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Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

AP Chemistry Help!!
When you light a candle, the paraffin wax soon begins to melt. Paraffin wax is a covalent compound. Can you classify the melting of the wax as a chemical change or a physical change? If so, which is it? If you cannot classify it as chemical or physical, explain why not. ...

Chemistry
If 26.4 grams of nitrogen and 30.1 grams of oxygen combine to form nitrogen monoxide, how many grams of nitrogen monoxide must form? I am confused on how to do the math.

Chemistry
Determine the mass of CaCO3 in your TUMS tablet? The weight of the tablet was 0.013g Concentration of HCl was 0.1494 M Volume of HCl was 95 mL Concentration of NaOH was 0.1422 M The average amount it took to titrate was 2.13 mL I have determined that moles of HCl neutralized ...

chemistry
what mass of copper is deposited from copper sulfate when a current of 0.22 A is passed through the solution for 15 minute

Organic Chemistry
I honestly can't figure out how to draw this structure and it's especially difficult for online homework. I've used up 2 tries and only have one more left! Can someone please help? Thank you so much! CH3C≡C(CH2)3C(CH3)3

Chemistry
1) What volume of oxygen gas at 28 Celsius and 102 kPa is needed to react completely with 150 g of iron according to the following reaction. Fe(s) + O2 (g) FeO(s) 2) A bunsen burner is lit in a lab that at 24.7 Celcius and 1.07 atm. What mass of water is produced in the ...

Chemistry
The balanced equation for the synthesis of water is: 2H2 + O2 > 2H2O If I have 5.5 grams of water, at least how many grams of Oxygen gas was needed?

Chemistry
Iron (III) Oxide reacts with Aluminum to form Aluminum Oxide and Iron. If I have 255 g of Aluminum and unlimited Iron (III) oxide, how many grams of Iron will form? I am really not sure how to work with this. What does it mean when it says that the iron is unlimited, how would...

chemistry
how do you convert 7.5% w/v NaCI to mM

Chemistry
Calculate deltaH for the reaction NO (g) + O (g) ----> NO2(g) given following NO + O3 ----> NO2 + O2 deltaH=-198.9 kj O3 ---> 3/2 O2 deltaH= -142 kj O2 -----> O2(g) deltaH=495

science chemistry
Explain how Particles moves in solid lead,molten solid,gaseous lead in these three state of matter

Chemistry
A sample of metal has a mass of 24.28g, and a volume of 5.53 mL. What is the density of this metal

Chemistry
Acetone is a common solvent and has a density of 0.7899 g/mL. What volume of acetone has a mass of 28.7g

Chemistry
Does Oleic acid have larger molecules than water molecules? and what type of bonding does oleic bonds have?

Chemistry
Assume that you have a liquid in a cylinder equipped with a movable piston. There is no air in the cylinder, the volume of space above the liquid is 200 mL, and the equilibrium vapor pressure above the liquid is 29.0 mm Hg. What is the equilibrium pressure above the liquid ...

Chemistry
How much energy (in kilojoules) is released when 29.0 g of ethanol vapor at 88.0 ∘C is cooled to -10.0 ∘C? Ethanol has mp = -114.5 ∘C, bp = 78.4 ∘C, ΔHvap = 38.56 kJ/mol and ΔHfusion = 4.60 kJ/mol. The molar heat capacity is 113 J/(K⋅mol) for the liquid and 65.7 J...

chemistry
With information on the inside cover of the book, calculate how many mL of 70.4 wt% nitric acid should be diluted to 0.250 L to make 3.00 M HNO3. (Answer:47.5 mL)

Chemistry
The volume of a sample of a gas is 41.5 L at 8.28 atm and 467 K. What volume in L will it occupy at 3.03 atm at the same temperature?

chemistry
72g of Mg reacted with 32g of oxygen to form 48g of Mg. So %yield of Mgo

Chemistry
Hardness is defined as calcium and magnesium ion content. Since most hardness is caused by carbonate mineral deposits and does not distinguish calcium and magnesium ions, hardness is usually reported as parts per million (ppm) of calcium carbonate (CaCO3, by weight). A water ...

Chemistry
In this reaction: 2 HCl + Na2CO3 -> H2O + CO2 + 2 NaCl The HCl was diluted from 2M to 0.8M and I currently have 0.020 L of it. There is also Na2CO3. What would be four causes for a large error percentage? Is it possible that some of the HCl evaporated?

Chemistry
How much ice (in grams) be added to lower the temperature of 355 mL of water from 25 ∘C to 5 ∘C ? (Assume the following: the density of water is 1.0 g/mL, the ice is at 0 ∘C, the heat of fusion of ice is 6.02 kJ/mol, and the volume of water produced by the melting ice is...

Chemistry
Determine the mass of chlorine produced when 200A of current flows for 24 hours through a cell of molten NaCl.

Chemistry
Calculate the minimum time, in minutes, required to deposit 40g of copper using a current of 20A.

Chemistry
Write the symbol for the elements that fit the following descriptions 1. 10 electrons in each -3 ion 2. 18 electrons in each +2 ion 3. The alkaline earth metal in the third period

chemistry
H3PO4 + 3KOH = K3PO4 + 3 H2O What would be the percent yield if you reacted 49.0g of H3PO4 with 112g of potassium hydroxide, and collected 25.0g of water?

Chemistry
Radon-222 is a radioactive gas with a half-life of 4 days. Approximately how much of a 40 g sample of radon-222 would remain after 12 days?

Chemistry
If 23.2 grams of ammonium nitrite react to form 10.1 grams of nitrogen, how many grams of water must simultaneously be formed?

Chemistry
For the reaction of 2 HCl + Na2CO3 -> H2O + CO2 + 2 NaCl, how can I visually identify the limiting reagent, without any calculations? If I have a very high percent yield, what would be a good reason for it, considering that the HCl was diluted to 0.050 L at 0.8 M ...

Chemistry
"What volume of water must be added to 100ml of 15 M of H2SO4 to dilute to 5.0M?" I've tried using lots of different methods but keep having the same answer and don't know if the answer book is wrong or if it's me. Thanks!

chemistry
how many unpaired electrons are in this configuration 1s2 2s2 2p6 3s2 3p3

chemistry
how many unpeeled electrons are in this configuration 1s2 2s2 2p6 3s2 3p3

Chemistry help??!
A student reduces the temperature from a 300 cm3 balloon from 60°C to 20°C. What will the new volume of the balloon be? 264 cm3 <my answer choice 100 cm3 300 cm3 341 cm3

chemistry
which characteristics of solid, a liquid, and a gas are exhibited by each of the following substances? how would you classify each substance? A. a bowl of pudding will be solid and B. a bucketful of sand wiil be solid

chemistry
when water boils, there is bubbles that rise to the surface of the water. What is inside these bubbles? air

Chemistry
What is the oxidation state of Fe in Fe(CO)5

chemistry
The molecular formula of 2.68g hydrated sodium sulphate is Na2SO4.nH2O.If the mass loss on heating is 1.26g then calculate the value of n.

Chemistry
why homemade ice cream normally weighs twice the amount of commercially made ice cream

chemistry
The following unbalanced equation describes the reaction that can occur when lead (II) sulfide reacts with oxygen gas to produce lead (II) oxide and sulfur dioxide gas: PbS + O2  PbO + SO2. all i need help on is explaination of the electron transfers that would happen in ...

Chemistry
Assume that 5.00 grams of zinc react with excess HCl according to the following equation: Zn + 2HCl = ZnCl2 + H2 The hydrogen was collected over water at 20.0C and the prssure of the atmosphere is 751 mmHg. The pressure of the water vapor at 20C is 17.5 mmHg. How many moles of...

math sets
out of 320 students at a university,190 taking math,235 taking chemistry and 120 taking physics.125 are taking both chemistry and math,95 taking both chemistry AND PHYSIC,55 TAKING BOTH MATH AND PHYSICS.HOW MANY ARE TAKING ALL THE THREE SUBJECTS

Chemistry
How many moles of H are there in 8.9 moles of C4H8O2?

Chemistry
How many moles of Cl ions are there in 8.5 moles of CaCl2 ?

Chemistry
How to make 100 mL of 100mM of Tris HCl and 100 mL of 100mM of Tris Base. Follow the pH of the resulting combined solution as it is heated from 4 to 50 degrees Celsius. I did not use the HH equation in this problem. I started with just converting to moles needed and then to ...

Chemistry
How to Prepare 500mL a 50 mM pH 6 Citrate buffer starting from citric acid as the sole source of conjugate base I used the HH equation and got that citric acid concentration would be 0.035M, when converted to moles would be 3.362g. Then I was planning to add that amount to a ...

Chemistry
How is it possible that the atomic number increases in order, yet the atomic masses do not? A. There is no relationship between the atomic number and mass of the atom. B. The masses of the protons for Te, I, and Xe have slightly different masses. C. Since the numbers of ...

Chemistry
Which of the following best explains how relative atomic mass could be determined from the type of data available to Dalton? A. By determining the mass of oxygen contained in a sample of water, its exact atomic mass could be determined. B. By comparing the masses of hydrogen ...

Chemistry
2.40 L of N2, at 25 ∘C and 1.89 atm , is mixed with 2.60 L of O2, at 25 ∘C and 0.245 atm , and the mixture allowed to react. N2(g)+O2(g)→2NO(g) How much NO, in grams, is produced?

Chemistry
If we were to fill a bottle with boiling hot water than place it in a bucket filled with cold water what would happen to the bottle and why? i know the bottle would get crushed inwards but whats the science behind this can someone explain?

Chemistry
I'm doing a lab where I have to identify the oxidization state of Iron. Here's the procedure I had to go through: Use 0.5 molar concentration of CuSO4, get another beaker and add 0.1 grams of Iron to it. Add the CuSO4 to the beaker with the Iron fillings. Wait for the reaction...

chemistry
Your living room measures 45 ft by 62 ft. The cost of the carpet is $21/square yard. How much will you spend on carpet

chemistry
We have 1L of 0.1mol/l solution of ammonium chloride, with pKa 9.2 for NH4+/NH3 Place in an increasing order on a pKa axis the different conjugate acid /base pairs present in the solution. Write the equation of the different reactions that may take place

Chemistry
Calculate enthalpy of the reaction ethene+hydrogen gives ethane are -1410KJ,-286kJ and -1560KJ respectively at 25°c

Chemistry
In a certain reaction 0.20g of hydrogen gas combines with 3.20g of oxygen gas.if the relative molecular mass of the compound is 34.0 find its molecular formula (H=1,O=16).

Chemistry - Enthalpy
When a 37.00 g silver spoon, initially at room temperature, is placed into 250.0mL of 90.00oC tea, it reaches a temperature of 85.00°C. The spoon will have gained ? J of thermal energy. I got 5237.5 Joules as (mass)x(specific heat capacity)x(Temperature change)=Heat, which ...

Chemistry
What will burning of .3 liters of C2H2 produce?

chemistry
Calculate pH of 6ml of 3M HNO3 diluted to 18 litres of water

chemistry
1) Copy and complete: Two particles can react together only if they …… and the …… has enough …… to be ……. 2) What is meant by: a a successful collision? b an unsuccessful collision? 3) Reaction between magnesium and acid speeds up when: a)the concentration of ...

Chemistry
If you had a basketball that was filled with mercury, about how much would it weigh? (The density of mercury is 13.6 grams per cubic centimeter.) First Hint: If you do not know the dimensions of a basketball, you should ESTIMATE them.

Chemistry
A large balloon contains 65.0 L of helium gas at 25 °C and a pressure of 745 mm Hg. The balloon ascends to 3000 m, at which the external pressure has decreased by 30.%. What would be the volume of the balloon, assuming it expands so that the internal and external pressures ...

chemistry
Calculate the energies of the states of hydrogen atom with n=2 and n=3

Chemistry
Label the following changes as CHEMICAL or PHYSICAL change 1. Fat reacting with sodium hydroxide 2. Chemical A originally is buoyant in water; after it mixed with HCI, the new substance now sinks in water Label the following reactions as exothermic or endothermic 1. Ammonium ...

Chemistry
I am having trouble on a chemistry question for my study guide I have researched it and can't get an answer I understand can someone please help me? Describe what happened when an Ag+ combined with Na2CO3. What does this indicate?

Chemistry
What happens when equal volumes of 10^-5M of BaCl2 and 10^-5M of Na2SO4 are mixed at 25degree Celsius. Ksp of BaSO4=0.3×10^-10.

Chemistry
0.001N NaoH calculate the ph

chemistry
25cm cubed of 0.250mol per litre of potasium carbonate was nuetralized 12.5cm cubed of ethanoic acid of unknown concentration.determine concentration of the acid

chemistry
Calculate the energy required for ionization of electron from the ground state of hydrogen atom

chemistry
The reaction 2 NO(g) + O2(g) --> 2 NO2(g) is important in forming smog. Under certain conditions, the rate law for a the reaction is rate = 4.0 x 10-3 1/M2*s * [NO]2* [O2] What is the rate when [NO]=0.020 M and [O2]=0.035 M? a. 5.6 x 10-2 M/s b. 9.8 x 10-5 M/s c. 9.8 x 10-8...

chemistry
Calculate the concentration of KIO3(aq) present at the beginning of a reaction when 2.00 mL of 0.020 M KIO3(aq) is mixed with 8.00 mL of other solutions so the initial volume for the reacting mixture is 10.00 mL.

chemistry
Consider the reaction: N2(g) + 3 H2(g) --> 2 NH3(g). At a particular time, the nitrogen is being consumed at a rate of 0.60 moles/sec. At this same time, what is the rate at which ammonia is being formed? a. 3.0 mol/s b. 0.12 mol/s c. 0.30 mol/s d. 2.0 mol/s e. 1.2 mol/s

chemistry
The rate of a reaction A + 2B --> products is determined. When the concentration of A is 1.0 M, the rate of the reaction is 0.50 M/s. When the concentration of A is 0.50 M, the rate is 0.25 M/s. From this data, you can determine: a. that the reaction is second order in A. b...

chemistry
In a reaction, a chemist is observing the absorbance of CoCl2(aq) as a function of time to determine the rate at which it is being consumed in a reaction. At time t=10 s, the chemist determines that the concentration of CoCl2(aq) is 0.12 M. At time t=20 s, the chemist ...

Chemistry
why is a solution of copper sulfate and sulfuric acid required in corrosion testing? Won't the protons and the positive ions adhere to the metals surface and contaminant it?? Just a curious q. Thanks!

Chemistry
Calculate the number of grams of the indicated element in the compound. a) lead in 63.8 g PbO2 b) carbon in 1.664 g (CH3)2CO

CHECK MY CHEMISTRY WORK PLEASE ASAP
1. You have been given a sample of unknown molarity. Calculate the molarity of a solution which has been prepared by dissolving 8.75 moles of sodium chloride in enough water to produce a solution of 6.22l. 2. You have a sample which consists of 428g sodium hydroxide (NaOH) ...

Chemistry
What is an alcohol? Give a short definition. My answer: An organic compound in which one or more groups of hydroxyl is bonded to a chain of hydrocarbons. Do I need to change something of my answer to make it easier to understand? Thanks.

CHEMISTRY
You have been given a sample of unknown molarity. Calculate the molarity of a solution which has been prepared by dissolving 8.75 moles of sodium chloride in enough water to produce a solution of 6.22l. 2. You have a sample which consists of 428g sodium hydroxide (NaOH) ...

Chemistry
For the following reactions, determine the equilibrium constant equation. 1) CO2(g) + H2(g) CO(g) + H2O(g) 2) 2NO(g) + 2H2(g) N2(g) + 2H2O(g) 3) Cu(s) + 2Ag+(g) Cu2+(g) + 2Ag(s) 4) H2(g) + I2(g) 2HI(g)

Chemistry VERY DIFFICULT
Imagine you have been given a series of materials to react together and the following enthalpy change data has been recorded. Explain the terms exothermic and endothermic, and identify which of the following are exothermic and endothermic reactions. Ensure that you explain ...

Chemistry
1. You have been given a sample of unknown molarity. Calculate the molarity of a solution which has been prepared by dissolving 8.75 moles of sodium chloride in enough water to produce a solution of 6.22l. 2. You have a sample which consists of 428g sodium hydroxide (NaOH) ...

Science, Chemistry
A 1050.0 mL solution of NaOH is neutralized by 0.25 L of 2.00M Nitric Acid using Bromothymol Blue as an indicator. The concentration of the NaOH solution is 0.48M. True or False

chemistry
Calculate the energy required for ionization of electron from the ground state of hydrogen atom

chemistry
Ammonia reacts with copper(ll)oxide to give nitrogen gas, copper and steam. Balance the equation. If 18.1g of ammonia is reacted with 90.4g of coope(ll)oxide,how many moles of each reacts?,and how many grams of nitrogen are formed?

CHEMISTRY URGENT
1. You have been given a sample of unknown molarity. Calculate the molarity of a solution which has been prepared by dissolving 8.75 moles of sodium chloride in enough water to produce a solution of 6.22l. 2. You have a sample which consists of 428g sodium hydroxide (NaOH) ...

chemistry help asap please
You have been given a sample of unknown molarity. Calculate the molarity of a solution which has been prepared by dissolving 8.75 moles of sodium chloride in enough water to produce a solution of 6.22l.

CHEMISTRY
You have been given a sample of unknown molarity. Calculate the molarity of a solution which has been prepared by dissolving 8.75 moles of sodium chloride in enough water to produce a solution of 6.22l.

Chemistry
CuCO3=CuO +CO2. Find the mass of 1mole of each substance taking part in the reaction. (Ar:Cu=64,C=12,O=16). When 31g of CuCO3 is used; 1)how many grams of CO2 is formed. 2) what mass of solid remains after heating.

Science Chemistry
LIST: SODIUM CARBONATE. CALCIUM CARBONATE. ZINC SULFATE. ZINC NITRATE. (a) State a pair of chemicals from the list above that can be used to prepare zinc carbonate by precipitation reaction involving mixing 2 aqueous solutions together. (b) Write a chemical equation for the ...

Science Chemistry
LIST: SODIUM CARBONATE. CALCIUM CARBONATE. ZINC SULFATE. ZINC NITRATE. (a) State a pair of chemicals from the list above that can be used to prepare zinc carbonate by precipitation reaction involving mixing 2 aqueous solutions together. (b) Write a chemical equation for the ...

Science Chemistry
LIST: Sodium carbonate. Calcium carbonate. Zinc sulfate. Zinc nitrate. (a) State a pair of chemicals from the list above that can be used to prepare zinc carbonate by a precipitation reaction involving mixing 2 aqueous solutions together. (b) Write a chemical equation reaction...

chemistry
Calculate the maximum number of unpaired electrons that can be placed in a 6d subshell

chemistry
2Na + 2H2O---> 2NaOH + H2 Need to find the molecules of H2 Atomic wt o Na = 23 48.7 g of Na 48.71/23 = 2.12 mols Na 2.12/2 × 24. (WHERE DOES THE 24 COME FROM) = 25.44 dm^3 H. (PLEASE EXPLAIN THIS PART) = 1.06moles 1.06mols× 6.02×10^23 avagados number= 1.204 × 10^24 ...

CHEMISTRY
A 70g sample of iron ore(Fe2O3) was analyzed for Iron and found to contain 1700 Fe. Calculate the percentage of iron in the sample.

Chemistry
A 3 M HCL solution was used to generate the Co2 from the CaCO3. What would be the effect of substituting 6 M HCL for 3 M HCL? Explain

chemistry
writing blanced decomposition formula of Ammonium Carbonate

Chemistry
Given the reaction below, and your knowledge of the "Law of Conservation of Mass", what is the missing product from the chemical reaction? How do you know? Zn(s) + HCl(aq) --> ___ + ZnCl2(aq)

Chemistry
How many moles Of (Al2SO4)3 can be prepared from 2.5ml Of H2SO4

AP Chemistry
Dinitrogen pentoxide (N2O5) decomposes in chloroform as a solvent to yield NO2 and O2. The decomposition is first order with a rate constant at 45 degrees Celsius of 1.0*10^-5 s^-1.Calculate the partial pressure of O2 produced from 1.00 Liter of 0.600 M N2O5 solution at 45 ...

Chemistry
Mean titre of 0.2M sodium thiosulphate = 32.2 ml 1) Calculate number of moles of S2O32- which react in the titration 2)Calculate how many moles of I2 react with this amount of S2O3 3)How many Cu2+ ions are needed to liberate this amount of I2? Use this answer as the number of ...

chemistry
Calculatr morality of a solution containing 2.5g of K2CO3 in 1liter of solution (density of solution is 0.85 gram/ml

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