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Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

Chemistry
I have a 0.6573g mixture of NaHCO3 and Na2CO3. Calculate the mass of NaHCO3 and Na2CO3 in the unknown mixture.Also calculate the mass of NaCl formed in the reaction of the mixture and HCl.

Chemistry
A 75.0g sample of liquid contains 17.5% by mass of H3PO4 (molar mass = 98.0g/mol). If 215.0mL of Ba(OH)2 is needed to completely neutralize the acid, determine the concentration of the Ba(OH)2 solution used

Chemistry
Determine the mass of urea, CH2N2O, required to make 250mL of a 0.235 M solution

Analytical chemistry
Calculate to four decimal places the mass of pure dry CaCO3 required to make 1 L of a 1000 ppm Ca stock solution.

Chemistry
Heat from burning a fuel is absorbed by a copper calorimeter. The calorimeter has a mass of 81.34 g and contains 200.0 g of water initially at 21 degrees Celsius. a) How much heat was absorbed by the calorimeter and the water if the final temperature of the water is 36.40 ...

Chemistry
How much heat is required to melt 110g of ice at-45°C?

Chemistry
What is the maximum mass, in grams, of NH3 that can be produced by the reaction of 1.0 g of N2 and 1.0 g of H2 using the reaction below? N2+H2→NH3 (not balanced) A) 0.60 g B) 5.7 g C) 1.2 g D) 2.9 g

Chemistry
The number of moles of cl2 produce will be ??????? If one mole of pcl5 is heated at 250 in a vessel having a capacity of 10dm³.

Chemistry
Magnesium oxide can be made by heating magnesium metal in the presence of oxygen. The balanced equation for the reaction is: 2Mg(s)+O2(g)→2MgO(s) When 10.1 g of Mg are allowed to react with 10.5 g of O2, 14.5 g of MgO are collected. a) Determine the limiting reactant for...

Chemistry
What is the maximum mass, in grams, of NH3 that can be produced by the reaction of 1.0 g of N2 and 1.0 g of H2 using the reaction below? N2+H2→NH3 (not balanced) What is the maximum mass, in grams, of that can be produced by the reaction of 1.0 g of and 1.0 g of using ...

chemistry
If 20 grams of zinc reacts with hydrochloric acid, how much zinc chloride is produced?

Chemistry
Assuming 100% dissociation, calculate the freezing point and boiling point of 2.45 m Na2SO4(aq). Constants may be found here sites. google. com/site/chempendix/colligative.

chemistry
A 2.41 g lead weight, initially at 10.7 ∘C, is submerged in 8.08 g of water at 51.9 ∘C in an insulated container. Question: What is the final temperature of both the weight and the water at thermal equilibrium? Express the temperature in Celsius to three ...

chemistry
A volume of 115 mL of H2O is initially at room temperature (22.00 ∘C). A chilled steel rod at 2.00 ∘C is placed in the water. If the final temperature of the system is 21.40 ∘C , what is the mass of the steel bar? Use the following values: specific heat of ...

chemistry
increasing order of boiling points of NO2, KCl and N2

Chemistry
A sample of gas occupies 100ml at 25 degree celsius. What volume would the gas occupy at 32 degree celsius if the pressure remains constant

chemistry
what is the reaction between potassium chloride and bromine?

Chemistry
In the laboratory you will be provided with a 1.0 x 10-5 M primary stock solution of fluorescein (MW=332.31g/mol). The calibration curve should include a blank, 0.025, 0.05, 0.075, 0.10, 0.15, and 0.25 micromolar fluorescein solutions. Since you will be using 25 mL volumetric ...

chemistry
Calculate the number of CO2 molecules in 7.30×10−2 mole of CO2. Express your answer using three significant figures.

chemistry
Calculate the number of Li atoms in 3.0 moles of Li. Express your answer using two significant figures.

chemistry
0.350 L of 0.470 M H2SO4 is mixed with 0.300 L of 0.250 M KOH. What concentration of sulfuric acid remains after neutralization?

Chemistry
You are handed a well insulated container holding about 100ml of water at a temp between 75 deg C and 100 deg C. you are given a thermometer with a maxmimum temp of 50 deg C. create an experiment to determine the temp of the water. i am really confused on how to start this ...

Chemistry
In the laboratory you will be provided with a 1.0 x 10-5 M primary stock solution of fluorescein (MW=332.31g/mol). The calibration curve should include a blank, 0.025, 0.05, 0.075, 0.10, 0.15, and 0.25 micromolar fluorescein solutions. Since you will be using 25 mL volumetric ...

Chemistry
When 13.0 grams of acetylene, C2H2, is reacted, what mass of water, H2O, is produced?

chemistry
what is the skeleton chemical equation of this? And Balanced equation. Copper (ii) chloride + Lithium --> Lithium Chloride + Copper

chemistry
what is the skeleton chemical equation of this? And Balanced equation. Copper (ii) chloride + Lithium --> Lithium Chloride + Copper

Organic Chemistry
Explain why the formation of one geometric isomer is favored over the other?

Chemistry
Solid AgNo3 is added slowly to solution of 0.001M Cl,Br,and I a) at what concentration of Ag will AgI precipitating? at what concentration of Ag will AgCl precipitating? at what concentration of Ag will AgBr precipitating? b) calculate the percent % of I ppt before reaching of...

Chemistry
1) How does the atomic radius change from left to right across a period in the periodic table? A) It tends to decrease*** B)It tends to increase C) It first increases, then decreases D) It first decreases, then increases 2) What is the charge of a cation? A) A positive charge...

chemistry
Gold has a latent heat fusion of 64.5 J/g. How much energy is required to melt 20.0 g of gold?

chemistry
Ethyl alcohol has a heat of vaporization of 850. J/g. What mass of ethyl alcohol can be boiled using 15000 J of energy?

Chemistry
Determine the volume of a 67.5g piece of aluminum with density of 2.70 g/mL? -I know V=M/p and this is what I came up with but I'm not sure i'm correct.. p = 2.7 g/cm3 M = 67.5 g V = 25 cm3 3√ V = 2.9240177382129 cm

chemistry
A student melts 50.0 grams of ice using 16650 J of energy. What is the heat of fusion of ice?

Chemistry
Determine the mass of 18.7mL of rubbing alcohol with a density of 0.79 g/mL? - I got 14.77. I'm not sure I'm right. If someone could clarify I'd appreciate it! Thanks!

Chemistry
A 1.75 gram perfect cube of wood has a side measure of 2.45 cm, what is the density of the wood?

Chemistry
I Just don't know what to do, I think I understand, but im not sure because all of the compounds are liquid. I would know how to do it if they were aqueous, and just the water is liquid, but they are all liquid. Determine the acid dissociation constant for a 0.10 M acetic acid...

Chemistry
Solid AgNo3 is added slowly to solution of 0.001M Cl,Br,and I a) at what concentration of Ag will AgI precipitating? at what concentration of Ag will AgCl precipitating? at what concentration of Ag will AgBr precipitating? b) calculate the percent % of I ppt before reaching of...

Chemistry
What volume of 17 M sulfuric acid must be used to prepare 0.15 L of 1.78 M H2SO4?

Chemistry
How many moles of magnesium chloride are in 5.43 x 10^24 formula units of magnesium chloride?

Chemistry
A student measures the molarity of a solution of sodium hydroxide as 0.247M. He leaves the solution in a beaker overnight and then titrates the solution again. This time he is surprised to get a result of 0.225M. Why should he have expected something of this nature?

Chemistry
Write the balanced equations for the reactions: a) Reduction of Ag+ Ions with metal Fe. b) Oxidation of metal Mg with Cu2+ ion.

CHEMISTRY HELP PLEASEEEE
Sulfuric acid is a diprotic acid, strong in the first ionization step and weak in the second (Ka2=1.1X10^-2). Using appropriate calculations, determine whether it is feasible to titrate 10.00mL of 0.1 M H2SO4 to two distinct equivalence points with 0.1 M NaOH.

Chemistry
Gives isomeric compound of C3 H8 O woth IULAC names

Chemistry
if the density of 2-butanol is 0.80g ml-1, what volume of 2-butanol would be produced from 1kg of butene

Chemistry
Since the unkown acid is monoprotic, this also equals the number of moles of acid to use. A typical molar mass for an unknown acid in this experiment is 380 g/mol. Using this molar mass, calculate the mass (in grams) of unknown acid you should use per titration. 1.Suppose that...

Chemistry
1. Suppose that 10.2 mL of 0.0512 M NaOH were required to titrate a sample of unkown acid. How many moles of NaOH were used?

Chemistry
Why was etching needed to bring out the grain boundaries? My answer: Is it for the light to bounce back?

Chemistry
What mass of calcium citrate, Ca3(C6 H5 O7)2, would a tablet manufacturer need to use to provide the same amount of Ca that you found in your tablet? (show calculations) The mass of Calcium for the experiment was .7374g We assumed that any solid that formed when Na2CO3 was ...

Chemistry Plz Help!
How to calculate dimensional analysis using the density and molarity to calculate the percent (w/w)???

Chemistry
0.5g of MG ribbon is reacted with 100ml of 1M HCL. The initial temperature of HCL is 20.4 degrees celsius. After the reaction the highest recorded temperature is 40.7 degrees celsius. Calculate the molar enthalpy of MG. I tried to find mol from HCl and then use nH=mcdeltat. ...

Chemistry
The molar enthalpy of combustion of demand is -6.78KJ/mol.What mass of decane would have to be burned in order to raise the temperature of 500ml of water from 20 degrees Celsius to 55 degrees celsius. I tried using ndeltaH=mcdeltat. But it didn't work. Please help

Chemistry
1) How does the atomic radius change from left to right across a period in the periodic table? A) It tends to decrease*** B)It tends to increase C) It first increases, then decreases D) It first decreases, then increases 2) What is the charge of a cation? A) A positive charge...

Chemistry
Calculations involving a limiting reactant Now consider a situation in which 20.0 g of P4 is added to 54.0 g of Cl2, and a chemical reaction occurs. To identify the limiting reactant, you will need to perform two separate calculations: 1) Calculate the number of moles of PCl5...

Organic Chemistry
Butanamide (Amide) vs Aminobutane (Amine) Which compound do you think has the higher melting point? Explain your reasoning.

Science (Chemistry) Ratio of mole
You measured out 0.101g of Mg. You heat the sample and measure out 0.234 of the magnesium oxide compound. Given your data, what us the empirical formula for the Mg(x)O(y)? x and y are ratio x:y If I'm doing this correctly, I divided 0.101g of Mg/24.31g of Mg = .00415 mol Mg ...

chemistry
Calculate the mass of pure NaCl that will yield enough HCl gas to neutralize 25cm3 of 0•5 of KCO3 solution

chemistry
5. One hundred milligram of caffeine is dissolved in 50 mL of water. a. How many mg of caffeine will remain in the water if you extract with 20 mL of methylene chloride? Show your calculations (KD = 4).b. How many mg of caffeine will remain in the water if you extract two ...

chemistry
The 17.35 g of NaCl sample was dissolv ed in an unknown amount of water. All we know is that prepared solution has 22.5% of NaCl . The mass of water is _____ g.

Chemistry
A sample of cobalt, A, with a mass of 5g is initially at 25 degrees Celsius. When this sample gains 6.70J of heat, the temperature rises to 27.9 degrees Celsius. Another sample of cobalt B with a mass of 7 g is initially at 25 degrees Celsius. If sample B gains 5 J of heat, ...

Chemistry
A solution of potassium permanganate (KMnO4) was standardised by titrating with 0.1908 g of Na2C2O4 dissolved in 50 cm3 of acidified water. The endpoint was reached after 24.50 cm3 of solution had been added. Calculate the molar concentration of KMnO4 in the solution.

Chemistry
A solution of potassium permanganate (KMnO4) was standardised by titrating with 0.1908 g of Na2C2O4 dissolved in 50 cm3 of acidified water. The endpoint was reached after 24.50 cm3 of solution had been added. Calculate the molar concentration of KMnO4 in the solution.

Chemistry
Calculate the molarity of Fe(NO3)3 in Solution A. Solution A: Mass of Fe(NO3)3 solid: 1.21g & Vol of Solution: 100mL In a previous ? Using the mass I weighed 404.0g/mol to calculate moles of Fe(NO3)3 in solid hydrate----I got 0.00300 mol Fe(NO3)3)

Inorganic Chemistry
A 1.577 M solution of AgNO3 has a density of 1.220 gram per centimeter cube. What is the molality of the solution?

Inorganic Chemistry
What is the mole fraction of solute in a 1.00 molal solution in which toluene (C7C8) is the solvent.

Inorganic Chemistry
Methyl Alcohol (CH3OH) and ethyl alcohol (C2H5OH) form ideal solutions at 50°C, the vapor pressure of pure methyl alcohol is 0.529 atm, and the vapor pressure of pure ethyl alcohol is 0.292 atm. What is the vapor pressure at 50°C of a solution containing 24.00 g of methyl ...

Inorganic Chemistry
what is the molarity of concentrated hydrogen fluoride if the solution is 48% by mass and has a density of 1.17 gram per milliliter.

Chemistry
A hypothetical pure element consists entirely of two isotopes. The natural percent abundance of the isotope with mass 25.5 u is 78.8 percent. The other isotope has mass 29.5 u. Calculate the atomic weight of the naturally occurring element.

maths
In a class of 60 students,the number of students who passed biology is 6 more than the number who passed chemistry.Every student passed at least one of the two subjects.i.how many students passed biology ii.how many students passed chemistry iii.how many students passed only ...

chemistry help
Chlorine has two Isotopes with mass number of 35&37.if the relative atomic mass is 35.5, find the percent abudance of Cl-35(isotope with mass number 35)

Chemistry
what is the energy if a photon of red light that has a wavelength of 8.90x10^-7

Chemistry
What is the total no. Of atoms present in 25.0 mg of camphor

chemistry
No. Of atoms in 12g of Mg is equal to

Chemistry a level
A solution of potassium permanganate (KMnO4) was standardised by titrating with 0.20 g of Na2C2O4 dissolved in 50 cm3 of acidified water. The endpoint was reached after 23.10 cm3 of solution had been added. Calculate the molar concentration of KMnO4 in the solution.

chemistry
what is the type of catalyst that corresponds the use of the platinum wire

Chemistry
What is the maximum mass, in grams, of NH3 that can be produced by the reaction of 1.0 g of N2 and 1.0 g of H2 using the reaction below? N2+H2→NH3 (not balanced) What is the maximum mass, in grams, of that can be produced by the reaction of 1.0 g of and 1.0 g of using ...

chemistry
Zinc react with diluted sulfuric acid to give hydrogen but silver doesn't explain?

Chemistry
A sample of acetone having a mass of 1.920 g undergoes complete combustion in an insulated calorimeter holding 400 mL of water. It is determined that the water and calorimeter together absorb 58.829 kJ of heat energy from this combustion. Based on this information, what is the...

Chemistry
A reaction in a calorimeter containing 80.0 g of water at 20 degrees Celsius causes the temperature to fall by 1.5 degrees. what is the thermal energy of the water? I got 6.2 J or 6192.32 kJ but they say 5.02 x 10^4 kJ idk what I am doing wrong

chemistry
Back to the atomic emmission spectrum and the atomic theory. in the 1900s, scientists observed that when a gaseous element, such as hydrogen was subjected to an electric discarge that the atoms emitted electromagnetic radiation. The light emmitted could be separated into ...

chemistry
Explain how understanding of the atomic emmission spectrum led to developement of the atomic theory. The emmissions spectrum for each element is unique. You can identify an eleement by its spectrum. The atomic theory states that all atoms of a given element are identical. The ...

Chemistry
Rain drops fall on a tile surface at a density of 4380 drops/ft^2. There are 15 tiles/ft^2. How many drops fall on each tile? Answer in units of drops/tiles.

Chemistry
Describe in detail how you would make 1.25 of 0.125 M potassium permanganate solution. I think you have to set up an equation for molarity but I'm not sure. Please help.

CHEMISTRY
The specific heat of copper is 0.386 J/gºC. A 20.0 g sample of copper is heated from 25.0 ºC to 35.0 ºC. How much heat did the copper absorb?

chemistry
Consider the reaction below. C3H8 + 5 O2  3 CO2 + 4 H2O How many litres of CO2 will be produced when 10.0 L of O2 are completely reacted with C3H8? Assume that the volumes of the reagents and products are measured at constant pressure and temperature.

chemistry
75.0 mL of a 1.50 M solution is diluted to a total volume of 278 mL. A 139-mL portion of that solution is diluted by adding 139 mL of water. What is the final concentration? Assume the volumes are additive.

Science-chemistry
How do I calculate the amount of heat will be required to make 100.0kg of a compound, the molar enthalpy is -63kj/mol for the same compound

science (chemistry)
The % (by weight) of methanol in a mixturevof methanol and ethanol is50%.Therefore,the mole fraction of methanol in the mixture is

Chemistry
Two substances, gold and granite, initially at different temperatures, come into contact and reach thermal equilibrium. The mass of gold is 20.2 g and its initial temperature is 58.2 ∘C. The mass of granite is 29.1 g and its initial temperature is 20.1 ∘C. What is ...

chemistry
Element x Isotope 55x 60% Isotope 56x 30% Isotope. 57x 10% 55× 60 =3300 56×30=1650 57× 10= 570 Add them up5520 divide by 100 the atomic weight of x is 55.2 Pls check if this is correct , answer and method

general chemistry
2C6H6(l)+15O2(g)-> 12CO2(g)+6H20(l)+6542 kj If 6.200 g of C6H6 is burned and the heat produced from the burning is added to 5691 g of water at 21 °C, what is the final temperature of the water?

Chemistry
In order to determine the concentration of a solution of Carbonic Acid (H2CO3), a sample was placed in a buret and titrated with 0.1132 M Sodium hydroxide. For the carbonic acid, the initial reading was 11.0ml and final reading was 31.0 ml. For sodium Hydroxide, the initial ...

chemistry 11
i did a lab on separation of salt and sand. the initial mass that my teacher gave me was the stock mixture that was: salt= 54.79g; sand= 97.90g. after the experiment my mass were as follow: salt= 1.35g; sand= 3.17g. question #1 was asking about the % composition of the mixture...

chemistry 11
i did a lab on separation of salt and sand. the initial mass that my teacher gave me was the stock mixture that was: salt= 54.79g; sand= 97.90g. after the experiment my mass were as follow: salt= 1.35g; sand= 3.17g. question #1 was asking about the % composition of the mixture...

chemistry
After the suction filtration, the filtrate in the suction flask contains (among other things) some dissolved product, which had failed to crystallize. Could you process this filtrate to obtain a sample of the product? Explain. Would the second crop of crystals be as pure as ...

chemistry
draw the skeletal structure line-angle (line-bond) mode of 2-isopropyltoluene. Identify the number of hydrogen atoms bound to each carbon in the structure.

Chemistry
If a reaction was started with 3 mL of TEOS in H2O and yielded 0.3275 grams of SiO2. what is the percent recovery of SiO2?

college chemistry
how many L @STP if oxygen are needed to produce 45.0 grams of nitric oxide according to the following balanced chemical equation? 4NH3 + 5O2=4NO + 6H2O

Chemistry
Assume that the reaction was limited by the surface area of the nails, making Fe the limiting reactant. Based on the decrease in the mass of nails, calculate theoretical yield of copper. 2Fe+3CuCl2--->2FeCl2+3Cu

Chemistry
Write a balanced equation assuming iron oxidizes to iron (II). I used CuCl_2 in the experiment.

chemistry,
Could you pls check back a few questions. The first 1 or 2 digits in each nmber is the family number, so the numbers do not go on a consistant trend. Thank you

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