Monday
January 16, 2017

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

Chemistry
What mass of zinc metal would be needed to produce 0.5 litre of hydrogen gas from dilute HCl
Tuesday, December 27, 2016 by Alex

chemistry
The label of a bottle containing a solution So of hydrochloric acid carries the following indications :hydrochloric acid of density 1190g/l percentage by mass 37%. We introduce a volume V=4.2ml of So in a volumetric flask of volume 500ml containing about 100ml of distilled ...
Tuesday, December 27, 2016 by vicky

chemistry
One has a solution Sa of ethanoic acid of concentration Ca=1×10^-2 mol/l and pH=3.4  One mixes a volume Va=60ml of the solution Sa of ethanoic acid with a volume Vb1=20ml of the Sb1 solution of ammonia of concentration Cb1=2×10^-2 mol/l. ...
Tuesday, December 27, 2016 by vicky

Chemistry
An ion x3-has 16 neutrons and an electronic configuration of2.8.8 determine 1]th number of protons in an atom x 2]the atomic mass of x
Tuesday, December 27, 2016 by Edith

Chemistry
a domestic cleaner contains concentrated hydrochloric acid as the active ingredient. a titration experiment was carried out to determine the concentration of hydrochloric acid in the domestic cleanser. 20.0mL of the cleanser were diluted to 250.0mL with distilled water. 25.0mL...
Monday, December 26, 2016 by Darth Chan

Chemistry
A given volume of ozone diffused from a certain apparatus in 96seconds calculate the time taken by an equal volume of carbonoxide to diffuse under the same condition?
Monday, December 26, 2016 by Zeugen reezy

Chemistry
Discuss the expansion of an ideal gas and changes in thermodynamic properties (3 marks)
Monday, December 26, 2016 by Anonymous

Applied Science Chemistry
A 0.5g mixture of Cu and CuO was treated with hydrogen at elevated temperature. CuO was reduced to Cu. Q1.) write a balanced equation for the reaction Q2.) before the experment, calculate the minimum amount in mole of hydrogen required to ensure the reduction is completed
Monday, December 26, 2016 by Darth Chan

chemistry
One has a solution Sa of ethanoic acid of concentration Ca=1×10^-2 mol/l and pH=3.4 One mixes a volume Va=60ml of the solution Sa of ethanoic acid with a volume Vb1=20ml of the Sb1 solution of ammonia of concentration Cb1=2×10^-2 mol/l. The pH is 5 ...
Sunday, December 25, 2016 by vicky

chemistry
The label of a bottle containing a solution So of hydrochloric acid carries the following indications :hydrochloric acid of density 1190g/l percentage by mass 37%. We introduce a volume V=4.2ml of So in a volumetric flask of volume 500ml containing about 100ml of distilled ...
Sunday, December 25, 2016 by vicky

chemistry
In equation He +Br2------>2HI why chemical rate of Br2 is taken as 1/2 . It's a reversible reaction. Please explain in detail. While H2 rate is taken as 1 why?
Saturday, December 24, 2016 by sanjay

chemistry
In equation He +Br2------>2HI why chemical rate of Br2 is taken as 1/2 . It's a reversible reaction. Please explain in detail. While H2 rate is taken as 1 why?
Saturday, December 24, 2016 by sanjay

chemistry
A domestic cleanser contains concentrated HCl as the active ingredient. A titration experiment was carried out to determine the concentration of HCl in the domestic cleanser. 20.0 ml of the cleanser were diluted to 250.0 ml with distilled water. 25.0 ml of the diluted cleanser...
Saturday, December 24, 2016 by henry39

chemistry
A) A solution was prepared by dissolving 1.113 g of MgCl2 into water and made up to 50.0 ml, calculate the molar concentration of the solution. B) A 250.0 ml of 0.50 M solution of Na3PO2 solution was prepared by diluting 2.5 M of stock solution. Calculate the volume of stock ...
Saturday, December 24, 2016 by henry39

Chemistry
How many litres nitric acid 70% w/w and how many litres of water do I need to prepare a 47 v% nitric acid solution. Please help.
Saturday, December 24, 2016 by Clare

Chemistry
Hi, How do you know how many ligands a metal ion needs to form a complex ion? So for example, with (Fe(H20)6)2+, how am I supposed to know that the Fe needs 6 H20's, rather than 4? Thank you!
Thursday, December 22, 2016 by Maria

Chemistry
I have asked this question before but I was not clear enough. I want to prepare a 37% w/w solution (in water)of sulfuric acid from 96% sulfuric acid. I need around 500ml, I know it won't be exactly that, I want to know how to use the conversion using density, I've been...
Thursday, December 22, 2016 by Pam

chemistry
A 0.50 g mixture of Cu and CuO was treated with hydrogen at elevated temperature. CuO was reduced to Cu . (b) Before the experiment, calculate the minimum amount (in mole) of hydrogen required to ensure the reduction is completed. (3 marks) (c) After passing with in excess ...
Thursday, December 22, 2016 by henry39

Science Chemistry
Phosphorous (P) is an indispensable nutrient in food production. According to the estimates, mineral phosphorous resources will end up within 50 years and consequently new sources of P has to be found. A human excretes 2,2 g of phosphorous (P) per day on average. In ...
Thursday, December 22, 2016 by karem

Science Chemistry
according to the reaction below: 4 NO + 3 O2 + 2 H2O → 4 HNO3 a) 0,001 g of NO dissolves into 1 liter of rainwater and all of it transforms into nitric acid. What is the molar concentration of nitric acid in the rainwater? b) Supposing that no other acids are...
Thursday, December 22, 2016 by karem

Science Chemistry
The elementary analysis of 22 g hydrocarbon sample results in 18 g C and 4 g H. a) Choose the correct chemical formula of the hydrocarbon: i) CH4 ii) C2H4 iii) C3H8 b) What is the amount of CO2 in grams formed by the total combustion of hydrocarbon? Assume complete combustion...
Thursday, December 22, 2016 by karem

chemistry
How many grams of aluminum is produced from the decomposition of 34grams of aluminum oxide
Wednesday, December 21, 2016 by Anonymous

Chemistry
If I heated NaNO3, would there be yellow gas inside the test tube?
Wednesday, December 21, 2016 by Sherlique

chemistry
Hi I was wondering if this equation is reversible and be written lime this: NaNO3 + H2O ⇋ NaOH + HNO3 Thanks!
Wednesday, December 21, 2016 by Sherlique

Chemistry
In a reaction Mg(s) + 2HCl(aq) →H2(g) + MgCl2(aq), 6.00 g of Mg was present at 0.00 min. After 3.00 min, 4.50 g of Mg remained. Express the average rate as mol of Mg consumed per minute.
Wednesday, December 21, 2016 by kery

Chemistry
I have asked this question before but I was not clear enough. I want to prepare a 37% w/w solution (in water)of sulfuric acid from 96% sulfuric acid. I need around 500ml, I know it won't be exactly that, I want to know how to use the conversion using density, I've been...
Wednesday, December 21, 2016 by Pam

chemistry
Determine the [OH^-] of a solution that is 0.145 M in CO3^2-.
Wednesday, December 21, 2016 by nurul

Chemistry
The specific heat of silver is 0.24 J/g*C. If 15.4 g of silver absorb 332 J heat, how much will the temperature of the silver increase?
Tuesday, December 20, 2016 by Grace

Chemistry
2CO(g) = 2C(s) + O2(g). A sample of 0.882g of carbon monoxide, CO(g), is completely decomposed in a calorimeter containing 325 g of water. The initial temperature is 17.60*C, and the final temperature is 74.21*C. Calculate the enthalpy change in J/mol of reactant. I hope that...
Tuesday, December 20, 2016 by Madilyne

Chemistry
Given the equation 2SO2(g) +O2(g) -> 2SO3(g), H = -197.8 kJ per Mole, find the quantity of heat transferred when 8.54 grams of sulfur dioxide react completely. I'm stuck. Please help >-<
Tuesday, December 20, 2016 by Madalyn

Chemistry
Hi, I have few questions from a chemistry lab that i did, 1) I'm not sure whats the point of heating a nitrate (NaNO3) 2) I'm not sure why you add NaOH to NaNO3 after it has dissolved in water 3) I'm not sure why do we have to test what gas is produced from calcium...
Tuesday, December 20, 2016 by Sherlique

Chemistry
A 3.4g sample of h2o2 solution containing x% H2O2 by mass requires x ml of a KMnO4 solution for complete oxidation under acidic condition. The molarity of KMnO4 solution is: a)1 b)0.5 c)0.4 d)0.2
Tuesday, December 20, 2016 by Anurima khuranw

Chemistry
how many sulfate ions are in 30 formula units of aluminum sulfate?
Monday, December 19, 2016 by Anonymous

Chemistry
Calculate the work done when 36.0 g of tin dissolves in excess acid at 1.00 atm and 30.1 C.
Monday, December 19, 2016 by Ennaliea

Chemistry
what compound is the result of silver nitrate and potassium bromide
Monday, December 19, 2016 by Alice Keign

Chemistry
What are the products of the neutralization reaction between hydrochloric acid and magnesium hydroxide? a. MgCl and H2O b. MgCl2 and H2O**
Monday, December 19, 2016 by Amberxzx

maths, geography, physics, chemistry
A cuboid has TSA 40 sq. m and latral surface 26 sq. m. Find the base area.
Monday, December 19, 2016 by sneha kaurav

Chemistry
A sample of 76 g of NaCl is dissolved to make 1 L of solution. What is the morality of the solution? How do I get started solving this problem?
Monday, December 19, 2016 by Alice Keign

chemistry
m(ZnO) - ? m (HCl) - ? w(HCl) = 5% m(ZnCl) = 13,64 gram
Monday, December 19, 2016 by yasine

chemistry
CH3-C(triple bond)C-CH-(C2H5)CH3product a and product b
Monday, December 19, 2016 by chemistry

chemistry
CH3-C(triple bond)C-CH-C2H5-CH3product a and product b
Monday, December 19, 2016 by chemistry

chemistry
a gas occupies a volume of 50.0mL at degrees Celsius and 630mmHg.at what temperature in degrees Celsius would the pressure be 101.3kPa if the volume remains constant?
Monday, December 19, 2016 by charles

chemistry
determine d no of moles in d following samples 2.5*10
Monday, December 19, 2016 by promise

Chemistry
A.) Write a balanced chemical Eq'n for a reaction between MAGNESIUM & HYDROCHLORIC ACID. Answer: Magnesium + Hydrochloric Acid Mg (s) + 2 HCL (ag) ---- MgCl2 (aq) H2(g) B.) Assuming 7.00 g of Magnesium completely react according to the above Eq'N, calculate the MOLES ...
Sunday, December 18, 2016 by Jen

chemistry
If 120. g of propane, C3H8, is burned in excess oxygen according to the following equation: C3H8 + 5O2  3CO2 + 4H2O, how many grams of water are formed?
Sunday, December 18, 2016 by vera

Chemistry
What would the step by step process be to perform titration with a strong base and strong acid? Including the equipment. If someone could explain it in a brief way to me that would be appreciated.
Sunday, December 18, 2016 by Gr 11

AP Chemistry!!!
If 5.6 g of aluminum at 65.2 °C is placed in a calorimeter that contains water at 23.5 °C and the temperature of the water after the heat exchange occurs is 24.7 °C, then identify how much water is in the calorimeter. I know this has something ...
Thursday, December 15, 2016 by Callie

Chemistry
A cube of solid reactant with sides of 1.00 cm² is submerged in a liquid and reacts to form a gas product at an initial rate of 20 mL/s. The solid-liquid interface is 6.0cm² of surface area. If you sliced this cube (like a block of cheese) into 10 ...
Thursday, December 15, 2016 by Anonymous

Chemistry
A gas is collected by water displacement at 25 degrees celsius.(the vapor pressure of water at that temperature is 24mmhg.if the atmospheric pressure is 800mmhg.what is pressure of the dry ice
Thursday, December 15, 2016 by Carol

chemistry
PLEASEEEE HELP Write the balanced equation for the reaction between zinc and acetic acid. The equation has been written you just have to balance. ___Zn + ___HC2H3O2 → ___Zn(CH3COO)2 + ___H2
Thursday, December 15, 2016 by Bre

Chemistry
What is the likely identity of a substance (see Table 10-1) if a sample has a mass of 16.0 g when measured in air and an apparent mass of 15.2 g when submerged in water? Which of the following is it? -copper -gold -lead -aluminum -iron or steal -concrete (Note: Can only select...
Thursday, December 15, 2016 by Dominick

chemistry
density of sand =3.00g/cm3?
Wednesday, December 14, 2016 by Anonymous

Chemistry
what happens when magnesium reacts with iodine to make magnesium iodide. Manymanymany thankyou's all round!!!!
Wednesday, December 14, 2016 by moi encore une fois!

Chemistry
what are atoms of nitrogen with different numbers of neutrons called?
Wednesday, December 14, 2016 by plz hlp asap!

Chemistry
what is the acid that is used to make ammonium nitrate???
Wednesday, December 14, 2016 by shannone

chemistry
what are atoms of nitrAogen with different numbers of neutrons called?
Wednesday, December 14, 2016 by Grande

Chemistry
A plasma reaction converts A (Molecular weight = 200) to B and uses NAD as a co-substrate and produces NADH as a by product (1 mole of NADH is produced per every 1 mole of A converted to B). The amount of NADH can be determined by monitoring its’ absorbance ...
Wednesday, December 14, 2016 by Sophia

Chemistry
How much Zn is mixed with 2HCl = ZnCl + H2 ?
Tuesday, December 13, 2016 by Joe

Chemistry
What group of elements were not on the original periodic table
Tuesday, December 13, 2016 by Anonymous

AP Chemistry!!!
Explain the reaction that would occur in a galvanic cell between solutions of Al3+ and Pb2+. Identify the oxidation and reduction reactions and the location of each reaction. Then, use the standard reduction potential tables to determine the cell potential.
Tuesday, December 13, 2016 by Callie

Chemistry
Show calculations (labeled with units) needed to prepare 25 mL of 0.20 M Pb(NO3)2 and 25 mL of 0.20 M NaI.
Tuesday, December 13, 2016 by Jeb

Chemistry (PLZ HELP)
Aluminium can be produced by the thermal decomposition of aluminium oxide. What mass of aluminium would be produced from 3.5kg of aluminium oxide?
Tuesday, December 13, 2016 by Anonymous

Chemistry
Determine the volume of a 0.1 M solution of HCl, necessary to titrate 20 mL of a 0.5 M solution of NH3. The value of Kb is 1.8 x 10-5.
Tuesday, December 13, 2016 by Melanie

Chemistry
Determine the variation of the buffer of the problem 1, if 200 mL of the buffer is added 10 mL of a 1.0 M solution of HCl.
Tuesday, December 13, 2016 by Melanie

Chemistry
Calculate the pH of a buffer made of a 0.4 M of acetic acid and 0.5M of sodium acetate. The Ka for the acetic acid is 1.8 x 10-5.
Tuesday, December 13, 2016 by Melanie

chemistry
1. Silicon dioxide reacts with carbon upon heating to produce silicon carbide (SiC) and carbon monoxide. SiO2(s) + 3C(s) = SiC(s) + 2CO(g) a. What mass of carbon is required to react completely with 15.70 g of SiO2? b. When 152 g of SiO2 reacts with excess carbon, what mass of...
Tuesday, December 13, 2016 by Luke

chemistry
A hydrochloric acid So of concentration 1mol/l and a solution S1 of concentration C1= 2×10^-2 mol/l to be prepared from So. The available materials are given below: ● Volumetric pipet: 5ml, 10ml, 20ml ● Beakers: 100ml, 250ml, ...
Tuesday, December 13, 2016 by angy

physics biology chemistry and ict
WHAT ARE THE ALLOTROPES OF ANTIMONY
Tuesday, December 13, 2016 by SEINI OUSMAN

Chemistry (just need someone to check my answer)
When iron metal reacts with oxygen, the reaction can form Fe2O3. Write a balanced chemical equation for this reaction, and find the number of moles of oxygen that are needed to form 6 mol of Fe2O3. My answer: 9 moles of oxygen
Tuesday, December 13, 2016 by Zoella

chemistry
The first order rate constant for the decomposition of N2O2 of 0Cis 5.2*10/6 per minute. If the activation energy is 6200J/mol, calculate the rate constant at 25C
Tuesday, December 13, 2016 by hadiza

Chemistry
Hello, I was wondering what would happen if u add KOH(potassium hydroxide) solution instead of KOH solid to HCL (hydrochloric acid). Currently, learning enthalpy in class and I'm not sure how this affects enthalpy
Monday, December 12, 2016 by Ann

AP Chemistry
Tungsten(VI) oxide can be reduced to tungsten by heating it with carbo, as shown in the reaction: 2WO3(s) + 3C(s) <---> 2W(s) + 3CO2(g) If the original mass of WO3 is 37.0 g, how many grams of CO2 must be collected from the reaction in order to infer that the solid that ...
Monday, December 12, 2016 by Landon

Chemistry
What is the total ionic and net ionic equation for this aqueous reaction?: Sr(OH)2(aq) + HClO2 (aq) -I wrote the molecular as: Sr(OH)2 (aq) + HClO2 (aq) ---> SrClO2 (aq) + H20 (l) -Is the Total Ionic: Sr2+ (aq) + 2OH- (aq) + H+ (aq) + 2ClO- (aq) ---> Sr2+ (aq) + 2ClO-(aq...
Monday, December 12, 2016 by Les

Chemistry
How many aluminum atoms are there in 15.0mg of Al2O3?
Monday, December 12, 2016 by Les

chemistry
What is the ∆G for the following reaction under standard conditions (T = 298 K) for the formation of NH4NO3(s)?
Monday, December 12, 2016 by abraham

Chemistry
Find the Percentage Composition of 0.68g of CaCO3 in 1.3g of antacid tablet. I think it is 680/1300*=approx. 52%
Monday, December 12, 2016 by Akshay

Chemistry
What is the total number of mole of atoms in 1 mole of Al2(CO3)3?
Monday, December 12, 2016 by Pedro

Chemistry
What is the concentration of Pb in mg/L , if you have 25 mg Pb in 5kg of seawater? (note: density of seawater is 1.025 kg/L)
Monday, December 12, 2016 by Sam

Chemistry
Using the fact that fresh water has a density of 1000 kg/m3 , show that 5ppm Pb = 5 mg/L Pb .
Monday, December 12, 2016 by Sam

Organic Chemistry
Hello! I was looking for some advice on my organic chemistry lab. We were supposed to separate and identify a solid mixed into a liquid. I found and have confirmed my liquid is acetone by distilling it out of the solid. The solid then turned into a whitish powder while in the ...
Monday, December 12, 2016 by Abby

Chemistry
rank the compounds below in order of increasing vapor pressure at 298 K? A) c3h6 B) c4h8 C) c5h10
Monday, December 12, 2016 by Vanessa

Chemistry
If an astronaut weights 804n on earth what would he weight on a planet that has 3 times the mass and twice the radius of earth
Monday, December 12, 2016 by William

Chemistry (percent abundance) *emergency*
If the average atomic mass of Br is 79.90 amu, what is the percent abundance of each of its isotopes? How would we figure out the isotopes first before we calculate the percent abundance??
Monday, December 12, 2016 by Ray

Chemistry
4Fe + 3O2 = 2Fe2O3 158g of Fe will react with how many litres of O2 to produce the maximum amount of Fe2O3
Sunday, December 11, 2016 by Ethan

Chemistry
A 50.0 mL aqueous solution of sodium hydroxide has a pH of 12.50. If 36.00 ml of 0.0200 mol/L sulfuric acid is added to this sodium hydroxide solution, what will be the new pH of the resulting solution? Assume that the temperature stays constant at 25 C, and that the volumes ...
Sunday, December 11, 2016 by Jacob

Chemistry
If 8.87 g of CuNO3 is dissolved in water to make a 0.500 M solution, what is the volume of the solution?
Sunday, December 11, 2016 by Dalton Steele

Chemistry
Why do carbonated beverages go "flat" when opened and left and room temperature and pressure?
Sunday, December 11, 2016 by Anonymous

Chemistry (PLZ HELP)
State why you think clothes might be important to clean in hot water. Is it because it has to do with solubility or something?
Sunday, December 11, 2016 by Anonymous

chemistry
Hydrochloric acid solution reacts with zinc according to the following equation: 2H3O + Zn -> Zn^2+ + H2 +2H2O 100ml of hydrochloric acid solution Ca=0.5mol/l must be prepared from C=5mol/l hydrochloric solution. 1) Specify the glassware needed for this preparation . At ...
Sunday, December 11, 2016 by angy

Chemistry
Draw the Lewis Structure of CH3NCS including all resonance forms. Assign formal charges. Do not include resonance arrows.
Sunday, December 11, 2016 by Raeann

chemistry
What volume of 0.900 M HCl is required to complete neutralize 50.0 ml of a 0.500 M Ba(OH)2 solution?
Sunday, December 11, 2016 by Subiza

Chemistry
This same substance is a gas with a density of 1.25 g/L at 127o C and a pressure of 400 torr. What is its molar mass ?
Sunday, December 11, 2016 by KC

Chemistry
Ammonium nitrate is an oxidizing agent and can give rise to explosive mixtures of mixture of two moles of powdered aluminum and 3 moles of ammonium nitrate crystals react exothermically yielding nitrogen gas water vapor and aluminum oxide how many grams of the mixture are ...
Sunday, December 11, 2016 by Cindy

chemistry
what is the procedure for the preparation of 10 gram of lead iodide
Sunday, December 11, 2016 by kanniga

Chemistry
What is emprical fourmula?
Sunday, December 11, 2016 by Brajesh

Chemistry
A scintillation counter detects radioactivity by: A) none of the answers. B) emission of light from a NaI crystal when radioactivity passes through the crystal. C) ionization of argon gas in a chamber which produces an electrical signal. D) analyzing the mass and velocity of ...
Sunday, December 11, 2016 by Mimi

Chemistry
For the reaction Ag2S(s) ⇌ 2 Ag+ (aq) + S2- (aq), what happens to the equilibrium position if ammonium sulfate is added? A) doubles B) shifts to the left C) does nothing D) shifts to the right E) halves
Saturday, December 10, 2016 by Mimi

chemistry
how many grams of sodium hydroxide is required to neutralize 73grams of hydrochloric acid and to form sodium chloride and water
Saturday, December 10, 2016 by bala

chemistry
The edge of a body-centered-cubic unit cell ( which contains two atoms per unit cell) of an element Y was found to be 2.16x10^-8cm. The density of the metal is 19.35g*cm^-3. What is the approximate molar mass of Y?
Saturday, December 10, 2016 by John

Chemistry
I just need someone to check my answers please :) On the pH scale are the following items base, neutral, or acid? 1. Hand Soap 2. Blood 3. Milk 4. Coffee 5. Orange Juice 6. Soda Pop 7. Vomit 8. Battery Acid My answers: 1. Base 2. Neutral 3. Neutral 4. Neutral 5. Base 6. Acid 7...
Saturday, December 10, 2016 by Zoella

  1. Pages:
  2. <<Prev
  3. 1
  4. 2
  5. 3
  6. 4
  7. 5
  8. 6
  9. 7
  10. 8
  11. 9
  12. 10
  13. 11
  14. 12
  15. 13
  16. 14
  17. 15
  18. Next>>

Homework Help: Science