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Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

chemistry
What volume of H2 is produced if excess nitric acid (HNO3) reacts with 46.3 g of magnesium 2HNO3 + Mg → H2 + Mg(NO3)2

Chemistry
If the back of your hand is moistened with alcohol, you will find that it rapidly becomes dry ,But if we do so with water it does not get dryer rapidly . Why?

Science/chemistry
CH4 + 2O2 --> OC2 + 2H2O What mass of water is formed by burning 4g of methane in excess oxygen? (Ar of carbon=12, Ar of oxygen=16 and Ar of hydrogen=1)

Chemistry
Methane (CH4) behaves as an ideal gas under standard temperature and pressure conditions. What volume is occupied by 1 kg of methane at a temperature of 35 °C and a pressure of 0.9 atm?

Chemistry
I know I am over thinking this problem like always but none of this makes sense to me for some reason.. KHP was used to determine the concentration of a KOH solution. If 0.78g of KHPwas used and 42.17 ml of KOH was used to titrate it to the endpoint what's it concentration? ...

chemistry
What's the aim of titrating potassium tetraoxomaganate(vii) with ammonium iron (ii) tetraoxosulphate (vi)

chemistry- morality
To what volume should 1.19 ml of an 8.00 m acetic acid solution be diluted in order to obtain a final solution that is 1.50 M? show all work

chemistry
Question : ka1 and ka2 values of H2X is given 1*(10)^-5 M and 1*(10)^-9 M.50cm^3 of 0.2 M KOH and 50 cm^3 of H2X of unknown concentration is mixed together and the pH of the final solution is given as 7. 1)Find the concentration of H2X 2)Find the pH of the initial H2X solution...

Chemistry
How many milliliters of a 5.15 M stock solution are needed to prepare 375 mL of a solution having 7.50 mg of methanol per mL of solution?

Chemistry
Question : ka1 and ka2 values of H2X is given 1*(10)^-5 M and 1*(10)^-9 M.50cm^3 of 0.2 M KOH and 50 cm^3 of H2X of unknown concentration is mixed together and the pH of the final solution is given as 7. 1)Find the concentration of H2X 2)Find the pH of the initial H2X solution...

Chemistry
What volume of a 0.500 M NaOH solution is needed to neutralize 60.0 mL of 0.15 M HCl solution?

chemistry
What will happen if ammonium chloride solution is used to standardize the potassium tetraoxomangate(vii)solution?

Chemistry
When 25.3 mL of 0.100 M NaOH was reacted with 18.8 mL of H2SO4 of unknown molarity, the final solution was 0.029207 M in H2SO4. What is the molarity of the original H2SO4 solution? The equation for the reaction is: 2 NaOH + H2SO4 → Na2SO4 + 2 H2O

Chemistry
Would glacial ethanoic acid have (l) or (aq) state symbol? I'm thinking liquid as it doesn't contain any water but would just like to confirm as struggling to find any equations involving it online? Thank you :)

Chemistry
The density of aluminum is 2.70 g/ml. What is the mass of a cube of Al that measures 2.20 cm on each side?(remember significant figures and to include the units of g in your answer, remember that 1 ml=1 cm3) Need help can someone go step by step so I can understand how to do it

chemistry (science)
explain the observed temperature change upon mixing ethanol and cyclohexane.

Chemistry
A solution is made by dissolving 10.20 grams of glucose (C6H12O6) in 355 grams of water. What is the freezing point depression of the solvent if the freezing point constant is -1.86 °C/m?

Chemistry
A substance has a molecular formula of C8H10N4O2. The empirical formula is -

Chemistry
If a 500ml brine is electrolysed with current of strength 0.5A,how many seconds would it take to achieve natural point

Chemistry
The electrolysis of 250ml of a brine solution was carried out for a period of 20mins with a current of 2A. The resulting solution was titrated with 0.62M HCL. How many ml of HCL would be required to achieve natural point

chemistry
Now use the average value of Kb the base dissociation constant of acetate anion to calculate an average value for Ka, the acid dissociation constant of acetic acid. Kb: 1.33x10^-10

Chemistry
Oxidation Numbers: My question to you is how did Al get a +3 Oxid.#, and S got 6... What is the mathematical explanation for that. I understand the rules that O is almost always -2 for its' oxid #. Would O be 10 bc you'd multple 4*3 and minus 2?

Chemistry - Significant Figures
Suppose it takes 35 min for 2.4 g of sugar to completely react with another reagent we added to the flask. What would the reaction rate be? Calculate to the correct number of significant figures.

chemistry
showing your work convert R=0.08206 atm dm^3 mol^-1 k^-1 to jmol^-1 k^-1

chemistry
explain why benzoic acid do not affect litmus paper

chemistry under gas law
convert the following. R=0.08206atm dm^3 mol^-1 k^-1 to jmol^-1 k^-1

chemistry ( little urgent pls)
For oxidation of iron 4Fe+3O2=2Fe2O3 the entropy change is -549.45JK^-1mol^-1 at 298K. Though it has negative entropy change in the reaction is spotaneous.why? (Delta r H theta ∆rH°=-1648×10^3 J ml^-1. Is it because ∆G is negative????

chemistry
If the pressure, volume, and temperature of a gas are known, which can most likely be found by using the ideal gas law?

Chemistry
Can anybody understand me about oxidising agent and reducing agent

erectlo chemistry
ADDIS ABABA UNIVERSITY ADDIS ABABA INSTITUTE OF TECHNOLOGY SCHOOL OF CHEMICAL AND BIO ENGINEERING Applied Electrochemistry WORKSHEET -1 1. Calculate the standard potential of each of the following cells. State which one(s), if any, will proceed spontaneously as written. a. Sn...

Organic chemistry lab
In the synthesis of salicylic acid from wintergreen oil, 5 ml of 20% NaOH was used, can it be used more or less than this amount?

chemistry
in which solvent is best suited to dissolve non-polar substances, water,ethanol or hexane

chemistry
In general which type of solvent is best suited to dissolve ionic or highly polar substances

Chemistry
I get that you're supposed to balance; however, I was confused on how to do the reduction and oxidation electron equations (the simplist way). Looked at too many examples online but nothing was clear. 1) Cu + HNO3 → Cu(NO3)2 + NO2 + H2O 2.) KMnO4 + H2SO4 + FeSO4 → MnSO4 + ...

chemistry
40 mL of 0.150 M ammonium hydroxide is added to 20 mL of 0.3 M perchloric acid. What is the final pH of the resulting solution?

chemistry
30.0 mL 0.200 M lithium hydroxide is added to 50 mL of 0.1 M nitrous acid. What is the final pH of the resulting solution?

Chemistry
30.0 mL 0.200 M lithium hydroxide is added to 50 mL of 0.1 M nitrous acid. What is the final pH of the resulting solution?

chemistry
what is something that would lower the freezing point of water to -3.7 degrees c if one mole were placed in 1000 g of water? I don't understand how to do this question, I'd appreciate the help (: Thank you

Chemistry
Write the oxidation and reduction half-reactions for a silver-chromium voltaic cell. (Use the lowest possible coefficients. Include states-of-matter at 1 atm and 25°C in your answer.)

Chemistry
If four amino acids are all different, what is the number of peptides possible? A) 2 B) 4 C) 8 D) 10 E) 12 F) 24***

chemistry
What would a substance that boils at 70 degrees celsius at 30 kPa be? I'm really not sure on how to find this.

Chemistry
The nitrogen-containing bases in RNA have the abbreviations ____________________. A) A, G, C, U*** B) A, G, T C) A, G, U D) A, G, C, T E) A, G, T, U F) A, G, U, T

chemistry 20
Lab: Determining the Quantity of Vitamin C in Fruit Juice Vitamin C, also called ascorbic acid, is commonly found in commercial fruit juices and drinks. In this activity you will analyze data collected from a titration analysis of a fruit juice. The nutrition facts for a 200-...

Chemistry
Calculate the percentage of acetic acid used in 2.1g of acetic acid that was titrated against 0.1M NaOH

Chemistry
Calcium Chloride reacts with sodium carbonate (aq) to form solid calcium carbonate and aqueous sodium chloride. Determine the volume of a 2.00M Calcium chloride solution that would be needed to exactly react with 0.0750L of 1.00M sodium carbonate. (Use BCA table)

Chemistry
Concentrated HCl is 12.0M(mol/L) and you want to make a liter of 1.00 M HCl. What volume would you need of this concentrated solution so you would have one mole of HCl?

chemistry
How would you write the chemical equation for sodium nitrate + isopropyl alcohol. So it would be NANO3 (aq) + C3H8O (aq) -> But I'm not sure how to find the products, thanks for your help!

Chemistry
A solution has a hydrogen ion (or hydronium) concentration of 3.16 X 10-8 M. What is the pH of the solution? 7.5 8.5 <my choice 8.0 7.0

Chemistry
Which of the following is a weak base? ammonia ethyl alcohol vinegar potassium hydroxide <my choice

chemistry
A solution. Of glucose was prepared by dissolving certain amount in 100 grams of water ,the depression in freezing point is. 0.041kelvin if depression of water is 1.86 kelvin*kg/mol.calculate the weight of glucose dissolved .

chemistry(buffer solutions)
Calculate the pH of the buffer solution that would be ormed by mixing 500cm3 of 0.1mol/dm3(aq)ammonia with 500cm3 off 0.1mol/dm3(aq)ammonia chloride.

Chemistry
The vapor pressure of pure methanol at 25 degrees Celsius is 127.2 mm Hg. If 12.20 g of potassium chloride are dissolved in 200.0 g of methanol, what is the vapor pressure of the solution? A.123.9 mmHg B.3.256 mmHg C.104.3 mmHg D142.7 mmHg

Chemistry
What mass of potassium nitrate would you have in order to produce 1.00dm of oxygen at rtp?

chemistry--------help please!!!!
Which of the following is the strongest reducing agent? Ca2+(aq) Li+(aq) Ca(s) Na(s) K(s) ans: K(s) but I don't understand why it is. I think that li+ is strongest reducing agent b/c E of Li=-3.04 while E of K is -2.92. can someone help me?

chemistry
At 10 degrees C a cannon fires a shell at 1324m/s a) how fast is the shell traveling relative to the soundwave of the explosion? b) how far away from the cannon is the observer how sees the shell pass by 2s before the sound of the explosion arrives? I don't understand a and I ...

Chemistry
For the reaction CH3COOH- CH3COO + H+, which of the following statements is true? CH3COO- is an Arrhenius base. CH3COO- is a conjugate CH3COOH- is a Brønsted-Lowry acid. <my choice CH3COOH- is a Brønsted-Lowry base.

chemistry ( little urgent pls)
PQ and RS are two sparingly soluble salts.Their solubility products are equal to 4.0×10^(-18). Which salt is more soluble

Chemistry
Which of the following would has a -1/3 charge? down quark <my answer hadron up quark electron

college chemistry!!!
Calculate the pH of 500ml 0.07M nitrous acid solution to which 1.4015 grams of sodium nitrite (KW=68.9953) are added.

chemistry
A sample of 2.50 g LiI is added to 75.0 mL of water initially at 21.0°C. After stirring and dissolving, the temperature of the solution is 24.3°C. Assume that the specific heat of the solution is 4.184 J/g°C, the density is 1.00 g/mL, and the calorimeter constant is 40.0 J...

chemistry
calculate the molarity of sodium carbonate in a solution prepared by dissolving 5.9g in enough water to form 250ml of solution

chemistry
a 215 ml sample of ocean water contains 7.1g. what is the molarity of nacl

Chemistry
Explain how the entropy and enthalpy values ( + or -) can be used to explain the spontaneous or nonspontaneous solvation of different salts. I know that the if the entropy value is higher the more spontaneous the process is but don't know why. And I don't know how to answer ...

chemistry
What is something that would lower the freezing point of water to -3.7 degrees C if one mole were placed in 1000g of water? I'm not sure how to go about this, I appreciate your help. (:

Chemistry
A sample of 2.50 g LiI is added to 75.0 mL of water initially at 21.0°C. After stirring and dissolving, the temperature of the solution is 24.3°C. Assume that the specific heat of the solution is 4.184 J/g°C, the density is 1.00 g/mL, and the calorimeter constant is 40.0 J...

chemistry
What is a liquid that is known for its high viscosiy due to H bonds? (not water) I'm not sure how to find this, I feel like it should be easy to just google but I really can't find anything about it. I'd appreciate your help, thank you!

chemistry
calculate the molarity of sodium carbonate in a solution prepared by dissolving 5.3g in enough water to form 250ml of solution

College Chemistry!!
Calculate the relative concentration of phenol (ka=1.05x10^10) and phenolate ion in a solution with 0.05M total phenol (pH=7.5)

chemistry
the half life radium-222 is 4 days. if a sample of radon-222 undergoes decay for 12 days, how much of the original parent isotope will be left?

chemistry
calculate the molarity of sodium carbonate in a solution prepared by dissolving 5.3g in enough water to form 250ml of solution

chemistry
If the students added hcl instead of tetraoxosulphate(Vi)acid

chemistry
So the question I have is: Calculate the pressure of dry hydrogen collected. (Use the water temperature). And the evidence that we obtained was: Length of magnesium 3.8Cm Mass of 1 m of magnesium 1.254g Volume of hydrogen collected 67mL Air temperature 27C Water temperature ...

science
A mixture of benzenoic acid aniline and phenol is dissolved in chroloform and the solution was treated with sodium hydroxide.hydrochloric acid and sodium bicarbonate.show the separation chart,identify the composition of each phase and explain the chemistry of the separatiob ...

Chemistry
Which of the following distinguishes a nuclear reaction from a chemical reaction? Mass is conserved. It involves atoms. There is an exchange of electrons. <my answer There is a change in the nucleus.

CHEMISTRY.
Calculate the ph of a solution containing 0.15M HF (ka= 7.1x10^-4) and 0.26M NaF.

Chemistry
How many lone pairs does Cl- have? I can draw it using a cross and dot diagram but not sure if it would have 4, or 3 as one of the electrons has been added from somewhere to make it an ion? Thank you!

Chemistry
What are the changes associated with a chemical reaction?

AP Chemistry
Hi I need help on this bonus question my teacher gave out it's reducing/oxidation equation in an acidic solution. Cr(NCS)6-4 (aq) + Ce+4(aq) ----------> Cr+3(aq) + Ce+3(aq) + NO3-1(aq) + CO2(g) + SO4-2 (aq)

Chemistry
I need help balancing this acidic equation out with reduc/oxidation. Mn+2 (aq) + NaBiO3(s) -----> Bi+3(aq) + MnO4-1(aq)

Chemistry
A DNA template having the base sequence A-G-A-T-G-A would produce a mRNA with a base sequence of ______. A) A-G-A-T-G-A B) U-C-U-A-C-U D) T-C-T-U-C-T E) T-C-T-A-C-A F) A-C-A-U-C-A*** G) T-C-T-G-C-T

chemistry
Initially you have 204 g grams of solid thallium at is at its melting point of 304ºC . How many grams of liquid thallium will be present after 476 joules of heat have been added. specific heat liquid thallium is 0.13j/g ºC; heat fusion = 21 j/g; boiling point thallium is ...

chemistry
How many grams of ammonia are produced when 32g of nitrogen react with excess hydrogen? N2 + 3H2 --> 2NH3

Chemistry
calculate the delta G^o and Kc for the reaction: 2Al + 3I2 = 2Al^3+ + 6I-

Chemistry
Given that HSO4- is a stronger acid than HPO4^2-, what is the chemical reaction if solutions containing these ions are mixed together? (Hints: One of these must act as an acid and the other as a base. Use the Brønsted-Lowry definition) Please explain how to get the answer. ...

Chemistry
The delta G^o for a reaction : h2 (g) + i2 (g) = 2HI(g) Is 2.6 kj/moles. In one experiment the initial pressures are P h2 = 4.26 atm, P i2 = 0.024 atm, P hi = 0.23 atm. Calculate delta G

Chemistry
The delta G^o for a reaction : h2 (g) + i2 (g) = 2HI(g) Is 2.6 kj/moles. In one experiment the initial pressures are P h2 = 4.26 atm, P i2 = 0.024 atm,

Chemistry
So this is a three part question. I solved the first part correctly but I need help with the second and third. Q: The dissociation equilibrium constants for the protonated form of of alanine (a diprotic amino acid, H2X+)are Ka1 = 4.6 x 10^-3 and Ka2 = 2.0 x 10^-10. Assume that...

Chemistry
Initially a 1 L vessel contains 10 moles of NO2 and 6 moles of O2. At equilibrium, the vessel contains 8.8 moles of NO2. Determine Kc. Please help

Chemistry ASAP
Protons and neutrons are made from which of the following particles? up quarks only up quarks and down quarks <my choice down quarks only hadrons

Chemistry
Protons and neutrons are made from which of the following particles? up quarks only up quarks and down quarks <my choice down quarks only hadrons

Chemistry
A rock contains 270 mmol of 238 U (t1/2= 4.5*10^9 yr) and 110 mmol of 206 Pb. Assuming that all the 206 Pb comes from decay of the 238 U, estimate the rock’s age.

chemistry
Sorry this is the last question i have select from the words below the effect of a catalyst on each of the following. (Words can be used more than once or not at all). Words: Increase, decrease, changes, doesn't change activation energy reaction mechanism enthalpy of reaction ...

Chemistry
to prepare 50.0 g of 10% NaNo3 solution you will need how many grams of solute

Chemistry
to prepare 50.0 g of 10% NaNo3 solution you will need how many grams of solute? i am having trouble settin these solutions equations up

Chemistry
A container at room temperature is filled with equal moles of O2(g), NO2(g) and He(g). The gases slowly leak through a pinhole in the container. After some gas has effused, which relationship is true about the partial pressures of the gas remaining in the container? a) P He &...

Chemistry
What is the process to calculate ΔH° for the reaction? O2(g) + 2NO(g) --> N2O4(g) O2(g) + 2NO(g) --> 2NO2(g) ΔH°1 N2O4(g) --> 2NO2(g) ΔH°2 a) ΔH°1 + ΔH°2 b) ΔH°1 - ΔH°2 c) ΔH°2 - ΔH°1 d) ΔH°1 - 2ΔH°2 I know according to Hess' Law that I need to ...

Chemistry
Use the 1/2 reaction method to balance the equation below in acidic solution. Cl2 (g) + I- (aq) = Cl- (aq) + IO3- (aq)

Chemistry
Determine the hydronium ion concentration in a solution that is 0.00042M HCL Answer in units of M.

Chemistry
C (s) + S2 (g) = CS2 (g) . Kp=5.6 At equilibrium, P cs2 = 0.152 atm. Find P s2 How would I start this problem?

chemistry
The rate law is : rate = k [NO2]^2. Write an equation for the overall reaction. Identify the intermediate. Which elementary reaction is the slow one? I've been looking in my book on how to do this but I can't find how. Also, could you please explain the steps to me? I have a ...

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