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Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

college chemistry
if 75 g of ice at 0.0 degrees C were added to 1.5 L of water at 75 degrees C what would be the final temperature of the mixture

chemistry
Upon heating 125g MgSO4 • 7 H2O: a) how many grams of water can be obtained?

chemistry
45.3 m + 12.344 m + 1000m - 1.34 m = ________________________ is 1 056.304 m the answer?

chemistry
I got the molecular formula is NaHCO3+H2SO4=Na2SO4+CO2+H2CO3 and i got the total ionic formula is NaOH+H2CO2(aq)= Na2CO3 + HOH but i am having trouble finding the net ionic formula can you please help me thank you

chemistry
1. 35cm + 8.3m + 75.341 km + 80,000 mm = ____________ 2.(43.7m + 39.3cm) ÷ 25.332 m/s = _____________ * focus on significant figures

Chemistry
A sample of 8 grams of NaOH is dissolved into 599 mL of aqueous 0.250 M NaOH (assume no volume change). This solution is then poured into 1.68 gallons of water. (You may assume that the two volumes can be added.) What is the concentration of NaOH in the final solution? ...

chemistry
convert : 1. 25.25 cm to Tm: 2. 1 zm to Zm: 3. 25 m3 to cL: 4. 1.23 x 10^4 L to m3: 5. 1000 cm3 to L: 6. 8,000,000 km to nm:

chemistry
Light travels at 3.00 x 10^8 m/s. If the starlight from the Unicorn galaxy takes 1 year 47 days and 2 hours to reach us. How far away is it in kilometers?

Chemistry
if you dissolve 25.5 g of KBr in enough water to make 1.75 L of solution, what is the molarity of the solution

Chemistry
Calculate the volume of NaOH 0.5 mol/L necessary to neutralize 300 mL of HCl 0.2 M. na= how do I calculate this? Ma= 0.2 M Va= 0.300 L nb= 0.5 mol Mb= 0.5 M Vb= ?

Chemistry
What kind of compound is table salt and how does it dissolve in water? Would salt dissolve in vegetable oil? Why or Why not?

chemistry
what is the final temperature of amixture containning 25 grams of ice at -20 degree celciusadded to water at room temperature 22oC mass of water is 50g followed the steps given by you but not getting the answer (0degree celsius) ice at -20 to ice at 0 degree=mcdelta T=25*2.06*...

Chemistry
Predict which compound will have the higher boiling point and explain how you made your choice by including intermolecular forces. 1. H2O or CH2O 2. CS2 or CH4

chemistry
what is the final temperature of amixture containning 25 grams of ice at -20 degree celciusadded to water at room temperature 22oC mass of water is 50g followed the steps given by you but not getting the answer (0degree celsius) ice at -20 to ice at 0 degree=mcdelta T=25*2.06*...

chemistry
what is the final temperature of amixture containning 25 grams of ice at -20 degree celciusadded to water at room temperature 22oC mass of water is 50g followed the steps given by you but not getting the answer (0degree celsius)

Chemistry
Consider a chromium-silver voltaic cell that is constructed such that one half-cell consists of the chromium, Cr, electrode immersed in a Cr(NO3)3 solution, and the other half-cell consists of the silver, Ag, electrode immersed in a AgNO3 solution. The two electrodes are ...

Chemistry
Suppose a patient is given 140mg of I−131, a beta emitter with a half-life of 8.0 days. Assuming that none of the I−131 is eliminated from the person's body in the first 4.0 hours of treatment, what is the exposure (in Ci) during those first four hours? Express ...

Chemistry
Calculate ΔG∘ at 298 K for the following reactions. A) Ca(s)+CO2(g)+12O2(g)→CaCO3(s) B) 2KClO3(s)→2KCl(s)+3O2(g) C) CO(g)+H2O(g)→H2(g)+CO2(g)

Chemistry
Consider the following reaction: CaCO3(s)→CaO(s)+CO2(g). Estimate ΔG∘ for this reaction at each of the following temperatures. (Assume that ΔH∘ and ΔS∘ do not change too much within the given temperature range.) A) 310K and is it ...

chemistry
a piece of iron measures 10.5cm by 5.25cm by 10.2mm and the density of theiron is 7.86g/cm cubed. what is the mass of the iron?

science
can u suggest 5 advantages and 5 disadvantages of diffusion in chemistry

chemistry
An ideal solution of 5.00 mole benzene and 3.25 mole toluene. At 298 K, the vapor pressure of the pure benzene and toluene were 96. Torr, and 28.9 Torr, respectively. At what pressure does the vapor phase appear first, if the pressure above this solution is reduced from 760 ...

chemistry
preparation of N/10 NaoH

chemistry
Radioactive decay is a process that follows first-order kinetics. The half-life of 32P is 0.03920 years; how long (in minutes) would it take for the amount of 32P to decrease to 53.25% of its initial amount? I don't understand at all what to do here

Chemistry 104
The pH of 0.3 HSO3- is: (How can this problem be solved?) The final answer is 4.41 However, I keep getting 3.76

Chemistry Who step by step
A 0.8870g sample of a mixture of nacl and nan03 is dissolved in water, and the solution is then treated with an excess of AGN03 to yield 1.913g of agcl. Calculate the percent by mass of the nacl in the mixture. 1.913g / 143 = 0.0133 x/58 ( 0.8870g -x) y/85 = 0.0133 0.01529 - 0...

chemistry
Answer the following math questions focusing on significant figures a. 45.3L x 10 mol/L = b. 67.894 g ÷ 2.56 L = c. 45.3m + 12.344m + 1000m – 1.34m = d. 35cm + 8.3m + 75.341 km + 80,000 mm = e. (43.7m + 39.3cm) ÷ 25.332 m/s =

chemistry
how many significant figures do the following numbers have? a. 1.2056 x 10^4 m: b. 1 x 10^89 km: c. 12,000 L: d. 0.000345 cm: e. 1.00036 mL: f. 0.2056000 m:

(2-8) Chemistry - Science (Dr. Bob222)
Which of the following statements is correct? A) The internal energy of a system increases when more work is done by the system than the heat that flows into the system. B) The system does work on the surroundings when an ideal gas expands against a constant external pressure...

Chemistry
if you produce 5.7 of H2O, how many liters of O2 will be required?

Chemistry
How can I determine the overall electrochemical reaction that proceeds spontaneously? Cd2+ | Cd, Co2+ | Co 1. Cd+Co2+ −¨Cd2++Co 2. Co+Cd2+ −¨Co2++Cd (1. and 2. are answer choices)

Chemistry
Given the Na+/Na and K+/K half-cells, determine the overall electrochemical reaction that proceeds spontaneously and the E0 value. Answer in units of V Can you please explain the steps?

chemistry
What is the energy released when steam at 25 g of steam at 10 degree celcius is cooled to ice at-10 degree celcius work heat change for the following changes calculated 150 degree Celsius steam --150 degree water 150 degree water to 0 degree water 100 degreewater-- 0 degree ...

Chemistry help
I am not to sure how to approach the problem... Hydrazine is used as a rocket fuel because its reaction with oxygen is extremely exothermic: N2H4(liquid) + O2(g) ==> N2(g) + 2H2O(liquid) ΔH(reaction) = -615 kJ mol-1 What is the enthalpy of this reaction if water were ...

chemistry
A solution is made by dissolving 811.0 cg of barium hydroxide, Ba(OH)2, in 0.1137 kg of water. What is the concentration in parts per million? I know the equation is: ppm= (mass of solute/mass of solution)10^6 Does the mass need to be in g or kg?

chemistry
Consider the following system, which is at equilibrium, 3C(s) + 3 H2(g) mc020-1.jpg CH4(g) + C2H2(g) The result of removing some C(s) from the system is that a) more CH4(g) and C2H2(g) are produced to replace that which is removed. b) Kc decreases. c) more C(s) is produced. d...

chemistry, first year university
Solid NH4N3 decomposes explosively according to the following equation: NH4N3(s) ⇌ 2N2(g) + 2H2(g) A small amount of ammonium azide was placed in a sealed container and the air was removed. The sample was then detonated. At equilibrium the total pressure in the container...

chemistry
Write equations for the ionisation in water of : A) hydrobromic acid B) nitrous acid C) carbonic acid D) sulfuric acid

chemistry
Why is it recommended to carry out iodometric titration as quickly as positive and to get the first end point?

chemistry
Match the name or structure with its functional group. Each molecule has only one functional group. My choices are alkane, alcohol, alkyne, carboxylic acid, alkene, aldehyde, ketone, ester, and ether. 1. 2-propanol- alcohol 2. 2-methoxypentane- alkane 3. formaldehyde- aldehyde...

Chemistry
During an acid-base titration, 25 mL of NaOH 0.2 M were required to neutralize 20 mL of HCl. Calculate the pH of the solution for each: a) Before titration b) After adding 24.9 mL of NaOH c) At equivalence pt d) After adding 25. 1 mL of NaOH e) The pH of the equivalence pt ...

Chemistry - Science (Dr. Bob222)
Liquid chloroform (CHCl3) is placed in a closed container and allowed to equilibrate with chloroform vapor. With the temperature held constant, additional chloroform is introduced into the system, and the vapor-liquid equilibrium is reestablished. Following this, the ...

Chemistry
How would you write these chemical reactions?Can someone do one or two reactions for each problem, so I could get an idea of to them? ..I'm nit sure how most of the oeoducts wouls turn out..especially if it is a precipitate. 5. When Mn^2+ ions are separated from the mixture, ...

Chemistry
Please explain how to set this problem: A solution has a density of 1.73 g/ml. If it's weighs 4.3 ounces, what is the volume. ?

chemistry
This functional group can be generated by oxidation of an aldehyde. Oxidation is just the reaction with oxygen, but unlike combustion you are not producing carbon dioxide and water.

chemistry
One kind of battery used in watches contains mercury(II) oxide. As current flows, the mercury(II) oxide is reduced to mercury. HgO(s) + H2O( ) + 2 e–  Hg( ) + 2 OH–(aq) If 2.3  10–5 amperes flows continuously for 1200 days, what mass of Hg( ) is produced...

chemistry
This type of functional group is often sweet smelling and may be used as a fragrance. When it reacts with water it will produce a carboxylic acid and an alcohol. I chose ester but it is wrong

Organic Chemistry
A student obtains a yield of 79% from his salicylic acid. How many grams of salicylic acid will the student need to produce 135 g of aspirin?

(1-22)Chemistry - Science
Consider the following reaction: C(s) + H2O (g) ⇌ CO (g) + H2 (g) (Kp = 0.45 at 900 K) What is the equilibrium partial pressure of H2O when the initial partial pressure of water is 1.00 atm? a) 0.43 atm b) 0.58 atm c) 0.22 atm d) 0.52 atm e) 1.16 atm

(1-17)Chemistry - Science
Consider the reaction: SO2 (g) + NO2 (g)  SO3 (g) + NO (g) At T = 1000 K, where the reaction is exothermic with an equilibrium constant K = 9.00 If the reaction vessel is instead charged initially with SO3(g) and NO(g), each at a partial pressure of 0.500 atm, the ...

(1-16)Chemistry - Science
Consider the reaction: SO2 (g) + NO2 (g) ==> SO3 (g) + NO (g) At T = 1000 K, where the reaction is exothermic with an equilibrium constant K = 9.00 The reaction vessel is charged initially with all four gases, each at a pressure of 0.5 atm. After equilibrium is achieved, ...

(1-15) Chemistry - Science
Assume a gas of molecular mass M g/molecule obeys the Maxwell Boltzmann distribution of speeds at temperature T. If u2> u1, the ratio of the number of molecules at speed u2 to the number at speed u1 a) is always less than one. b) is always greater than one. c) can be either...

(1-13) Chemistry - Science
Which of the following effects will make the ratio (PV) / (nRT) less than 1 for a real gas? a) The gas molecules are large enough to occupy a substantial amount of space. b) A large number of molecules have speeds greater than the average speed. c) The gas molecules have a ...

1-12. Chemistry - Science
At STP, 3.0 L of D2 reacts completely with 3.0 L of E, producing 1.5 L of a product. What is the formula of the product?

(1-11) Chemistry - Science (Dr. Bob222)
Liquid chloroform (CHCl3) is placed in a closed container and allowed to equilibrate with chloroform vapor. With the temperature held constant, additional chloroform is introduced into the system, and the vapor-liquid equilibrium is reestablished. Following this, the ...

chemistry
The vapour density of a gas is 22.4 and mass is. 22.4grams.what is the volume occupied the gas at N .T .P ?

Science, Chemistry
Hess's law ____. A) makes it possible to calculate ΔH for complicated chemical reactions B) states that when you reverse a chemical equation, the sign of ΔH does not change. C) determines the way a calorimeter works D) describes the vaporization of solids Highly ...

Chemistry
The pH of a .200M HBrO solution is 4.67. What is the acids Ka?

Chemistry
What would be the freezing and boiling points of a solution prepared by dissolving 1.00g of benzoic acid (C6H5CO2H) in 10.0g of benzene?

chemistry
What would be the freezing and boiling points of a solution of 5.00g of sodium chloride dissolved in 25.0g of water?

chemistry
20 mL of 0.125 M potassium iodide solution is mixed with 10 mL of 0.1 g L–1 sodium thiosulfate solution and 0.2 g of solid iodine indicator is added. To this solution is added 20 mL of 0.025 M peroxodisulfate solution. After 46 seconds a blue colour appears, indicating that ...

chemistry
hydrogen may not be advantagous as a fuel because

CHEMISTRY HELP !!!! CHECK !!!
Al3+ is reduced to Al(s) at an electrode. If a current of 2.75 ampere is passed for 36 hours, what mass of aluminum is deposited at the electrode? Assume 100% current efficiency. a. 9.2 x 10–3 g b. 3.3 x 101 g c. 9.9 x 101 g d. 1.0 x 102 g e. 3.0 x 102 g Answer 2.75 A for 36...

CHEMISTRY HELP ! Check Please!
Calculate the cell potential, at 25 C, based upon the overall reaction Zn2+(aq) + 2 Fe2+(aq) -> Zn(s) + 2 Fe3+(aq) if [Zn2+] = 1.50 x 10-4 M, [Fe3+] = 0.0200 M, and [Fe2+] = 0.0100 M. The standard reduction potentials are as follows: Zn2+(aq) + 2 e– --> Zn(s) E...

chemistry
If 80.6 pounds of alcohol are mixed with 42.7 pounds of water, what is the percent of water (by weight) in the mixture? Answer in units of %

chemistry
If 59.4 pounds of alcohol are mixed with 28.3 pounds of water, what is the percent alcohol (by weight) in the mixture? Answer in units of %

chemistry
what is the final temperature of amixture containning 25 grams of ice at -20 degree celciusadded to water at room temperature 22oC mass of water is 50g

Chemistry
The voltage generated by the zinc concentration cell described by, Zn(s)|Zn2 (aq, 0.100 M)||Zn2 (aq, ? M)|Zn(s) is 21.0 mV at 25 °C. Calculate the concentration of the Zn2 (aq) ion at the cathode.

Chemistry 104
A current of 3.40 A is passed through a Ni(NO3)2 solution for 1.80 hours. How much nickel is plated out of the solution?

Chemistry
So I am trying to understand in molecular terms the solubility of NaCl in water. So there are intramolecular forces that are mostly ionic between the ions, creating this partial positive, partial negative substance. And the intermolecular forces are also ionic. Ionic forces ...

Chemistry 104
The voltage generated by the zinc concentration cell described by, Zn(s)|Zn2 (aq, 0.100 M)||Zn2 (aq, ? M)|Zn(s) is 11.0 mV at 25 °C. Calculate the concentration of the Zn2 (aq) ion at the cathode.

chemistry
What is the final temperature when 54g ice at 0oC is mixed with 200g water at 65oC

Chemistry 104
A current of 3.40 A is passed through a Ni(NO3)2 solution for 1.80 hours. How much nickel is plated out of the solution?

Chemistry
Calculate the cell potential for the following reaction as written at 25.00 °C, given that [Cr2 ] = 0.859 M and [Ni2 ] = 0.0190 M. Standard reduction potentials can be found here.

Chemistry
Calculate the cell potential for the following reaction as written at 25.00 °C, given that [Cr2 ] = 0.859 M and [Ni2 ] = 0.0190 M. Standard reduction potentials can be found here.

Chemistry
How many grams of nitrogen are required to react with 2.79g of hydrogen to produce ammonia? A) 25.8 g B) 13.0 g C) 78.2 g D) 38.7 g E) 77.4 g I get the answer as 38.7 but it is meant to be B I did 2.79g x 3molH2/2.016g/mol x 1molN2/3molH2 x 28.02g/mol/1moleN2

Chemistry
What would the potential of a standard hydrogen (S.H.E.) electrode be if it was under the following conditions? [H+] = 0.38 P(H2) = 3.8 T = 298 K

Chemistry
Calculate the cell potential for the following reaction as written at 25.00 °C, given that [Cr2 ] = 0.859 M and [Ni2 ] = 0.0190 M. Standard reduction potentials can be found here. Cr+Ni(2+) ->Cr(2+) + Ni

Chemistry
Calculate the standard free-energy change for the following reaction at 25 °C. Standard reduction potentials can be found here. 2Au(3+) + 3Cr-->2Au+3Cr(2+)

Chemistry 104
A current of 3.40 A is passed through a Ni(NO3)2 solution for 1.80 hours. How much nickel is plated out of the solution?

College Chemistry
1 L of N_2_ gas, having a pressure of 2.5 atm, is added 1 L of Ar gas, having a pressure of 3.7 atm, in a sealed, rigid flask. What is the final pressure in the flask?

Steps in Chemistry
You notice that a lawn looks unhealthy and that, perhaps, the grass is dying. Undertake a scientific project to save the lawn. What is your initial hypothesis? Describe an experiment you can design to test it - include more than 1 step and variables. Hypothesis: “Adding ...

Chemistry
Write the formulas for silicon dioxide. SiO2 so how am i suppose to write formula(s) for it? like how ?

Chemistry
Complete and balance the following equation. Then write it as a net ionic equation. K3PO4(aq) + MgCl2(aq) Umm...help

Chemistry
I need help with Chemistry homework.. I don't know how to write formulas..Please help me! Write the formulas for silicon dioxide.

Chemistry
A solution of 22.0g of nonionic ascorbic acid in 100.0g of water freezes at – 2.33°C. What is the formula weight of the acid?

Chemistry
How much heat in kilojoules must be removed from a glass of water that contains 100g of water to lower its temperature from 30 C to 15 C?

chemistry
Assume you poured 5.00 g of KOH in 250 mL of pure water. What is the molarity of the solution you made?

Chemistry - Science (Dr. Bob222)
Nitrogen gas has values of Cv and Cp of 20.8 and 29.1 J K-1 mol-1, respectively. When a certain amount of nitrogen is heated at constant pressure, what fraction of the heat Q is used to increase the internal energy of the gas, and how is the remaining energy used? A) 3/2 of Q ...

Chemistry - Science (Dr. Bob222)
Hydrazine is used as a rocket fuel because its reaction with oxygen is extremely exothermic: N2H4(liquid) + O2(g)  N2(g) + 2H2O(liquid) ΔH(reaction) = -615 kJ mol-1 What is the enthalpy of this reaction if water were produced in the gaseous rather than the liquid ...

(12)Chemistry - Science (Dr. Bob222)
Calculate delta E for a process in which 88.0 g of nitrous oxide gas (N2O) is cooled from 165 ˚C to 65 ˚C at a constant pressure of 5.00 atm. The molecular weight of nitrous oxide is 44.02 g/mol, and its heat capacity at constant pressure, Cp, is 38.70 J/molK. A) - ...

(23.Chemistry - Science (Dr. Bob222)
An electrochemical battery made from Sn and Cu electrodes under standard conditions shows an initial voltage of V= 1.1 V. If the concentration of both Cu2+ and Sn2+ solutions is increased to 2 M from 1 M, the observed voltage will: (Hint: use the Nernst equation) A. increase ...

(19) Chemistry - Science (Dr. Bob222)
Use the following information to answer this question: Cu+(aq) + e- → Cu(s) E° = 0.521V Cu2+ (aq) + e- → Cu+ (aq) E° = 0.153 V. Given these half cell reactions, an aqueous solution of Cu+ ion in the absence of O2(g) : A. will be thermodynamically stable B. will ...

Chemistry
Calculate molarity of HNO3 please help? Calculate molarity of HNO3 prepared by dissolving 22.3 grams of HNO3 in water to make 875 ml of solution... Please help I'm stuck

chemistry
a 2.00 L ballon at 25 degrees celcius and 745mmHg floats on an altitude where the temperature is 10 degrees celcius and the air pressure is 700mmHg. what is the new volume othe balloon

Chemistry
Why is the first ionisation energy of chlorine greater than the first ionisation energy of Lithium ?

Chemistry
Please Help! Describe how water could be classified as either an acid or a base. Give an example of each (acid and base). What word describes substances that can be classified as acids or bases?

Chemistry
You can purchase hydrochloric acid in a concentrated form that is 37.0 hcl by mass and has a density of 1.20g/mL. Describe how exactly you would prepare 2.85 L of 0.500 M HCL from the concentrated solution.

chemistry
A cylinder contains 40 g of HE, 56 g of N2, and 40 g of Ar. How many moles of each gas are in the mixture?

chemistry
.256g unknown acid is titrated with .12M NaOH. It requires 34.8ml of base to reach the equivalence point. What is the molar mass of the acid?

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