Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

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 ...

Chemistry
According to kinetic-molecular theory, particles of an ideal gas a) are motionless b) have zero masses c) attract each other d) have negligible volumes

chemistry
100g of water are saturated with KNO3 at 50Ëšc. how many grams of KNO3 will crystallize out if the temperature cools to 40Ëšc? A. 10g B.19g C.64g D.83g

Chemistry
Determine the starting mass of each reactant if 46.3 of K3PO4 is produced and 92.8 of H3PO4 remains unreacted. 3KOH + H3PO4 ----> K3PO4 + 3H2O

Chemistry
Determine the starting mass of each reactant if 46.3 of K3PO4 is produced and 92.8 of H3PO4 remains unreacted. 3KOH + H3PO4 ----> K3PO4 + 3H2O

Chemistry
100g of water are saturated with KNO3 at 50˚c. how many grams of KNO3 will crystallize out if the temperature cools to 40˚c. solubility curve.

chemistry
if 5.76 grams of co2 forms when 4.00 grams of c2h6 reacts, what is the percent yield for 2c2h6+7o2=4co2+6h2o

Chemistry
When a radioactive isotope releases a beta particle, the atomic number of the new element is A. decreased by one. B. decreased by two. C. increased by one. D. increased by two.

chemistry
"What mass of silicon carbide should result when 100.00g of silicon dioxide reacts with excess 100.00g of carbon?" SiO2 + 3 C = 2 CO + SiC (balanced) Direct question from homework; I was wondering if someone could explain how to find the solution with limiting reactants. A ...

Chemistry
Which of the following statements is not true of nuclear fusion? A. It involves the joining of two atoms together into one new atom. B. It occurs in the sun and other stars. C. It only occurs in very large, heavy atoms. D. It releases very large amounts of energy.

Chemistry
Given the following standard reduction potentials in acid solution write the formula of the weakest reducing agent.

Chemistry
How many grams of copper are deposited on the cathode of an electrolytic cell if an electric current of 2.00 A is passed through a solution of CuSO4 for a period of 19.0 min?

Chemistry
When a solution of a certain gadolinium salt is electrolyzed with a current of 1.0 A for 2.0 h, 0.025 mol of Gd metal forms. Calculate the charge on the gadolinium ion in the salt.

Chemistry
How many grams of chromium could be deposited on a bracelet using 0.180 A of electricity for 4.65 hours

Chemistry
How much heat is absorbed when a 35.0 g aluminum block increases in temperature from 23°C to 33°C? Specific heat of Al: 0.900 J*g-1*°C-1 q=msΔT q=(35.0 g)(.900)(33°C - 23°C) q= 315 J? Just making sure there isn't anything that I am missing.

Science
In what fields would a lab technician need to separate & identify organic items? I looked it up and it said organic chemistry, forensics.. . I'm not which one because couldn't it range?

Chemistry
Which response presents ions in order of increasing atomic radius? a) smallest Cl-, K+, Na+ largest b) smallest Cl-, Na+, K+ largest c) smallest K+, Na+, Cl- largest d) smallest Na+, K+, Cl- largest I would assume the answer would be D since the electrons are more tightly ...

Chemistry
Which of the changes are chemical changes? a) Sugar crystals are ground to a fine powder. b) A candle is burned c) Two clear colorless salt solutions are mixed and a bright orange precipitate forms. d) Candle wax is melted e) A silver teapot turns black

chemistry
Are these physical property's of a pure compound? What are physical properts off this list???? molar weight reactivity with halogens volatility melting and boiling points hardness, brittleness odor density air sensitivity flammability radioactivity colour toxicity chemical ...

Chemistry
After balancing the following redox equation(using small whole-number coefficients), add the coefficients of all species in the balanced equation. Bi(OH)3 + SnO2^(2-) → Bi + SnO3^(2-) (basic solution) --- I separated the equation into two and i know the next step is to ...

chemistry
When the equation: Al(s) + HSO4-(aq) + OH-(aq) → Al2O3(s) + S2-(aq) + H2O(l) is balanced with smallest whole number coefficients, the coefficient for the hydrogen sulfate ion will be ______.

Chemistry
What volume of 0.200 M K2C2O4 is required to completely react with 30.0 mL of 0.100 M Fe(NO3)3? 2Fe(NO3)3 + 3K2C2O4 --> Fe2(C2O4)3 + 6KNO3

Chemistry
Which electron transition in a hydrogen atom will emit a photon with the longest wavelength? n = 2 to n = 1 n = 3 to n = 1 n = 1 to n = 2 n = 1 to n = 3 I would assume it would be a short electron transition since energy and wavelength are inversely related. But I am a little ...

Chemistry
Calculate the mole fraction of ethanol in 95% by mass aqueous solution.Mol. mass of ethanol is 46.

Chemistry
Which element is oxidized and which element is reduced in this redox reaction? CO2(g) + H2(g) --> 2CO2(g) + H2O(g) Is Oxygen oxidized and hydrogen reduced?

Chemistry
What is the net ionic equation form the reaction between Na2S(aq) and Pb(HCO3)2(aq)? Just wanting to make sure this correct: 2Na+(aq) + S2-(aq) + Pb2+(aq) + 2HCO3-(aq) --> 2Na+(aq) + 2HCO3-(aq) + PbS(s)

Chemistry
What mass of NO2 is formed by the complete reaction of 2 mol O3 with excess NO in the reaction? O3 + NO --> O2 + NO2 I know the molar mass of O3 is 48 g/mol and NO2 46 g/mol a) 23.0 g b) 46.0 g c) 92.0 g d) 96.0 g

Chemistry
What is the empirical formula for a compound of sodium and oxygen that contains 59% by mass? I am guessing it would be NaO because the molar mass of Na is 22.99 g/mol and 22.99 g/mol Na / 22.99 + 16 is approx 59%. Just wanted to make sure that is correct.

Chemistry
A 10.000 g sample of water contains 11.19% H by mass. What would by the %H in a 20.000 g sample of water? I got 22.38%, would that be correct?

Chemistry
Which compound has the highest lattice energy? a) CaO b) LiF c) MgO d) NaF I am guessing B because Lithium has the lowest energy level?

Chemistry
An unknown metal, m, forms an ionic compound with the formula, M2S3. Which formula represents the compound formed by the metal with oxygen? a) MO b) MO2 c) MO3 d) M2O3

Chemistry
HI is formed from the overlap of a hydrogen 1s orbital with an iodine 3p orbital? is that correct? I am having trouble with the iodine orbital, thank you.

Chemistry
The solvent CCl4 is manufactured as follows CS2+Cl2=CCl4+S2Cl2. Balance it and calculate the grams of CS2 needed to react with 62.7 of Cl2?

Chemistry
The radius of a single atom of a generic element X is 199 picometers (pm) and a crystal of X has a unit cell that is face-centered cubic. Calculate the volume of the unit cell.

Chemistry
A farmer wants to capitalize on the amount of sunlight shining on his farm everyday by building a solar power tower. The manufacturer\'s specifications state that the solar tower has 5.0 × 101 heliostats, each with an area of 2.10 m2. If the total amount of solar power ...

Chemistry
is H2CO3+2LiOH=Li2CO3+2H2O a oxidation reduction reaction??

Chemistry 212
The isotope californium-252 has a half life of 162 days. How many days would it take for 61.7% of the original material to decay? I am using the equation t= (ln(nt/no))/ k and I am first solving for K using: k=(.693/t1/2) the suppose answer can range from (10.7-10.9) but Im ...

chemistry
A chemistry student weighs out 0.0294g of sulfurous acid H2SO3 , a diprotic acid, into a 250.mL volumetric flask and dilutes to the mark with distilled water. He plans to titrate the acid with 0.2000M NaOH solution.

chemistry
A chemist must dilute 55.5mL of 2.80 M aqueous nickel(II) chloride NiCl2 solution until the concentration falls to 2.00 M . He'll do this by adding distilled water to the solution until it reaches a certain final volume.

chemistry
if 2 atoms combined their 4f orbitals, what type of orbitals should form?

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Homework Help: Science