How many calories are absorbed by a sample water with a mass of 500 grams as it changes from 50 degrees C to 65 degrees C?
Answers
H = mCpT
H = (500 grams water)( 4.18 J/ g - degrees C) (65 - 50)
H =31,350 J
since 1 cal = 4184 joules
31,350 Joules (1 calorie/ 4184 joules) = 7.49 calories
Related Questions
If you begin with 1250 grams of N2 and 225 grams of H2 in the reaction that forms ammonia gas (NH3), how much ammonia will be formed? What is the limiting reagent? How much of the reagent is left when the maximum amount of ammonia is formed?(AP Chemistry summer homework packet)Please help! Thanks. :)
_____ magma is a mix between basaltic and rhyolitic magma. The eruption that would most likely result from this magma is a _____ eruption.
Consider three gases: Ar, SF6, and Cl2. If 50.0 grams of these gases are placed in each of three identical containers, which container will have the highest pressure? The volume and temperature of all three containers are the same.
Democritus was a Greek philosopher living from c. 460 B.C. to c. 370 B.C. He wrote several suppositions on the properties of matter.Which of the following statements most closely describes Democritus's ideas about matter? A. All matter is composed of tiny particles that can vary in shape, size, and weight. B. Solid matter is composed of square-shaped particles and liquid matter is composed of flat particles. C. Solid matter is composed of atoms and liquid matter is composed of elements.
Answers
Answer:
Se + 2e- => Se-2
Explanation:
Ions are electrically charged particles, formed due to the gain or loss of electrons by an atom.
There are two types of ions cations and anions. An element that loses their electrons and forms positive ions are cations while metals and element that gains one or more electrons and forms negative ions are anions.
Selenium is an atom with atomic number 34 and represented as Se. The electronic configuration of Se is 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p4. Selenium will gain 2 more electrons to complete it p orbital and form an ion Se-2.
The equation is as below:
Se + 2e- => Se-2
0 100
15 50
30 25
45 12.5
Based on the observations, which of these is most likely David's inference?
A.The half life period of radioactive sodium is 15 hours.
B.The half life period of radioactive sodium is 50 hours.
C.The amount of sodium left in the container after 60 hours will be 10.5 grams.
D.The amount of sodium left in the container after 60 hours will be 1.5 grams.
Answers
Answer: A. The half life period of radioactive sodium is 15 hours.
Explanation:
Half life is the time taken by a reactant to reduce to its original concentration. It is designated by the symbol .
Given:
At 0 hours the amount of sodium in container is 100 grams
After 15 hours , the amount of sodium in container is 50 grams which is half of the original amount of 100 grams.
It will take 15 hours for half of a 100 g sample to decay to half of the amount i.e. 50 grams.
When balancing the nuclear reaction, explain the following:
How does the Law of Conservation of Matter dictate what the daughter nuclide is?
How do we calculate the atomic mass and atomic number for the daughter nuclide?
Where do we look up what the new daughter nuclide element is?
Answers
1) number of protons and neutrons on both side of nuclear reaction must be the same. There are 91 protons (atomic number) and 143 neutrons (mass number - atomic number, 234 - 91 = 143 or (4-2) + (230 - 89) = 143)) on both side of reaction.
2) alphadecay is radioactive decay in whichan atomic nucleus emitsan alpha particle (heliumnucleus) and transforms into an atom with an atomicnumber that is reduced by two and mass number that is reduced by four, so atomic mass of new element is 89 (91 - 2) and mass number is 230 (234 - 4 = 230).
3) look at atomic number, element with atomic number 89 is actinium.
Final answer:
The balanced nuclear reaction is 234/91 Pa -> 4/2 He + 230/89 Ac. You calculate the atomic mass and atomic number of the daughter nuclide by subtracting the atomic mass and atomic number of the alpha particle from the parent nuclide. Then, refer to the periodic table to identify the element with the corresponding atomic number.
Explanation:
The process described in the question is a typical alpha decay nuclear process. In this reaction, a Protactinium-234 nuclide emits an alpha particle (which is a Helium nucleus) to produce a new nuclide, the daughter nuclide.
According to the Law of Conservation of Matter, the sum of the mass and atomic numbers (protons + neutrons) of the reactants must equal the sum of the mass and atomic numbers of the products. This means we can calculate the atomic number and atomic mass of the daughter nuclide. The atomic mass would be the difference: 234 - 4 = 230. The atomic number would be the difference: 91 - 2 = 89.
After that, you can identify the new element by its atomic number, 89, from a periodic table, which shows it to be Actinium (89/230 Ac).
So, the balanced nuclear reaction is: 234/91 Pa -> 4/2 He + 230/89 Ac
Learn more about Balancing Nuclear Reactions here:
#SPJ3
-1,514 kcal
-33.3 kcal
-135.2 kcal
-none of the above
Answers
base from the reaction, the stoichiometric ratio is 1 mole CO produce 67.6 kcal so the anwer is - 67.6 kcal because is it exothermic
I got 67.6 kcal not -67.6
Answers
The intermolecular forces increase with increasing polarization of bonds. The strength of intermolecular forces (and therefore impact on boiling points) is ionic > hydrogen bonding > dipole dipole > dispersion. "Boiling point increases with molecular weight, and with surface area" says one article
B.) melting ice
C.) condensing steam
D.) dissolving ammonium nitrate in water
Answers
Answer:
C.) condensing steam
Explanation:
Exothermic reactions are chemical reaction which energy is released to the environment in the form of heat . The overall energy of the reactant is greater than the energy of the product. The higher in energy of the reactant causes a release of heat to the environment. In exothermic reactions, enthalpy change is usually negative and is accompanied by the loss of energy in the form of heat or light.
Condensation is the change of water vapor to liquid . The conversion is an exothermic reaction as energy is release to the environment in the form of heat. The water vapor molecules has higher energy than liquid. The changes of water vapor to liquid causes a loss in energy of the water vapor. As the water vapor loss more energy, heat is been release to the surrounding.
All other reaction are endothermic in which heat is absorb from the environment except for condensation of steam.
The event that is an example of an exothermic reaction is condensing steam. The answer is letter C. An exothermic reaction is one in which there is a release of heat during the reaction. Dissolving sugar in water, melting ice and dissolving ammonium nitrate in water are all examples of an endothermic reaction.