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Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

Chemistry
Aluminum and oxygen react to form aluminum oxide. 4 Al + 3 O2 2 Al2O3 a. What is the limiting reactant if 30.7 g Al are reacted with 38.3 g of O2? b. What is the theoretical yield of Al2O3, in grams? c. If 35.3 g of Al2O3 are obtained, what is the percent yield?

Chemistry
Consider the following reaction. 2KClO3(s) → 2KCl(s) + 3O2(g) a.) How many grams of KCl are produced from the complete reaction of 12.5 mol of KClO3? b.) How many grams of KCl are produced from the complete reaction of 38.4 g of KClO3? Please explain how to solve for the ...

Chemistry
When nitrogen dioxide is bubbled through a solution of potassium permanganate, the solution turns colorless. Which of the following statements is true? Question 3 options: 1) The test reveals that nitrogen dioxide is a colored gas. 2) The test reveals that nitrogen dioxide is ...

chemistry
An aqueous solution containing bromothymol blue is used to identify the chemical properties of thionyl chloride gas. When the gas is bubbled through the bromothymol blue solution color changes from blue to yellow we could say that the gas ____________________. Question 4 ...

Chemistry
The sodium sulfite-acid solution should be disposed of by ____________________. Answers Options: 1) washing down the drain with large amounts of water. 2) washing out with diluted sodium bicarbonate for sink disposal. 3) neutralizing the solution with sodium bicarbonate before...

math
In a class of 80 students,53 study Art,60 study biology,36 study art and biology,34 study art and chemistry,6 study biology and 18 study biology but not chemistry.Determine the number of students who study =Art only =Chemistry only

Chemistry
Consider a one step reaction. Which of the following does not describe the activation energy of the process? The minimum amount of energy needed for a reaction to occur The energy difference between the starting point and the transition state The energy required to distort or ...

Chemistry
Assuming that the unknown acid sample in question 1 had a mass of 0.177 g, what is the molar mass of the unknown acid?

Chemistry
Suppose that 16.41 mL of 0.0512 M NaOH were required to titrate a sample of unknown acid. How many moles of NaOH were used?

Chemistry
We will calculate the amount of acid to use in each titration. Assume that you are using 0.0512 M NaOH(aq). A good volume of NaOH(aq) to use per titration is 15 mL. From this molarity and volume, the moles of NaOH can be calculated. Since the unknown acid is monoprotic, this ...

Maths
In a class of 80 students,53 study Art,60 study biology,36 study Art and biology,34 study Art and chemistry,6 study biology but not chemistry.Illustrate the information on a Venn diagram.Determine the number of students who study Art only And Chemistry only

Chemistry
Aluminum oxide contains 53% of Al. How much oxygen combines with 26.5g of aluminium to form aluminium oxide? Thank you

Chemistry
Benzene (C6H6) has a normal freezing point of 5.50oC and a density of 0.88 g/mL. When 1.28 g of naphthalene (C10H8) is dissolved in 125 mL of benzene, the freezing point of the solution is 5.03oC. Determine the molal freezing point constant for this solvent.

Chemistry
Consider a one step reaction. Which of the following does not describe the activation energy of the process? The minimum amount of energy needed for a reaction to occur The energy difference between the starting point and the transition state The energy required to distort or ...

Chemistry
A 17.7kg piece of zinc at 73 degrees celsius is placed in a container of water. The water has a mass of 23 kg and has a temperature of 13.4 degrees celsius before the zinc is added. what is the final temperature of water?

Chemistry
What are at least 2' real world uses of colligative properties?

Chemistry
1. Calculate the MOLALITY (m=mol/kg) of the salt water solution. Note: Include the mass of ice AND volume of water when calculating the TOTAL MASS of the solvent (water). (1ml of water=1g of water. Is my work correct? So what I did was, Knowing m=mol/kg for molality, the ...

Chemistry
What's the pH of 0.15M C3H6O3?

Chemistry
For the reaction CS2+3Cl2=CCl4+S2Cl2, calculate the percent yield if 719 g of CCl4 are produced when 410 g of CS2 react w/ an excess of chlorine. I have absolutely no clue on how to do this!! If I could get some help that would be great!!

Chemistry 2
The solubility of CO2 in water is 3.2 x 10^2 M at 25 C and 1 atm pressure. What is the Henry's Law constant for CO2 in mol/(L atm)? c=kP 0.25= kP p=kc p/k=kc/k =Px 1/k Please help!

Chemistry
Hydrogen gas, H2, reacts with nitrogen gas, N2, to form ammonia gas, NH3, according to the equation 3H2(g)+N2(g)→2NH3(g) PArt 1: How many grams of NH3 can be produced from 3.26 mol of N2 and excess H2. Part 2: How many grams of H2 are needed to produce 13.17 g of NH3? part 3...

chemistry
1. based on the equation below, how many liters of water can be produced from 8.5 L (assume that hydrogen is in excess) 2H2(g)+O2(g) --->2H2O(g)

Chemistry
1.38 mol HCl and 2.9 mol NaOH react accord- ing to the equation HCl + NaOH −→ NaCl + H2O . If the limiting reactant is HCl, determine the amount of excess reactant that remains. Answer in units of mol.

Chemistry
How many representative particles are in 2.5 mol H2O2?

Chemistry Lab
Data and Calculations: 1. Volume of water in calorimeter: 100.0 mL 2. Mass of water in calorimeter (water's density 1.00g/mL): 100.0g 3. Initial Temperature of water in calorimeter:19.5 degrees Celsius 4. Final Temperature of water in calorimeter: 3.0 degrees Celsius 5. Final ...

Chemistry
1.38 mol HCl and 2.9 mol NaOH react accord- ing to the equation HCl + NaOH −→ NaCl + H2O . If the limiting reactant is HCl, determine the amount of excess reactant that remains. Answer in units of mol.

Chemistry
Will increasing the temperature of H20 before dissolving Ca(IO3)2 affect how much Ca(IO3)2 is dissolved? I think this has something to do temperature and Le Chatelier's Principle and equilibrium. So, would more be dissolved at a higher temperature than at a lower temperature ...

chemistry
You are given a 500 mL stock solution of 10%CaCl2 and are askes to prepare a 50 mL solution of .5% CaCl2. How would you prepare it? Please show work

Chemistry
A first order reaction ABC → AB + C has a rate constant of 0.0125 /s. If the initial concentration of ABC is 0.500 M, what is the concentration of ABC after 5 minutes? Note: do not include units in your answer, do not use scientific notation.

chemistry (ap)
What will be the reaction rate (formation of C) when the concentrations of A & B are 0.150 M and 0.250 M respectively?

CHEMISTRY
What will be the reaction rate (formation of C) when the concentrations of A & B are 0.150 M and 0.250 M respectively?

Chemistry
Calculate the pH of HCL if you have 10.0g in 5.0L of solution

chemistry
in the laboratory, concentrated hydrogen chloride acid reacted with aluminium. hydrogen gas evolved was collected over water at 25 degree celcius and had a volume of 355 centimetre cube at a total pressure of 750mmHg.(the vapour pressure of water at 25 degree celcius equal to ...

chemistry
Calculate the energy of a photon emitted when an electron in a hydrogen atom undergoes a transition from n=5 to n=1 in J.

chemistry
How I doing electrolysis of aluminium cloraed?

chemistry
Al2Br6, xpress your answer as a chemical formula?

Chemistry
At what speed must a human weighing 150.0 lb be traveling in order to have a wavelength at 650 nm?

Chemistry
Calculate the number of valence electrons in BF3.

Chemistry
Why was sublimation performed under reduced pressure?

Chemistry
Calculate the pH values and draw the titration curve for the titration of 500 mL of 0.010 M acetic acid (pKa 4.76) with 0.010 MKOH. Calculate the pH of the solution after 490 mL of the titrant have been added.

Chemistry
Calculate the new freezing point and the new boiling point of an aqueous solution that contains 40.5 g of Calcium Nitrate dissolved in 225 grams of water.

chemistry
Word equation of dissolving zinc in dilute susurphuric acid

Chemistry
A typical solid fertiliser for use with household plants and shrubs contains the elements N, P and K in the ratio of 15g: 30g: 15g per 100g of fertiliser. The recommended usage of fertiliser is 14g of fertiliser per 5dm^3 of water. What is the concentration of nitrogen atoms ...

Chemistry
Describe the procedure you would follow to determine the concentration of vitamin c in a sample if the volume of dcpip required to reach the end point were more than the 10-mL graduated cylinder could hold. The titration must still be carried out in the 10-mL graduated ...

chemistry
Which of the following statements is false ? a) S is negative when water condenses at 100oC b) Ssurroundings is positive when water condenses at 100oC c) Suniverse is equal to zero when water condenses at 990C d) Suniverse increases when water condenses at 110oC

Chemistry
A closed bottle contains a solution of 5.0% by mass acetone [(CH3)2CO] in water. Calculate the vapour pressure (in kPa) of this solution at 25oC. The vapour pressure of pure water at 25oC is 3.17 kPa and that of pure acetone is 30.7 kPa.

Chemistry
Fireflies flash at a rate that depends on the temperature. At 29oC, the average rate is 3.3 flashes every 10 seconds, whereas at 23oC, the average falls to 2.7 flashes every 10 seconds. Calculate the "energy of activation" (in kJ/mol) for the flashing process.

Chemistry
What type of solid is Ne? Metallic? Molecular? Ionic? or Covalent Network?

Chemistry
What will be the mass of ferrous sulphide formed when 20 gram of pure sulphur reacts with iron ?

Chemistry
How many grams of H2O are needed if 41.85g of O2 are to be produced from the reaction below? 2K2O2 + 2H2O = 4KOH + O2

chemistry
A dilution is made during the preparation of a reaction mixture. The compounds are: 2.00 ml of 0.325 KMnO4, 7.50 ml of 0.155 M Oxalic acid, and 10.00 ml of H2O. What are the final concentrations of the compounds?

Chemistry
PartA: What volume of 10.0M NaOH is needed to prepare a buffer with a pH of 7.79 using 31.52 g of TrisHCl? TrisHCl is a weak base and the molecular weight is 157.67 g/mol. I found the solution, it is 6.67 milliliters. Part B: "The buffer from Part A is diluted to 1.00 L. To ...

Chemistry
Consider a one step reaction. Which of the following does not describe the activation energy of the process? The minimum amount of energy needed for a reaction to occur The energy difference between the starting point and the transition state The energy difference between the ...

enviromental chemistry
If 10 ppm of nitrogen dioxide is present 1000 L of air at a pressure of 1 atm and temperature of 27 °C, what is the amount of ammonia necessary to react?

Chemistry
The common picnic ant walks with a velocity of 0.01 meters per second (m/s). How long will it take an ant to walk across a 8 ft long picnic table, assuming it does not meet with an untimely demise along the way? (1 m = 39 in, 1 ft = 12 in) 8ft/1 X 12in/1in X 2.54cm/1in

Chemistry
The photoelectric work function of a metal is the minimum energy needed to eject an electron by irradiating the metal with light. For calcium, this work function equals 4.34 x 10-19 J. If light with a wavelength of 256 nm impinges on a piece of calcium, what is the speed of ...

Chemistry
The photoelectric work function of a metal is the minimum energy needed to eject an electron by irradiating the metal with light. For calcium, this work function equals 4.34 x 10-19 J. If light with a wavelength of 256 nm impinges on a piece of calcium, what is the speed of ...

chemistry
In part B of my question, I was asked calculate the number of atoms in 0.462 mol of 13C (mass number of this Carbon is 13). I received the correct answer of 2.78E23 atoms. However, I do not know how to do Part C of my question, which asks "Based on your answer in Part B, how ...

Chemistry
How many grams of urea would have to be dissolved in 250 grams of water to give it a freezing point of -4.degrees celcius

chemistry
Calculate the pH values and draw the titration curve for the titration of 500 mL of 0.010 M acetic acid (pKa 4.76) with 0.010 MKOH. Calculate the pH of the solution after 490 mL of the titrant have been added. Calculate the pH of the solution after 500 mL of the titrant have ...

Chemistry
Magnesium has three stable isotopes: 24Mg, 25Mg, 26Mg. The relative abundance of 24Mg is 79%. What are the relative abundances of 25Mg and 26Mg?

CHEMISTRY
1. Not sure of how to do the calculations... Make a 0.200 m solution of NaCl in a 100. mL volumetric flask. ... Solution A's question or statement is the same but with M (molarity) Is this right? The small m means molality. If it were changed to capital M, then solution A's ...

Chemistry
If 0.35 moles of SO3 is placed in a 1 dm3 flask and allowed to come to equilibrium at a high temperature, 0.207 mole of S03 remains. Calculate Kc For the reaction 2SO3 Double arrow 2SO2 +02

Chemistry
its takes 145 mL of zinc nitrate to react completely with 175 ml of 1.5 M potassium hydroxide. what is the concentration if zinc nitrate?

Chemistry
1. Not sure of how to do the calculations... Make a 0.200 m solution of NaCl in a 100. mL volumetric flask. ... Solution A's question or statement is the same but with M (molarity) Is this right? The small m means molality. If it were changed to capital M, then solution A's ...

chemistry
a student performs the lab on an unknown metal and obtain the following data

Chemistry
Net ionic equation for the reaction of strontium nitrate and sodium carbonate.

Chemistry
We did a lab about the heat hydration of sodium acetate with water. I got that the enthalpy of anhydrous sodium acetate is exothermic while the enthalpy of trihydrate sodium acetate is endothermic. Also that the enthalpy of the hydration of the sodium acetate salt is also ...

chemistry
How to balanced chemical equation and identify the type of reaction for solid ammonium nitrate decomposes into dinitrogen monoxide gas and water

Chemistry
How many grams of CaCl2 are needed to produce 10.0 grams of NaCl?

chemistry
You are making 40g of a 29% (w/w) sucrose solution. what amount of sucrose and water would be used. each in grams please

Chemistry
An aqueous solution of volume, v1 cm3, contains a mass, mg,of a compound to be extracted. When shaken with v2 cm3 of an organic solvent, a certain proportion, x, of this compound dissolves. Derives an expression for x in terms of v1, v2 and the partition coefficient, k.

chemistry
A patient is prescribed 0.210 mg of a drug that is available in 70 μg tablets. How many tablets are needed? (Remember that the number of significant figures does not matter because the number of tablets is being counted.)

Math, physics, chemistry
calculate total ionic strength of solution in which concentration of CuSO4 and Al2(SO4)3 is 0.1 molar

chemistry
In the reaction K2CrO4(aq) + PbCl2(aq) → 2KCl(aq) + PbCrO4(s), how many grams of PbCrO4 will precipitate out from the reaction between 500.0 milliliters of 3.0 M K2CrO4 in an excess of PbCl2?

Chemistry
Consider equation 3A+B=C+D. You react 4 moles of A with 2 moles of B. Which of the following is true? 1) Limiting reactant (L.R.) is one with higher molar mass 2) A is L.R. because you need 6 moles of A and have only 4 moles 3) B is L.R. because you have fewer moles of B than ...

Chemistry
How many mL of SCN^-1 and water to put in a 10 mL solution with 5 mL of Fe^3+ already in it?... We're finding those values to make standard solutions of 0.00 mM FeSCN^2+ 0.020 " 0.040 " 0.060 " 0.080 " 0.100 " I know that you have to use M1*V1=M2*V2,but I'm not sure where to ...

chemistry
Robin the Research scientist prepares 100 mLs of a solution of 100 mM of Tris HCl. What is the pH? and part two for this question Calculate the pH when the scientist adds 100 ul of 50% NaOH

Chem
2. Suppose a chemistry student made 2000. mL of 6.00 M HCl. He accidently spilled half of this solution on the floor. What is the Molarity of HCL left in the beaker? Explain the answer... - for this problem, would I use the eq'N, M1V1=M2V2. 3. What is the molarity of a sol'n ...

Chemistry
Robin the Research scientist prepares 100 mLs of a solution of 100 mM of Tris HCl. What is the pH? and part two for this question Calculate the pH when the scientist adds 100 ul of 50% NaOH I am confused since we do not know the conjugate base concentration so how to solve for...

chemistry
Calculate the pH values and draw the titration curve for the titration of 500 mL of 0.010 M acetic acid (pKa 4.76) with 0.010 MKOH. Calculate the pH of the solution after 490 mL of the titrant have been added. Calculate the pH of the solution after 500 mL of the titrant have ...

Chemistry
Robin the Research scientist prepares 100 mLs of a solution of 100 mM of Tris HCl. What is the pH? I am confused since we do not know the conjugate base concentration so how to solve for the pH

Chemistry
Calculate the number of liters of hydrogen gas at STP that could be produced by the reaction of 4.80g of magnesium with excess hydrochloric acid. Mg+HCl=MgCl2+H2

chemistry
How many mole of CL2 are needed to react with 2.0 mole Na?

Chemistry
What volume is occupied by 100 g of air at room temperature (d = 1.20 g/L)?

chemistry
How many mole of CL2 are needed to react with 2.0 mole Na?

Chemistry
cooking oil, a non-polar liquid, has a boiling point in excess of 200 degrees Celsius. Water boils at 100 degrees. how can you explain these facts, given the strength of water's hydrogen bonding?

chemistry
how can i make 30 ml, 0.227 mol of hydroiodic acid from 50 ml hydroiodic acid of 57 wt% in water?

chemistry
commercially available concentrated Hydrochloric acid is 37.0% w/w Hcl.its density is 1.18g/ml.using this information calculate (a)the molarity of concentrated Hcl,and (b)the mass and volume (in ml)of solution containing 0.315 mol of Hcl?

chemistry
How many grams of MgO are produced during an enthalpy change of -199 kJ? 2 Mg(s) + O2(g) → 2 MgO(s) ΔH = -1204 kJ

Chemistry
(1)Make 500 ML of 4N H3PO4. How many grams will be needed? (2) In a titration procedure, 20mL of 2N solution were required to titrate 5mL of an unknown solution. What is the normality of the solution? (3) How much of a 0.01M can be made from 20mL of 6M HCl? (4)How many grams ...

Chemistry
The human body “burns” glucose (C6H12O6) for energy. a. Write a balanced chemical reaction for the complete combustion of glucose to CO2(g) and H2O(l) such that the stoichiometric coefficient for glucose is 1. b. When 1.00 g of glucose are completely burned at 298.15 K and...

Chemistry
Calculate the Delta Hf of the OH- ion given that the Delta Hf (H2O) = -285.8 kJ mol-1.

Chemistry
How much heat (in kilojoules) is required to warm 11.0 g of ice, initially at -14.0 ∘C, to steam at 112 ∘C? The heat capacity of ice is 2.09 Jg−1∘C−1 and that of steam is 2.01 Jg−1∘C−1.

chemistry
Explain the first ionization energy of lithium is greater than that of sodium

chemistry
How many unpaired electrons for cr3+

chemistry
A solution of 25.0mL of 0.10mol/L hydroiodic acid is titrated with 0.10mol/L ammonia.Determine the pH at equivalence.

Chemistry 112
Can someone please explain to me how to calculate reaction order with respect to something? I've read this in my textbook, and I watched videos on YouTube, but I still don't understand. Please help.

Chemistry
How many liters would 1.000g of helium gas occupy at STP?

chemistry
Calculate ∆S universe for the process H2O (s) → H2O (l) given that ∆Hfusion = 6.02 kJ/mol and ∆S system = 22.1 J/K mol . Remember that ∆S surrounding = -∆Hsystem / T. a) -20oC b) 0oC c) 20oC

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