? why might it be important to know delta h prior to running a reaction?
Thursday, November 13, 2014 at 3:39am

Chemistry
0.100 moles of NaOH are combined with 0.125 moles acetic acid. The mixture is taken to a final volume of 100.00 ml. What is the expected pH of the solution? Use Ka for acetic acid of 1.76 x 10^-5
Thursday, November 13, 2014 at 12:40am

Chemistry
20.0 ml of 1.00 M formic acid are combined with 10.0 ml of 1.00 M sodium formate. Calculate the expected pH. Ka for formic acid is 1.77 x 10^-4
Thursday, November 13, 2014 at 12:37am

Chemistry (Equilibrium)
Consider the following equilibrium system at 900°C: H20(g) + CO(g) <==> H2(g) + CO2(g) Initially 5.0 moles of H2O and 4.0 moles of CO were reacted. At equilibrium, it is found that 2.0 moles of H2 are present. How many moles of H2O remain in the mixture? Would be ...
Wednesday, November 12, 2014 at 9:15pm

chemistry
Which sample has the most solute? Question 15 options: 200. mL of 0.200 M MgCl2 150. mL of 0.250 M MgCl2 100. mL of 0.300 M MgCl2 100. mL of 0.250 M MgCl2
Wednesday, November 12, 2014 at 7:49pm

chemistry
{V1} mL of 0.100 M HCl is placed in a {V2}.0 mL volumetric flask and water is added to bring the final volume up to 250.0 mL. What is the molarity of the dilute solution?
Wednesday, November 12, 2014 at 7:48pm

chemistry
How much CaCl2 (MM = 111.0 g/mol) would you weigh out to prepare 325. mL of 0.150. M CaCl2?
Wednesday, November 12, 2014 at 7:48pm

chemistry
23.9 g of CaCl2 (MM = 111.0 g/mol) is dissolved in enough water to make 300. mL of solution. What is the molarity of the solution?
Wednesday, November 12, 2014 at 7:47pm

Chemistry 11
Find the percent composition of a compound containing sodium and chlorine if 24.34g of the compound contains 13.45g of sodium. My work: Molar mass of NaCl: MNa +MCl = 22.99 g/mol + 35.45 g/mol = 58.44 g/mol Percent composition of Na: 22.99 g/mol / 58.44 g/mol x 100 = 39.34% Na...
Wednesday, November 12, 2014 at 7:17pm

chemistry
The reaction SO2 + H2O =H2SO4 Is the last step in the commercial production of sulfuric acid . the enthalpy change for this reaction is -227 KJ . In designing a sulfuric acid plant is it necessary to provide for heating or cooling of the reaction mixture ? explain
Wednesday, November 12, 2014 at 6:35pm

Chemistry
Consider the following equilibrium: 2HI(g) *are in equilibrium with* H2(g) = I2(g) Keq = 81.0 A 2.00L container is initially filled with 4.00 mol HI. Calculate the [HI] at equilibrium. *I don't know how to put the equilibrium sign on the computer* Can someone please ...
Wednesday, November 12, 2014 at 6:35pm

Chemistry
What is the molar mass of 0.500 g of unknown monoprotic acid used in titration, if 22.5 mL of 0.15 M NaOH solution was required to neutralize it? I do not need the answer, but instead an example of how to do a question just like it.
Wednesday, November 12, 2014 at 5:11pm

Chemistry
1. what type of covalent bonded liquid will a polar covalent solid dissolve in? (hint like dissolves like) 2. what type of covalent bonded liquid will a non polar covalent solid dissolve in? (hint like dissolves like) 3. In what type of solvent will a polar solute dissolve? In...
Wednesday, November 12, 2014 at 5:06pm

Chemistry
0.05 L of chlorine gas is bubbled through 0.5 L of 2 M sodium Bromide solution. -What type of reaction is this ? A) Single Replacment B) Double Replacement C) Synthesis D) Decomposition E) Combustion - What product(s) will be predicted for this reaction? (bubble all that apply...
Wednesday, November 12, 2014 at 4:49pm

chemistry
2.9 in3 of mercury to its volume in milliliters and its mass in kilograms
Wednesday, November 12, 2014 at 4:41pm

chemistry
calculate the amount of heat released when 77.0g of steam at 104.5 celsius cools to ice at 0.0 celsius. I don't understand the steps to take to solve this problem. Can someone walk me through it please?
Wednesday, November 12, 2014 at 4:32pm

chemistry
263 mL ethanol to its mass in grams
Wednesday, November 12, 2014 at 4:29pm

Chemistry
Iron has density 7.87 g/cm3. If 52.3 g of iron is added to 74.5 mL of water in a graduated cylinder, to what volume reading will the water level in the cylinder rise? mL
Wednesday, November 12, 2014 at 4:02pm

chemistry
a student measures the conductivity of a KNO3 solution and determines it to be a strong electrolyte.what species are in solution?
Wednesday, November 12, 2014 at 3:23pm

chemistry
28.09 g of silicon contains 6.02 1023 silicon atoms. What is the mass in grams of 1.06 1025 silicon atoms? Can you help me please.
Wednesday, November 12, 2014 at 3:06pm

Chemistry
28.09 g of silicon contains 6.02 1023 silicon atoms. What is the mass in grams of 1.06 1025 silicon atoms?
Wednesday, November 12, 2014 at 2:03pm

Chemistry
if 10.0L of neon gas exerts a pressure of 125psi at 373K, what is the number of moles of gas? I don't know how to set this up. I am using ideal gas law N=PV/RT but my answer is not matching. I converted the 125psi to 8.50atm N= 8.50atm*10.0L/1 k * 373k*1 mol/1 atm * 0.0821...
Wednesday, November 12, 2014 at 12:38pm

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...
Wednesday, November 12, 2014 at 4:53am

chemistry
Write the chemical equation to represent what happens when a small piece of pottasium is dropped in a beaker of water.
Wednesday, November 12, 2014 at 1:38am

chemistry
What is the chemical eguation for a small piece of pottasium dropped In a beaker of water.
Wednesday, November 12, 2014 at 1:25am

Chemistry
Write the formula for a complex formed between Zn2 and OH–, with a coordination number of 4.
Tuesday, November 11, 2014 at 11:51pm

Chemistry
For each metal complex, give the coordination number for the metal species. Na[Ag(CN)2 [Cd(en)Br2
Tuesday, November 11, 2014 at 11:50pm

Chemistry
What is the temperature of 0.65mol {\rm mol} of gas at a pressure of 1.5atm {\rm atm} and a volume of 12.6L {\rm L} ?
Tuesday, November 11, 2014 at 9:57pm

chemistry
the frequency factor and activation energy for a chemical reaction ate A=4.8 x 10^-12cm^3 and Ea=11.1kJ/mol at 327 K respectively. Determine the rate constant for this reaction at 327K
Tuesday, November 11, 2014 at 8:23pm

chemistry
How many grams of Pb(IO3)2(s) are precipitated when 27.0 mL of 3.00 M Pb(NO3)2(aq) are mixed with 30.0 mL of a 5.00 M KIO3(aq) solution? 3.00M(.o27)(1mol Pb(IO3)2)/1mol Pb(NO3)2)(557/1)
Tuesday, November 11, 2014 at 8:19pm

Chemistry
How do you balance, step by step C2H5OH + K2Cr2O7 + H2SO4 = Cr2(SO4)3 + K2SO4 + CH3COOH + H2O?
Tuesday, November 11, 2014 at 5:53pm

Chemistry
step by step, show how to balance C2H5OH + K2Cr2O7 + H2SO4 = Cr2(SO4)3 + K2SO4 + CH3COOH + H2O
Tuesday, November 11, 2014 at 5:48pm

chemistry
The vapor pressure of liquid chloroform, CHCl3, is 100. mm Hg at 283 K. A 0.198 g sample of liquid CHCl3 is placed in a closed, evacuated 400. mL container at a temperature of 283 K. Assuming that the temperature remains constant, will all of the liquid evaporate? What will ...
Tuesday, November 11, 2014 at 5:39pm

chemistry
What mass of the metal must be heated to 95 degrees celsius in order to be used to warm 2.548 L of water from 18.1 to 22.5 celsius
Tuesday, November 11, 2014 at 5:02pm

chemistry
what are clones a. an exact copy of an organism b. a sheep named dolly c. d. all of the above what can i put for the other that are not the answers, i don't like b,d what can i put the answer is a
Tuesday, November 11, 2014 at 4:37pm

chemistry
The issue of cloning has been an issue for quite some time. Many believe that cloning is unethical, The biggest reason is because they believe it's unethical to act “like God by creating an embryo that develops into a human being?” However they also believe that ...
Tuesday, November 11, 2014 at 3:28pm

chemistry
what are clones a. an exact copy of an organism b. a sheep named dolly c. d. all of the above what can i put for the other that are not the answers, i don't like b,d what can i put the answer is a
Tuesday, November 11, 2014 at 3:19pm

Chemistry
The end point of the acid base/ titration between vinegar and NaOH occurred when: Question options: The acid and base neutralized each other. The phenolphthalein indicator turned faint pink. The moles of H+ were equal to the moles OH- All of the above
Tuesday, November 11, 2014 at 3:08pm

Chemistry
The equilibrium constant, Keq, is defined as the ratio of the concentrations of products to reactants. What is the equilibrium constant for the following reaction: ClNO2 (g) + NO (g) ↔ NO2 (g) + ClNO (g)
Tuesday, November 11, 2014 at 3:01pm

Chemistry
Calculate the value of the equilibrium constant for the following reaction based on the given concentrations of reactants and products. N2 = 1.5 M, H2 = 0.5 M, NH3 = 2 M N2 (g) + H2 (g) ↔ NH3 (g)
Tuesday, November 11, 2014 at 3:01pm

Chemistry
The specific heat capacity of a metal is given as 0.745 J/ degree Celcius.What mass of the metal must be heated to 95 degree Celcius in order to be used to warm 2.548 L of water from 18.1 degree Celcius to 22.5 degree Celcius ? I'm so confused I don't even know where ...
Tuesday, November 11, 2014 at 2:45pm

Chemistry
What is the significance of a potential energy diagram? What kind of global picture does it provide about the reaction?
Tuesday, November 11, 2014 at 1:10am

Science-Chemistry
What is ΔH° for vaporizing liquid water at 25°C? What is ΔS° for vaporizing liquid water at 25°C? What is ΔG° for vaporizing liquid water at 25°C?
Tuesday, November 11, 2014 at 1:01am

chemistry
a solution consisting of 1.6M NaNO3 and 1.0M of Na(NO3)2 please help
Monday, November 10, 2014 at 10:58pm

Chemistry
What is the molarity of 35.0 of NaCl in 125 mL of water?
Monday, November 10, 2014 at 9:31pm

Chemistry
How many moles of LiF would be required to produce a 12.0 M solution with a volume of 10.5 L?
Monday, November 10, 2014 at 9:03pm

Intro to Chemistry
When calcium carbonate is added to hydrochloric acid, calcium chloride, carbon dioxide, and water are produced. CaCO3(s)+2HCl(aq)=CaCl2(aq)+H2O(l)+CO2(g​) How many grams of calcium chloride will be produced when 27.0 g of calcium carbonate are combined with 11.0 g of ...
Monday, November 10, 2014 at 8:49pm

Intro to Chemistry
Given the following chemical equation, determine how many grams of N2 are produced by 8.58 g of H2O2 and 5.62 g of N2H4. 2H2O2(l)+N2H4(l)=4H2O(g)+N2(g)
Monday, November 10, 2014 at 8:44pm

chemistry
In the molecular weight determination experiment, what would be the effect if some air remains in the flask after the compound was completely vaporized?
Monday, November 10, 2014 at 7:43pm

Chemistry
If a balloon containing 1000 L of gas at 50 degrees Celsius and 101.3 kPa rises to an altitude where the pressure is 27.5 kPa and the temperature is 10 degrees Celsius, its volume there is?
Monday, November 10, 2014 at 6:33pm

chemistry
How many milliliters of 5.50 M HCl must be diluted to make 350. mL of a 0.500 M solution?
Monday, November 10, 2014 at 5:34pm

chemistry
What mass of KCl (MM = 74.55 g/mol) is required to make 750 mL of a 0.275 M solution?
Monday, November 10, 2014 at 5:34pm

chemistry
The acceptable limit for nitrate, often found in well water in agricultural areas, is 10 ppm. If a water sample is found to contain 355 µg/L, determine the concentration in parts per million, ppm. Express your answer in decimal form rounded to the third decimal place. Do...
Monday, November 10, 2014 at 5:33pm

chemistry
Calculate the quantity of heat in calories absorbed when 131.01 g of water is heated from 21.1°C to 50.4°C. Enter your answer as a whole number (no decimal portion). Do not include units with your answer.
Monday, November 10, 2014 at 5:33pm

chemistry
How many milliliters of 4.50 M HCl must be diluted to make 400. mL of a 0.500 M solution?
Monday, November 10, 2014 at 3:32pm

chemistry
What mass of KCl (MM = 74.55 g/mol) is required to make 550 mL of a 0.250 M solution?
Monday, November 10, 2014 at 3:32pm

chemistry
how many moles of HCL are contained in 34.7 mL of 8.00 M solution ?
Monday, November 10, 2014 at 3:32pm

Chemistry
What would cause the molecules of gas to get closer together?
Monday, November 10, 2014 at 2:27pm

Chemistry
Consider the evaporation of water at 298 K and 1 atm pressure: H20 (l) <---> H20 (g) Given that ΔGOrxn= 8.6kJ/mol, what is the equillibrium vapor pressure of water at 298 K?
Monday, November 10, 2014 at 1:37pm

Chemistry
What is the approximate ΔH in kJ for the following reaction as written: 2NH3(g) --> 3H2(g) + N2(g) Careful, what kind of bond does the nitrogen molecule make?
Monday, November 10, 2014 at 9:46am

Chemistry
Arrange the following diatomic molecules in order of weakest to strongest bond: HF, HCl, HBr, and HI.
Monday, November 10, 2014 at 9:46am

Chemistry
Which of the following ionic compounds has the highest melting point? Help: Lattice energy Select one: a. Cs2O b. K2O c. BeO d. SrO e. LiF f. CsI
Monday, November 10, 2014 at 9:44am

chemistry
how many grams of CO are needed to react with 2.90 grams of Fe2O3?
Sunday, November 9, 2014 at 11:52pm

Chemistry 2
what is the pH in a 0.13M solution of aniline (Kb=4.3*10^-10). What is the concentration of C6HNH2 in the same solution?
Sunday, November 9, 2014 at 11:02pm

chemistry
Consider the reaction between 52.0 mL of liquid ethanol (C2H5OH; density = 0.789 g/mL) and 25.4 L of O2 at 27.0°C and a pressure of 1.65 atm. The products of the reaction are CO2(g) and H2O(g). Calculate the number of moles of H2O formed if the reaction goes to completion.
Sunday, November 9, 2014 at 9:40pm

chemistry
If 8.16 g of CuNO3 is dissolved in water to make a 0.500 M solution, what is the volume of the solution?
Sunday, November 9, 2014 at 8:56pm

Chemistry
Describe what happens to a co2 sample when the following changes are made: (a) The temperature is increased from -100°c to 0°c at constant pressure of 2 atm B) The pressure is reduced from 72 atm to 5.0 atm at a constant temperature of 30°c C) The pressure is first...
Sunday, November 9, 2014 at 7:20pm

chemistry
How do you write a balanced equation for the preparation of phenylmagnesium bromide and it's reaction with benzophenone followed by neutralization in acid?
Sunday, November 9, 2014 at 6:29pm

Chemistry
Using the following data 1. CU3+ + 2e- ---> Cu+ E1= 1.28V 2. CU2+ + e- ---> Cu+ E2= 0.15V 3. Cu2+ + 2e- ----> Cu(s) E3= 0.34V 3. Cu+ + e- ----> Cu (s) E4= 0.52V calculate the standard reduction potential for the reaction of Cu(III) to Cu(II). Is it .783 V?
Sunday, November 9, 2014 at 4:39pm

Chemistry
If there are 25 mg of water in a typical drop of water, how many drops of water would react completely with 2 mmol of phenylmagnesium bromide? How do I set up the problem?
Sunday, November 9, 2014 at 4:30pm

Chemistry
Is my answer correct? Calculate the mass of frost (water ice) on a piece of dry ice that would completely react with 2 mmol of phenylmagnesium bromide. (1/44 CO2)*(0.002mol of phenylmagnesium bromide)= 0.0000455
Sunday, November 9, 2014 at 4:28pm

Chemistry
What isthe theoretical yield of a microscale reaction of these materials in which 300 mg of bromobenzene, 50 mg of magnesium, and 350 mg of benzophenone were used?
Sunday, November 9, 2014 at 4:23pm

chemistry
What is the vapor pressure of a solution of 0.5mol of a non-volatile impurity x and 2.0 g of TaCl5 (L) at a temperature of 226 degrees celcius? The vapor pressure of TaCl5 (l) at 226 degrees celcius ,621mmHg
Sunday, November 9, 2014 at 1:49pm

chemistry
Calculate the molar mass of TaCl5 (g). when 8.95 (g) are present and occupy a volume of 715ml at a temperature of 250 degrees celcious and 1.5 atm pressure.
Sunday, November 9, 2014 at 1:45pm

Chemistry
2.The solubility of sodium chloride at 20 degrees Celsius is 358g/1000g H20, or 358g/1358g solution. How many grams of sodium chloride would you expect to dissolve in 2200 grams of H20 at 20 degrees Celsius?
Sunday, November 9, 2014 at 12:25pm

chemistry
The equilibrium constant for the chemical equation is K = 4.90 at 199 °C. Calculate the value of the Kc for the reaction at 199 °C. N2(g)+3H2(g)=2NH3(g) Kc=?????
Sunday, November 9, 2014 at 11:47am

chemistry
1. (3.0x10^4) divided by (6.2x10^1) = 5x10^2? 2. (4.7x10^-3) divided by (9x10^-4) = 5x10^-6 3. (3.0x10^4) times (6.2x10^1) =1.9x10^6 4. (4.7x10^-3) divided by (9x10^-4) =5x10^-6 5. (5.1x10^2) divided by (3x10^4)
Sunday, November 9, 2014 at 10:27am

Clinical chemistry
Prepare a 10 percent solution of sulphuric acid from a 98 percent stock solution of the acid in a 500mls beaker
Sunday, November 9, 2014 at 6:32am

Chemistry
Using the following data 1. CU3+ + 2e- ---> Cu+ E1= 1.28V 2. CU2+ + e- ---> Cu+ E2= 0.15V 3. Cu2+ + 2e- ----> Cu(s) E3= 0.34V 3. Cu+ + e- ----> Cu (s) E4= 0.52V calculate the standard reduction potential for the reaction of Cu(III) to Cu(II). Is it .783 V?
Sunday, November 9, 2014 at 4:36am

Clinical chemistry
Describe how you can prepare 0.25 molar solution of sodium hydroxide from an 80 percent stock solution in a 500mls beaker
Sunday, November 9, 2014 at 1:30am

Chemistry
If 500 mol of hydrogen gas occupies 5.00L at 25 celsius, what is the pressure in atm? I believe this is Ideal gas law. I can't figure out how to put it in the PV=nRT.
Sunday, November 9, 2014 at 12:48am

chemistry
Is it appropriate to call a soft drink an aqueous solution? Justify your answer.
Saturday, November 8, 2014 at 9:57pm

Chemistry
I'm having trouble understanding Boyle's Law and Dalton's law of partial pressures. Can anyone help me work this please? Thank you A sample of propane gas, C3H8, was collected over water at 22.5 ºC and 680. torr. The volume of the wet gas is 3.89 L. What will ...
Saturday, November 8, 2014 at 9:05pm

Chemistry
What is the density (in mg/mL) of a H2S gas at 12.9 atm and 137 K?
Saturday, November 8, 2014 at 9:00pm

Chemistry
What is the molar mass of a gas (96.0 g) in a 25.0 L container at 27.0 °C? The pressure inside the container is 3.04E5 Pa.
Saturday, November 8, 2014 at 8:18pm

Chemistry
what are the simplest molecules to synthesize a n,n-dimethyl-2-methylpropanamine
Saturday, November 8, 2014 at 6:28pm

chemistry
3. If 5.20 g of HCl is added to enough distilled water to form 3.00 L of solution, what is the molarity of the solution? [Use molecular weight: HCl, 36.46 amu] 5.20/36.46= 0.1426 X 3.00=0.428 M IS THIS CORRECT
Saturday, November 8, 2014 at 4:04pm

Chemistry
What would be the molarity of a solution made by dissolving 126g K3PO4 into 1500 mL of water?
Saturday, November 8, 2014 at 3:02pm

Science: Chemistry
1. The element gold, Au, has a face-centered cubic structure. (Density - 19.3 g/cm^3) (a) What are the # of gold atoms in 1 unit cell? (b) What are the # of unit cells in 1 mol? (c) What is the volume of 1 mol gold unit cells? (d) What is the volume of 1 unit cell? (e) what is...
Saturday, November 8, 2014 at 2:39pm

chemistry
(3.0 x 10^4 ) ÷ (6.2 x 10^1) = 18.6x10^3 (4.7 x 10^-3 ) ÷ (9 x 10^-4) = 42.3x10^-7 (3.0 x 10^4 ) x (6.2 x 10^1) = 18.6x10^3 (5.1 x 10^2 ) x (3 x 10^4) = 15.3x10^-2
Saturday, November 8, 2014 at 2:15pm

Chemistry
1. The eleent gold, Au, has a face-centered cubic structure. (Density - 19.3 g/cm^3) (a) What are the # of gold atoms in 1 unit cell? (b) What are the # of unit cells in 1 mol? (c) What is the volume of 1 mol gold unit cells? (d) What is the volume of 1 unit cell? (e) what is ...
Saturday, November 8, 2014 at 2:05pm

Chemistry
What is the molarity of a solution made by mixing 213.6 ml of 1.5 M NaCl with 328 ml of 4.3 M NaCl?
Saturday, November 8, 2014 at 1:50pm

Chemistry
How many hydrogen bonds can each (i) water and (ii) ice molecule form?
Saturday, November 8, 2014 at 11:11am

Chemistry
A salt may be prepared by the reaction of one salt with another salt, particularly if one of the products is insoluble. In which one of the following reactions is this demonstrated? (NH4)2CO3 + K2SO4 \->(NH4)2SO4 + K2CO3 CuCl2 + 2 NH4NO3 \-> Cu(NO3)2 + 2 NH4Cl Sr(NO3)2...
Friday, November 7, 2014 at 11:55pm

Organic Chemistry
I have a Lab assignment that requires the synthesis of carboxylic acid and our final product is Benzoic Acid. The following equation was provided: C7H8 + KMnO4 ---> MnO2 1) KMnO4, OH-, heat 2) H3O+ We were asked to balance the equation including the by-products. I was able ...
Friday, November 7, 2014 at 11:55pm

Chemistry
Calculate the mass (in grams) of sugar, C12H22O11, in 142.4 mL of a 1.39 M solution of sugar. (atomic weights: C = 12.01, H = 1.008, O = 16.00)
Friday, November 7, 2014 at 11:51pm

Chemistry
What mass (in grams) of sodium chloride, NaCl, is needed to make 422. g of a 3.39%(m/m) NaCl solution? (atomic masses: Na = 22.99, Cl = 35.45)
Friday, November 7, 2014 at 11:51pm

Chemistry
A salt may be prepared by the reaction of one salt with another salt, particularly if one of the products is insoluble. In which one of the following reactions is this demonstrated? (NH4)2CO3 + K2SO4 \(->NH4)2SO4 + K2CO3 CuCl2 + 2 NH4NO3 \->Cu(NO3)2 + 2 NH4Cl Sr(NO3)2 + ...
Friday, November 7, 2014 at 11:29pm

Chemistry
what are the simplest molecules to synthesize a n,n-dimethyl-2-methylpropanamine
Friday, November 7, 2014 at 10:48pm

chemistry
8.00g of NaOH are dissolved in water to make 4.00L of solution. What is the concentration of hydronium ions, [H3O+], in this solution? Express your answer with the appropriate units.
Friday, November 7, 2014 at 10:32pm

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