In terms of energy, how would you classify the following chemical reaction?2Cu + O2 -> 2CuO + 315 kJ
a.endothermic
b.exothermic
c. both endothermic and exothermic
d. neither endothermic nor exothermic
2. The total amount of energy before and after a chemical reaction is the same. Thus, energy is
a. created
b. destroyed
c. conserved
d. the same as mass
Answers
1. Answer;
- Exothermic reaction
Explanation;
-Exothermic reactions are types of chemical reactions in which heat energy is released to the surroundings. Since enthalpy change is the difference between the energy of products an that of reactants. It means that in an exothermic reaction the energy of products is less than that of products. In this case an energy of 315kJ is released to the surroundings.
2. Answer;
Conserved
-The total amount of energy before and after a chemical reaction is the same. Thus, energy is conserved.
Explanation;
-According to the law of conservation of energy, energy is neither created nor destroyed. Energy may change form during a chemical reaction. For example, energy may change form from chemical energy to heat energy when gas burns in a furnace. However, the exact amount of energy remains after the reaction as before, which is true for all chemical reactions.
Answer:
Whole test
D
D
B
C
B
C
Explanation:
Related Questions
How would the equilibrium change if NO2 were added to SO2(g) + NO2(g) NO(g) + SO3(g) + heat?A. The equilibrium constant would increase. B. The amount of NO and SO3 would decrease. C. The amount of NO and SO3 would increase. D. The amount of NO2 and SO2 would increase.
HELP!!!!!! Multiple choiceDuring transmutation...A. the number of neutrons always decreases.B. the number of neutrons always increases.C. the number of protons always increases.D. the number of protons always decreases.
Knowing the chemical properties of a substance will tell you how the substancea. looks.c. can be broken down into atoms.b. smells.d. reacts with other substances.
An atomic nucleus must contain at least one neutron or else the force of attraction of the electron(s) will collapse the atom. True/false
Bombarding sodium-23 with a
proton produces nuclide X and a neutron. What is nuclide X?
Answers:
magnesium-24
magnesium-23
neon-23
s
odium-24
none of the above
The isotope P
has a half-life of 14.3 days. If a sample originally contained 1.00 g of P,
how much was left after 43 days?
Answers:
0.250 g
0.125 g
0.750 g
0.500 g
Identify X in the reaction
below.
U
+ C
→ Cf
+ X
Answers:
1
alpha particle
3
protons
6
neutrons
6
electrons
A .20 gram sample of C-14 was allowed to decay for 3 half-lives. What mass
of the sample will remain? Carbon-14 has a half life of 5730
years.
Answers:
0.025
0.05
0.1
0
.01
0.05
The isotope Cu
has a half-life of 30 s. If a sample originally contained 48 mg of Cu,
how much time passed before the amount fell to 3 mg?
Answers:
120 s
240s
30 s
60 s(when I did my calculation for the question above, I got 60 seconds)
What radionuclide decays to Fe-56
by beta emission?
Answers:
Fe
Co
Mn
Co
MnHow do I know wat it becomes. I put 57 Co 27 and it's wrong.
The Cf
to Cf
conversion is accompanied by __________.
Answers:
an alpha
emission
a
neutron capture
an electron
capture
an electron releaseI would greatly appreciate your help...ASAP. Thank you.
Answers
answer: neon
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The isotope P has a half-life of 14.3 days. If a sample originally contained 1.00 g of P,
how much was left after 43 days?
0 days >>> 1.00g
14,3 days >>> 1.00g :2 = 0,5g
(14.3+14.3) days >>> 0.5g : 2 = 0.25g
(14.3+14.3+14.3) days >>> 0.25g : 2 = 0.125g
answer: 0.125g
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Identify X in the reaction
below.
U + C → Cf + X
answer: 6 electrons (so it's beta⁻)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
A .20 gram sample of C-14 was allowed to decay for 3 half-lives. What mass
of the sample will remain? Carbon-14 has a half life of 5730
years.
at the beginning >>> 0.20g
1 half-live >>> 0.20g : 2 = 0.10g
2 half-live >>> 0.10g : 2 = 0.05g
3 half-live >>> 0.05g : 2 = 0.025g
answer: 0.025g
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The isotope Cu has a half-life of 30 s. If a sample originally contained 48 mg of Cu,
how much time passed before the amount fell to 3 mg?
0 s (at the beginning) >>> 48mg
30s >>>>>>>>>>>>>>> 48mg : 2 = 24mg
(30+30)s >>>>>>>>>>> 24mg : 2 = 12mg
(30+30+30)s >>>>>>>> 12mg : 2 = 6mg
(30+30+30+30)s >>>>> 6mg : 2 = 3mg
answer: 30+30+30+30 = 120s
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
What radionuclide decays to Fe-56 by beta emission?
answer: ⁵⁶₂₇Co
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The Cf to Cf conversion is accompanied by __________.
Cf to Cf ???? maybe...mistake?
1- 5 grams O2 / 1 gram C3H8
2- 5 moles O2 / 1 mole C3H8
3- 10 grams O2 / 11 grams C3H8
4- 10 moles O2 / 11 moles C3H8
Answers
Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, 5 moles oxygen / 1 mole propane. The correct option is option C among all the given options.
What is mole?
The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity or amount of substance. We know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number.
The balanced equation for the given chemical reaction can be given as
CH
+ 5O
3CO
+ 4H
O
Stoichiometry represents the number of number of moles of reactant and products. The mole ratio between oxygen and propane is 5:1. the correct option isoption 2.
Therefore, 5 moles oxygen / 1 mole propane. The correct option is option C among all the given options.
To know more about mole, here:
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Answers
Answers
Answer:
i) Highest osmotic pressure: CaCl2
ii) lower vapor pressure : CaCl2
iii) highest boiling point : CaCl2
Explanation:
The colligative properties depend upon the number of solute particles in a solution.
The following four are the colligative properties:
a) osmotic pressure : more the concentration of the solute, more the osmotic pressure
b) vapor pressure: more the concentration of the solute, lesser the vapor pressure.
c) elevation in boiling point: more the concentration of the solute, more the boiling point.
d) depression in freezing point: more the concentration of the solute, lesser the freezing point.
the number of particle produced by urea = 1
the number of particle produced by AgNO3 = 2
the number of particle produced by CaCl2 = 3
As concentrations are same, CaCl2 will have more number of solute particles and urea will have least
i) Highest osmotic pressure: CaCl2
ii) lower vapor pressure : CaCl2
iii) highest boiling point : CaCl2
Final answer:
The solution with the highest number of particles in solution (CaCl2 in this case), experiences the highest osmotic pressure, lowest vapor pressure and highest boiling point due to the principles of colligative properties.
Explanation:
The question pertains to the colligative properties of solutions, which would be governed by the number of particles in the solution. The solutions are 0.04 m urea [(NH2)2C=O)], 0.04 m AgNO3, and 0.04 m CaCl2. For (i) Highest osmotic pressure, the solution with the highest ion count would yield the highest osmotic pressure. CaCl2 dissociates into three ions (Ca²+, and 2 Cl¯), therefore, it would exhibit the highest osmotic pressure. For (ii) Lowest vapor pressure, this would coincide with the solution with the highest osmotic pressure, again making it CaCl2, due to the greatest decrease in vapor pressure. For (iii) the highest boiling point, this too would be CaCl2 for the reasons stated above. The presence of more particles in a solution interferes more with the evaporation process, requiring more energy (higher temperature) to achieve boiling.
Learn more about Colligative Properties here:
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Answers
Here are some:-
Krypton
Argon
Neon