Thursday
July 28, 2016

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

Chemistry
What is the concentration of a monoprotic weak Acid if its pH is 5.50 and its Ka= 5.7 x 10^-10?
Thursday, July 28, 2016 by Joshua

Chemistry Grade 12
If the concentration of I^-1 is found to be 2.4 x 10^-3 mol/L in a saturated solution of PbI2. What is the Ksp of PbI2?
Thursday, July 28, 2016 by Kevin

Chemistry
Why wash water in experiment limiting reagent has to be kept warm at 80-90 degree celcius . Explain why
Thursday, July 28, 2016 by Uitm

Chemistry
I need to draw a line angle structure of ibuprofen that shows hydrogen bonding and I am stuck. Can anyone help?
Wednesday, July 27, 2016 by Breanne

Chemistry
You discover a new cell type that contains measurable amounts of silver ions (Ag+) in it. You find that the concentration of Ag+ inside the cell is still 10 times lower than the concentration outside. Calculate the amount of membrane potential that results from this amount of ...
Wednesday, July 27, 2016 by Tenshi

Organic Chemistry
Is helium considered a noble gas?
Wednesday, July 27, 2016 by Anonymous

Chemistry Grade 12
If the concentration of CN1- is found to be 1.4 × 10-6 mol/L in a saturated solution of AgCN, what is the Ksp of AgCN?
Wednesday, July 27, 2016 by Kevin

chemistry
15gm of sodium chloride is present in one kilogram of solution.express the concentratiom in ppm and ppb
Wednesday, July 27, 2016 by hussain

chemistry
what volumes of 6M hcl and 2M hcl should be mixed to get two litres of 3M hcl
Wednesday, July 27, 2016 by hussain

Chemistry
If 0.896g of a gas occupies a 250mL flask at 20 degree celcius and 760 mmHg of pressure, what is the molar mass of the gas?
Wednesday, July 27, 2016 by John

chemistry
what volume of a 0.5M solution of sulphuric acid is required to prepare 2 litres of a 0.4M solution of the acid
Wednesday, July 27, 2016 by Apoorva

chemistry
15mg of sodium chloride is present in 1kg of solution. express the concentration in ppm and ppb.
Wednesday, July 27, 2016 by Apoorva

Chemistry
Rank the following molecules in order of water solubility. ch3ch2ch2ch3, ch3oh, nacl, and ch3chohcooh
Tuesday, July 26, 2016 by Steph

chemistry
Dissolve 50g of sodium hydroxide in 1 litres and determine the normality
Tuesday, July 26, 2016 by Maryann

Chemistry
How much H3PO4 is needed to neutralize 1 liter of a 0.75M solution of NaOH? (in moles)
Tuesday, July 26, 2016 by Damon

Chemistry
Which value is most likely to be the pH of a salt that is formed by the reaction of a strong acid and a weak base
Tuesday, July 26, 2016 by RESHONDA

Chemistry
When zinc metal is reacted with hydrochloric acid, zinc chloride and hydrogen gas are produced. If 25ml of 0.2M HCl and 0.3g of zinc metal is used: a. how many M of zinc chloride will be produced? b. how many M of zinc chloride will be produced if 0.5M of HCl was used? c. how ...
Tuesday, July 26, 2016 by Eirin

Chemistry
What volume of nitrogen dioxide (in L) is produced from the complete reaction of 16.87 of lead (ii) nitrate at STP
Monday, July 25, 2016 by Damon

Chemistry
How much oxygen will we get from 120 grams of KClO3?
Monday, July 25, 2016 by Siam

Organic Chemistry
Why is helium considered a noble gas?
Monday, July 25, 2016 by Sevret

Chemistry
250ml solutions is prepared on dissolving 20g NaOH. Calculate the molarity of solution
Monday, July 25, 2016 by Diwaker

12th grade Chemistry
BOND BREAKING AND BOND MAKING: Determine by calculations and energy level diagrams, to proof whether these two reactions are endothermic or exothermic reactions.. 1. Methane burns in oxygen 2. Nitrogen (II) reacting with oxygen producing nitrogen monoxide.. please anyone just...
Sunday, July 24, 2016 by Barachiel

Chemistry
Why Fe(III) can be estimated in acidic medium by dicromet not by permanganet? — please give answer basis on value of reduction potential
Sunday, July 24, 2016 by yeasin

Chemistry
Determine by calculation and diagrames to proof whether these two reactions are endothermic or exothermic .. 1. Methane burns in oxygen 2. Nitrogen (II) reacting with oxygen producing nitrogen monoxide.
Sunday, July 24, 2016 by Barachiel

chemistry
pH of 1.0 x 10-8 M RbOH
Sunday, July 24, 2016 by Richard

chemistry
Nylon 88 is made from the monomers H2N(CH2)8NH2  and  HOOC(CH2)6COOH.  So, would you characterize nylon 88 as rather an addition or a condensation polymer? Please explain your answer
Sunday, July 24, 2016 by Chem

chemistry
Vanadium is an environmental pollutant originating from some types of steel, but also from the combustion of fossil fuels. The amount of V2+ in an unknown sample is determined by potentiometric titration by 7.62 mM permanganate ion, MnO4 - . 25.00 mL of unknown was titrated ...
Saturday, July 23, 2016 by siri

chemistry
You can temporarily receive relief from acid indigestion by using an antacid that contains a base. Why is it not a good idea to use an antacid routinely? (2 reasons)
Saturday, July 23, 2016 by Lara

Analytical Chemistry
I am having major issues with this problem and I no clue where to start. It also doesn't help that the professor never taught us how to calculate mass % from data like this... Students in the analytical chemistry class were given a sample of spinach to determine its iron ...
Friday, July 22, 2016 by Katie

Chemistry
A solution of 0.211 M NaOH is used to titrate 24.0 mL of a H2SO4 solution. If 19.0 mL of the NaOH solution is required to reach the endpoint, what is the molarity of the H2SO4 solution? H2SO4(aq)+2NaOH(aq)→2H2O(l)+NaSO4(​aq)
Friday, July 22, 2016 by Ava

Chemistry
Static charge can interfere with the production of plastic products by attracting dust and dirt. to reduce it, manufacturers expose the area to polonium-210, which has a half-life of 138 days. How much of a 25.0-g sample will remain after one year (365 days)? N = N0(1/2)t/T...
Thursday, July 21, 2016 by S

chemistry
how much ml of oxalic acid is needed to standardize 0.1M NaoH
Thursday, July 21, 2016 by Megha Sivadas

chemistry
molar solubility of nitrogen at 25 degree celcius
Thursday, July 21, 2016 by ahmed yousif ali

Math
In a group of 500 students, 150 are studying physics, 220 are studying biology, and 100 are studying chemistry. At least 25 students are studying more than one of these sciences. What is the greatest possible number of these students that might NOT be studying any of these ...
Wednesday, July 20, 2016 by Anonymous

Chemistry
For two questions below, first write and balance the equation for the chemical reaction.  Please, also review the material in Chapter 8, if you will feel you might need it in order to answer the questions.  Next, please answer the following questions: (a) ...
Wednesday, July 20, 2016 by Chem&Society

Chemistry
Express each aqueous concentration in the unit indicated. 45 ppm NO3 -, as molarity of nitrate ion in [mol NO3 - /L].
Wednesday, July 20, 2016 by Chem&Society

Chemistry
The atmosphere contains about 5.2 x1015 t of air.  What mass in metric tons of carbon dioxide is in the atmosphere if the concentration of CO2 is 395 ppm?
Wednesday, July 20, 2016 by Chem&Society

Chemistry
For the system, H2(g) + X2(g) <--> 2HX(g), Kc = 24.4 at 300 K. A system was charged with 2.00 moles of HX in a 3.00 liter container. The catalyst was introduced using a remote unit, and the system was allowed to come to equilibrium. How many moles of H2(g) will be ...
Wednesday, July 20, 2016 by Val

chemistry
Assuming all gases are at the same temperature and pressure, how many milliliters of hydrogen gas must react to give 41.0 mL of NH3? 3H2(g)+N2(g)→2NH3(g)
Wednesday, July 20, 2016 by Maria

Chemistry
How many grams of hydrogen peroxide (H2O2) must be added to 1,500 ml of water to produce a concentration of 1.33 m (molal solution)?
Wednesday, July 20, 2016 by Damon

Chemistry
For the teaction system, 2SO2(g) + O2(g) <--> 2SO3(g), Kc has a value of 4.62 at 450.0K. A system, at equilibrium, has the following concentrations: [SO3] = 0.254 M, [O2] = .00855 M. What is the equilibrium concentration of SO2(g)? The correct answer is 1.28M, but I don...
Wednesday, July 20, 2016 by Mikey

Chemistry
The human body obtains 885 kJ of energy from a chocolate chip cookie. If this energy were used to vaporize at 100 degree Celsius, how many grams of water could be vaporized? The heat of vaporization of water at 100 degrees Celsius is 40.7 kJ/mole.
Wednesday, July 20, 2016 by Jane

chemistry
The compete oxidation of 2g of an aldehyde A by acidified potassium chromate produces 2.1g of carboxylic acid B which is dissolved in 50 ml of distilled water . The obtained solution reacts with exactly 1.05 g of solid lime to form salt C a) Write the equation of the reaction ...
Wednesday, July 20, 2016 by dani

Chemistry
How many liters of HCl acid needed to dissolve at 1 ton of carbon and how long would it take?
Wednesday, July 20, 2016 by Derrick

Chemistry
How many grams of O2 are there in a 50.0L tank at 21*C when the pressure is 1.19x10^4mmHg?
Tuesday, July 19, 2016 by Brooke

Chemistry
The human body obtains 885 kJ of energy from a chocolate chip cookie. If this energy were used to vaporize at 100 degree Celsius, how many grams of water could be vaporized? The heat of vaporization of water at 100 degrees Celsius is 40.7 kJ/mole.
Tuesday, July 19, 2016 by Jane

Chemistry
At constant pressure , a certain gas occupies 80cm3 at 0 degrees, what wil be its volumd at 10 degrees
Tuesday, July 19, 2016 by Max

chemistry
what happens to water at 100 degrees celsius as pressure is increased fro 0.8 atm to 1.2 atm?
Tuesday, July 19, 2016 by barb

Chemistry
The boiling point of alcohol is 78.3 degrees Celcius at 760 mm atm pressure. Would the boiling point be higher or lower than 78.3 degree Celcius at hugher altirudes? Why?
Tuesday, July 19, 2016 by Chen

Chemistry
If 30ml of the standard sodium edetate soln neutralized 25ml of solution containing 0.25g of dried magnesium sulphate. Calculate the %w/v of mgso4 in the dried mgso4
Tuesday, July 19, 2016 by Kingsley Ekpe

CHEMISTRY
A compound which contains hydrogen, oxygen, carbon only has molar mass of about 85 g/mol. When 0.43 g of the compound is burned in excess of oxyfen, 1.10 g of CO2 and 0.45 g of H2O are formed. Find the molecular formula and the empirical formula of the compound
Monday, July 18, 2016 by Clive Lodnyx

chemistry
Hydrogen chloride reacts with water to produce an ion with the chemical formula H3O+. An H3O+ ion has one dative covalent bond. Explain how the bond is formed.
Monday, July 18, 2016 by Rose

Chemistry
For each of the following combinations of solutions, determine the mass of barium sulfate, BaSO4, that should precipitate...? For each of the following combinations of solutions, determine the mass of barium sulfate, BaSO4, that should precipitate. (Begin by writing a chemical...
Monday, July 18, 2016 by Juliet

Chemistry
For the reaction, calculate how many grams of the product form when 3.2 g of Na2O completely reacts. Assume that there is more than enough of the other reactant. Na2O(s)+H2O(l)→2NaOH(aq)
Sunday, July 17, 2016 by Javier

Chemistry
For the reaction, calculate how many grams of the product form when 3.2 g of Mg completely reacts. Assume that there is more than enough of the other reactant. 2Mg(s)+O2(g)→2MgO(s)
Sunday, July 17, 2016 by Leo

Chemistry
For the reaction, calculate how many grams of the product form when 3.2 g of CaO completely reacts. Assume that there is more than enough of the other reactant. CaO(s)+CO2(g)→CaCO3(s)
Sunday, July 17, 2016 by Rachel

Chemistry
For the reaction shown, calculate how many grams of oxygen form when each of the following completely reacts. 2HgO(s)→2Hg(l)+O2(g)
Sunday, July 17, 2016 by Marley

chemistry
what is the precipitate form of 2naoh+cuso4->na2so4+cu(oh)2
Sunday, July 17, 2016 by charshley

Chemistry
A CaCl2 solution is given to increase blood levels of calcium. If a patient receives 5.0 mL of a 5.0 % (m/v) CaCl2 solution, how many grams of CaCl2 were given?
Sunday, July 17, 2016 by Ava

Chemistry
A typical antacid contains CaCO3. If such an antacid is added to 25.0 mL of a solution that is 0.250 M in HCl, how many grams of CO2 gas are produced?
Sunday, July 17, 2016 by Maria

Chemistry
A patient received 5.0 g of NaCl in 8 hours. How many milliliters of a 0.40 % (m/v) NaCl (saline) solution were delivered?
Sunday, July 17, 2016 by maria

chemistry
what will be formed when oxygen combines with hydrogen in the presence of hydrated iron 3 oxide?
Sunday, July 17, 2016 by stephen

chemistry
Calculate the grams or milliliters of solute needed to prepare the following solutions. 1.)75. g of a 7.0 % (m/m) KCl solution 2.) 1250 mL of a 8.0 % (m/v) NH4Cl solution 3.) 270. mL of a 15.0 % (v/v) acetic acid solution I really just need to know how to work the first ...
Sunday, July 17, 2016 by maria

chemistry
Solubility (g/100gH2O) Substance 20∘C 50∘C KCl 34.0 42.6 NaNO3 88.0 114.0 C12H22O11 (sugar) 203.9 260.4 Using the above table, determine whether each of the following solutions will be saturated or unsaturated at 50 ∘C. 1.) Adding 19.7 g KCl to 35.0 g H2O 2.)...
Sunday, July 17, 2016 by maria

chemistry
a 51.6 litre sample of a pure allotrope of oxygen has a mass of 100.0 grams. (25 degrees celsius and 100 kPa) Show, by calculation, which allotrope of oxygen is present.
Sunday, July 17, 2016 by Anonymous

Chemistry
Write a balanced equation for the complete oxidation reaction that occurs when ethanol (C2H5OH) burns in air.
Sunday, July 17, 2016 by anonymous

Chemistry
0.110 M in formic acid and 5.5×10−2 M in hypochlorous acid . How to find pH
Saturday, July 16, 2016 by Sandov

Chemistry
Marcela dissolves 80.0 g of ammonium nitrate in 50.0 mL of water at room temperature and notes that the temperature of the solution decreases by 5.0°C. Which correctly designates the signs of changes of G, S and H for this reaction?
Saturday, July 16, 2016 by Damon

chemistry
Which is the more stable electron: that in a ground-state H atom or that in a ground-state He+ ion? Explain your choice.
Saturday, July 16, 2016 by ben10

chemistry
what is activation energy?
Saturday, July 16, 2016 by pat

Chemistry HELP!!!
Which of the following contains the greatest number of particles? A) 4g of helium gas B) 4g of oxygen gas C) 4g of hydrogen gas D) 4g of water Why is the answer C? Pls explain to me clearly, thks!
Saturday, July 16, 2016 by Cheezel Lim

chemistry
a given sample of MgCl2 solution has 6×10^23 ions. what is the number of Cl(-1) ions in the same solution?
Saturday, July 16, 2016 by hassan

Chemistry
A small section of a polymer chain, containing 10 repeating units, has a relative molecular mass of 625. Which of the following monomers could have polymerised to form this chain? ethylene viyl chloride styrene glucose
Saturday, July 16, 2016 by Anonymous

Chemistry
Hi, I've been working for nearly 2 hrs on this problem, but I'm stuck on the next step. Thanks for any pointers in the right direction. My problem is: How many grams of S8 are needed to produce 225 grams of sulfur hexafluoride? I was given this formula: S8+24F2(Arrow)...
Friday, July 15, 2016 by Amanda

Chemistry
How many grams of S8 are needed to produce 225 grams of sulfur hexafluoride? I know to begin with a balanced equation S8+24F2(arrow)8SF6. I've spent a couple of hours trying to figure out the next step, but I'm stuck. Thanks for any pointers!
Friday, July 15, 2016 by Darius

chemistry
What volume of 0.10 M NaOH can be prepared from 250. mL of 0.30 M NaOH? A) 0.075 L B) 0.25 L C) 0.75 L D) 0.083 L E) 750 L
Friday, July 15, 2016 by maria

Chemistry
What volume of nitric dioxied at s.t.p from the below equestion N2+O2=2NO
Friday, July 15, 2016 by Shukulu

Chemistry (DUE TONIGHT)
A possible reaction for converting methanol to ethanol is: CO(g) + 2H2(g) + CH3OH(g) -----> C2H5OH(g) + H2O(g) I completed parts A-C correctly, and found the following info: delta H = -165.6 kJ delta S = -227.4 J/K delta G = -97.9 kJ The next question is asking to estimate ...
Friday, July 15, 2016 by LC

chemistry practical
Why? alkaline solution didn't puppet out.
Friday, July 15, 2016 by Vishal Hood

chemistry
Calculate the no. Of moles of co2 is liberated gives50gm of caco3 reacts with 7.3gm of dil.hcl
Friday, July 15, 2016 by Siddhartha

chemistry
Discuss the structure of bonding in copper acetate?????
Friday, July 15, 2016 by prakash

college chemistry
prepare 0.2M phospate buffer of pH 5.7
Thursday, July 14, 2016 by rajan

Chemistry
N2H4 + 2H2O2= N2 + 4H2O What are the mole ratios of hydrazine (N2H4) to hydrogen peroxide (H2O2) and hydrazine to water
Thursday, July 14, 2016 by Damon

Chemistry
In the reaction C + O2 → CO2, 18 g of carbon react with oxygen to produce 72 g of carbon dioxide. What mass of oxygen would be needed in the reaction?
Thursday, July 14, 2016 by Mariah

Chemistry
1.06g of Na2CO3 is dissolved in water to make 250cm^3 solution. 10.0 cm^3 of this solution was further diluted to make 500cm^3 of 2nd solution. 25.0cm^3 of 2nd solution reacted with 28.5cm^3 of HCl. Find the concentration of HCl in mol/dm^3
Thursday, July 14, 2016 by Gary

Chemistry
Why water can be used as a solvent in paper chromatography?
Thursday, July 14, 2016 by Steph

Chemistry
Why do different substances have different Rf values ? used in chromatography.
Thursday, July 14, 2016 by Stephenie

pharmaceutical physical chemistry
find the density of NH3 gas at 100celsius when confined by a pressure of 1600mmHg
Thursday, July 14, 2016 by gladiza

Chemistry
Write a net ionic equation for the reaction that occurs when aqueous solutions of sodium hydrogen sulfite and potassium cyanide are combined.
Thursday, July 14, 2016 by Jise

Chemistry
Write a net ionic equation for the reaction that occurs when aqueous solutions of potassium fluoride and ammonium chloride are combined.
Thursday, July 14, 2016 by Jon

Chemistry
Write a net ionic equation for the reaction that occurs when aqueous solutions of ammonium chloride and sodium hydroxide are combined.
Thursday, July 14, 2016 by Ben

Chemistry
Write a net ionic equation for the reaction that occurs when aqueous solutions of potassium fluoride and bromic acid are combined.
Thursday, July 14, 2016 by Alice

Chemistry
The reaction 2NO (g) + 2H2 -> N2 (g) + 2H2O (g) was found to follow the rate law, rate = k[NO]^2[H2]. By what factor will the rate of reaction increase when the pressure of NO gas is increased from 2.0 atm to 3.0 atm? Assume all other conditions are held constant. I'm ...
Wednesday, July 13, 2016 by Mikey

chemistry
How much heat is produced by the complete combustion of 287 g of CH4? CH4(g)+2O2(g)→CO2(g)+2H2O(g)Δ​H∘rxn=−802.3kJ
Wednesday, July 13, 2016 by Anonymous

Chemistry
How many molecules are in 5.2L of carbon dioxide gas?
Wednesday, July 13, 2016 by Joey

Chemistry
What is the test for ammonium formed on hubber process? i need your help
Wednesday, July 13, 2016 by RONALD KAZEYA

Chemistry
hydrogen sulfide reacts with sulphur dioxide to give water and S, balance the equation. if hydrogen sulfide contains 125g, how much S is produced?
Wednesday, July 13, 2016 by Love

Chemistry
hydrogen sulfide reacts with sulphur dioxide to give water and S, balance the equation. if hydrogen sulfide contains 125g, how much S is produced?
Wednesday, July 13, 2016 by Love

Chemistry
If you are asked to make exactly 1.0 Liter of 0.80 M ZnCl2 solution, how many grams of zinc chloride would you need to be massed out? How do I go about solving this problem?
Wednesday, July 13, 2016 by Annie

Chemistry
All the following are necessary parts of a neutralization reaction except A) an acid B) an indicator C) water D) a salt.
Tuesday, July 12, 2016 by Mariah

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Homework Help: Science