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dsp73
4 years ago
13

calculate the change in enthalpy, if the reactants have an enthalpy of 315 kj and the products have an enthalpy of 375 kj

Chemistry
1 answer:
sineoko [7]4 years ago
5 0

25% is the answer, i believe.

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Use the periodic table to identify the element indicated by each electron configuration by typing in the chemical symbol for the
Schach [20]

Answer:

1s22s22p6: Ne 1s22s22p63s23p3: P 1s22s22p63s23p64s1: K 1s22s22p63s23p64s23d8: Ni 1s22s22p63s23p64s23d104p65s24d3: Nb

6 0
2 years ago
Identify each energy exchange as primarily heat or work and determine whether the sign of ΔE is positive or negative for the sys
Semmy [17]

Answer:

a. Work, ΔE is negative;

b. Work, ΔE is negative;

c. Work, ΔE is positive.

Explanation:

In the three cases, there is energy exchange in primarily work. The heat is the energy flow because of the difference in temperature. Of course, some heat may be lost in the cases by dissipation.

In the letter <em>a</em> the system is at an initial velocity different from 0, and then it stops. The energy that is represented here is the kinetic energy, which is the energy of the movement. Note that the system goes from a higher velocity to 0, so it is losing kinetic energy, or work, so ΔE = Efinal - Einitial < 0.

In letter <em>b</em>, the system is falling from a certain high to the floor, so its gravitational potential energy is change. That potential energy represents the energy that gravity does when an object shifts vertically. Because it goes from a high to 0, the energy is been lost, so ΔE = Efinal - Einitial < 0.

In letter <em>c</em>, the system is going higher and with higher velocity, so there is a greatness in the gravitational potential energy and the kinetic energy, both works, so ΔE = Efinal - Einitial > 0.

8 0
3 years ago
Which of the following occurs due to static electricity? Question 9 options: lightening sunlight star light moon phases
horrorfan [7]
<h3><u>Answer;</u></h3>

Lightening

<h3><u>Explanation;</u></h3>
  • Static electricity occurs when there is an imbalance of positively and negatively charged atoms. Electrons then jump from atom to atom, releasing energy.
  • Lightening occurs as a result of a build up of electric charge in a cloud. It occurs when negative charges jump from a cloud to the ground.
  • The result of electrons moving from one place to another and cause a buildup of separated positive and negative charges creates a static charge.
7 0
3 years ago
How many grams of hydrogen is produced from 12.5 G of MG reacting with hydrochloric acid in this balanced equation?
k0ka [10]

Answer:

1.03 grams of hydrogen is produced from 12.5 g of Mg reacting with hydrochloric acid.

Explanation:

The balanced reaction is:

Mg+ 2 HCl → MgCl₂ + H₂

By stoichiometry of the reaction, the following amounts of moles of each compound participate in the reaction:

  • Mg: 1 mole
  • HCl: 2 moles
  • MgCl₂: 1 mole
  • H₂: 1 mole

Being the molar mass of each compound:

  • Mg: 24.31 g/mole
  • HCl: 36.45 g/mole
  • MgCl₂: 95.21 g/mole
  • H₂: 2 g/mole

By reaction stoichiometry, the following mass amounts of each compound participate in the reaction:

  • Mg: 1 mole* 24.31 g/mole= 24.31 g
  • HCl: 2 moles* 36.45 g/mole= 72.9 g
  • MgCl₂: 1 mole* 95.21 g/mole= 95.21 g
  • H₂: 1 mole* 2 g/mole= 2 g

Then you can apply the following rule of three: if by stoichiometry 24.31 grams of Mg produces 2 grams of H₂, 12.5 grams of Mg produces how much mass of H₂?

mass of H_{2} =\frac{12.5 grams of Mg* 2 grams of H_{2}}{24.31 grams of Mg}

mass of H₂= 1.03 grams

<u><em>1.03 grams of hydrogen is produced from 12.5 g of Mg reacting with hydrochloric acid.</em></u>

5 0
3 years ago
Which two climates have very low levels of precipitation
miv72 [106K]

Answer:

B highlands and polar, very little percipitation is found in polar regions, and high lands contributes to that

Explanation:

7 0
3 years ago
Read 2 more answers
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