Answer:
-15-12-14=-13
Explanation:
we simplify by opening the bracket
What is the Hsol for KF →K+ + F-? The lattice energy is –784 kJ/mol, the enthalpy of hydration for Ki is –336
kJ/mol, and the enthalpy of hydration for F-is-431 kJ/mol. Use AHsol= - Hiat + Hydr
0-879 kJ/mol
0 -17 kJ/mol
O 17 kJ/mol
O 1,551 kJ/mol
Answer:
17 kJ/mol
Explanation:
got it on edge
Which sentence in paragraph 1 explains what Americans are doing to help the environment?
O a. Today, 60 percent of us believe that climate change is a serious threat.
O b.In 1980, coal, oil and gas made up 89 percent of the energy we used.
0
c. 90 percent of us have recycled in the last year.
O d. Sometimes you can even find low belief in climate change.
HELP ITS DUE IN AN HOUR!!
What is a lattice position?
Explain
Explanation:
Crystallography. an arrangement in space of isolated points (lattice points ) in a regular pattern, showing the positions of atoms, molecules, or ions in the structure of a crystal.
If an atom experiences sufficient thermal activation, it can move to a neighboring lattice position.4 If the vibration frequency of the atom is v and the atom has Z nearest neighbors, the total number of jump attempts is vZ. However, only a small fraction of the attempts will be successful, with a probability depending on the ratio between the necessary activation energy for a single jump QD and the thermal activation kBT. The effective jump frequency ΓD is then
(5.6)
With each successful jump, the atom travels one atomic distance λ and the total traveling distance in unit time is thus ΓDλ. Substituting the jump frequency ΓD into the expression for the root mean square displacement of a random walker [equation (5.5)] and using the spatial coordinate r leads to
What is metal ? Where does it coke from ?
Answer:
Most pure metals, like aluminium, silver and copper, come from the Earth's crust. They are found in ores – solid materials called minerals, usually occurring in rock, from which the pure metal has to be extracted. The properties of pure metals can be improved by mixing them with other metals to make alloys.a metal is an element that readily forms positive ions (cations) and has metallic bonds
coke is a strong stimulant made from coca leaves
Which of the following statements is true about the molecule shown below?
Answer:
B. The bonds are polar and the molecule is nonpolar.
Explanation:
Each bond in the molecule is polar, as indicated by the partial charges on the atoms of the molecule. However, the four atoms are arranged symmetrically around the central atom. In this case, the effects of the partial charges on opposite sides cancel out. As a result, the molecule as a whole is nonpolar. If exposed to an electric field, the molecule will not orient itself in any particular direction.
PLEASE HELP ME ASAP!!!!!! YOU GET 10 POINTS!!!!!!
For reaction below, describe how its equilibrium could be shifted in the indicated direction.
1. H2(g)+C12(g)<---------->2HC1(g)+thermal energy: shift to the left
2.C(s) +O2(g)<---------->CO2+thermal energy: shift to the right
Answer:
Here is the ANSWER KEY, it may also has other of the questions you don't know :)
Explanation:
https://sciencewithhorne.weebly.com/uploads/5/7/3/5/57358947/unit_11_hw_key.pdf
Helpp plzz..10pointss
Calculemos la formula empirica y molecular de carbonato de hierro Fe2(co3)3.Fe.38.3%C.12.3%.0.4 92% masa 292g
Respuesta:
292 g / mol;
Por favor, consulte la explicación.
Explicación:
El número de átomos de cada elemento en el compuesto: Fe2 (co3) 3.
Fe = 2; C = 3; 0 = 3 * 3 = 9
Fe2 = 112 g / mol
C = 12 g / mol
O = 16 g /
Masa molecular = ((112 + (12 * 3) + (16 * 9)
= (112 + 36 + 144)
= 292 g / mol.
Total = 2 + 3 + 9 = 14
Fe2 = 112/292 * 100% = 38,356%
C = 36/292 * 100% = 12,328 * '
O = (16 * 9) / 292 * 100% = 49,32%
What phase is not part of mitosis and is where the cells spends most of its time
Answer:
interphase
Explanation:
they spend most time in interphase
Which of these boxes will not accelerate?
Answer:
B as all the forces cancel out
Explanation:
20-20=0
25-25=0
How many atoms in 12 moles of Mg?
CaC2(s) + 2H2O(l) --> Ca(OH)2(aq) + C2H2(g) In the reaction above, 0.5487 grams of calcium carbide are completely consumed to produce acetylene gas, C2H2. What volume (in mL) will this gas occupy if it is collected at 43 degrees Celsius and 0.926 atm pressure
Answer:
239.7mL
Explanation:
Using the general gas equation;
PV = nRT
Where;
P = pressure (atm)
V = volume (L)
n = number of moles (mol)
R = gas constant (0.0821 Latm/molK)
T = temperature (K)
The balanced chemical equation in this question is as follows:
CaC2(s) + 2H2O(l) --> Ca(OH)2(aq) + C2H2(g)
From the equation, 1 mole of CaC2 produces 1 mole of ethylene gas, C2H2.
Using mole = mass/molar mass
Molar mass of CaC2 = 40 + 12(2)
= 40 + 24
= 64g/mol
mole = 0.5487/64
mole = 0.00857mol of CaC2
Hence, 0.00857mol of CaC2 produced 0.00857mol of C2H2
Based on the information provided, n = 0.00857mol, T = 43°C = 43 + 273 = 316K, p = 0.926 atm
PV = nRT
V = nRT/P
V = 0.00857 × 0.0821 × 316/0.926
V = 0.222/0.926
V = 0.2397L
In mL, volume = 0.2397 × 1000
= 239.7mL
A 55 kg person on Earth has the __________mass on the moon.
Answer:
89.1 N
Explanation:
W = m gm = 55.0 x 1.62 = 89.1 N
Which statement correctly describes the relationship between air temperature and air pressure?
-Warm air rises, creating an area of low pressure.
-Cool air sinks, creating an area of low pressure.
-Warm air sinks, creating an area of low pressure.
-Cool air rises, creating an area of low pressure.
Answer:
-Warm air sinks, creating an area of low pressure.
Explanation:
Heat will weigh more, than cool air!
Help for extra points & brainlest !
Answer: i think is true
Explanation:
True. Cells have jobs in your body as they have functions to do.
Which of the nine substances are made of four elements?
Answer:
Oxygen mucury carbon dioxide and platinum
Explanation:
Question 25 points)
Obsidian is a glassy black igneous rock. A sample of obsidian is shown.
Which type of rock forms in a similar manner as obsidian but at a slower
rate?
Oa
Oь
Ос .
Od
schist, which forms under extreme heat and pressure
conglomerate, which forms when different-sized sediments cement together
gypsum, which forms when water evaporates and leaves behind minerals
granite, which forms as magma cools deep underground
Answer:
Granite
Explanation:
Answer:
Granite
Explanation:
Igneous forms when rock is cooled and hardens by Magma.
And the option granite, which forms as magma cools deep underground
Hope it helps have a Good Day
an element has atomic number of 17 state the elements group and period number
Answer:
The element is in group 7, the halogens. The element is in the third period or row of the table.
Explanation:
Chlorine is element number 17.
I need help please i need to turn this in today
Answer:
Natural phenomena such as melting glaciers is due to the rise in temperature. This will result to extinction of flora and fauna. Moreover it can cause extreme flooding due to rise in water level in other water bodies such as rivers, lakes
19. A piece of unknown metal with a mass of 62.0g and an initial temperature of 95.3°C is dropped into
100.0g of water with an initial temperature of 27.0°C. The final temperature of the system is 34.0°C.
Answer:
a
Explanation:
How much energy is released when 67.04g of phosphorous is reacted with 10.20g of chlorine? ___ P + ___ Cl2 ___ PCl3 ΔH = -574 kJ
Answer:
26.78 kJ
Explanation:
To solve the problem, we have to first write the stoichiometric coefficients in the chemical equation:
2P + 3Cl₂ → 2PCl₃
With these coefficients, we have the same number of atoms of each chemical element on both sides: 2 atoms of P, 6 atoms of Cl.
According to the equation, 2 moles of phosphorous (P) react with 3 moles of chlorine (Cl₂), and 574 kJ of energy are released. We have to figure out which is the limiting reactant. For this, we convert the mass into moles by using the molar mass(MM):
MM(P) = 30.9 g/mol
67.04 g P/(30.9 g/mol) = 2.17 mol P
MM(Cl₂) = 35.4 g/mol x 2 = 70.8 g/mol
10.20 g Cl₂/(70.8 g/mol) = 0.14 mol Cl₂
Now, we multiply the actual moles of P (the amount we have for the reaction) by the stoichiometric ratio given by the chemical equation (3 mol Cl₂/2 mol P):
2.17 mol P x (3 mol Cl₂/2 mol P) = 3.25 mol Cl₂
To completely react 67.04 g P, we need 3.25 mol of Cl₂, and we have only 0.14 moles of Cl₂, so the limiting reactant is Cl₂.
Now, we use the limiting reactant to calculate the energy released from the reaction. The energy released per mole of Cl₂ is:
ΔH/(3 mol Cl₂) = -574 kJ/3 mol Cl₂= 191.3 kJ/mol Cl₂
Finally, we multiply the energy released per mole of Cl₂ by the number of moles of Cl₂ we have:
0.14 mol Cl₂ x 191.3 kJ/mol Cl₂ = 26.78 kJ
Use the following information to answer the following question.
Cu + 2 AgNO3 --> Cu(NO3)2 + 2 Ag
12.7 g of copper metal reacts with silver nitrate to actually produce 38.1 g of silver in the lab.
Percent Yield = Actual Yield/Theoretical Yield x 100%
What is the percent yield of silver (Ag) in this reaction?
Answer:
For these problems, we need to compare the theoretical yield that we'd get from performing stoichiometry to the actual yield stated in the problem. % yield is the actual yield/theoretical yield x 100%
Cu + 2 AgNO₠→ Cu(NOâ‚)â‚‚ + 2 Ag ==> each mole of copper yields two moles of silver
12.7-g Cu x ( 1 mol Cu /63.5-g Cu) x ( 2 mol Ag / 1 mol Cu) x (108-g Ag / 1 mol Ag) = 43.2-g Ag. This is the theoretical yield. Now, since we got 38.1-g Ag our % yield is:
38.1-g/43.2-g x 100% = 88.2%
Explanation:
How many atoms are in 3.6 moles of titanium?
Answer:
69420
Explanation:
Answer:
We need to calculate number atoms, which can be determined as follows: We know that 1 mol contains 6.02214076×1023 number of atoms. i.e. is Avogadro's constant. Therefore the answer to the above question is that the number of atoms in 3.5 mol of Arsenic is 2.11×104 number of atoms.
Explanation:
PLEASE HELP ASAP!!!!!!????
Answer:
The third one!
how is salt obtained or manufactrured
Answer:
There are three methods used to produce salt: solar, evaporation and rock mining.
Explanation:
Exothermic or Endothermic ~N2(g) + 2 O2(g) → 2 NO2(g) ΔH= +67.6 kJ
Explain why?
Answer:
endothermic
Explanation:
Because the value of the heat of reaction is positive .
1.
John ground some coffee beans into little pieces. He put them into a coffee filter and poured
800 cm3 of boiling water over them to make a jug of coffee.
coffee filter
Coffee
Beans
ON
jug of coffee
(a) Complete the sentences below. For each sentence, choose one of the following
words.
insoluble
soluble
solution
solvent
(0)
The liquid in the jug is brown because parts of the coffee beans
are
in water.
1 mark
How many formula units are in 9.8 grams of calcium hydroxide?
Answer:
There are 9.8 ×1021. formula units in 10,005.8gCaO
At 25◦C a 4 L sample of H2 exerts a pressure of 5 atm. What pressure would the same sample exert in a 2 L container at 25◦C?
Answer:
10 atm.
Explanation:
Using the combined gas law equation as follows;
P1V1/T1 = P2V2/T2
Where;
P1 = initial pressure (atm)
P2 = final pressure (atm)
V1 = initial volume (L)
V2 = final volume (L)
T1 = initial temperature (K)
T2 = final temperature (K)
According to the information provided in this question,
P1 = 5 atm
P2 = ?
V1 = 4L
V2 = 2L
T1 = 25°C = 25 + 273 = 298K
T2 = 25°C = 298K
Using P1V1/T1 = P2V2/T2
5 × 4/298 = P2 × 2/298
20/298 = 2P2/298
Cross multiply
298 × 20 = 298 × 2P2
5960 = 596P2
P2 = 5960 ÷ 596
P2 = 10 atm.
.
Characteristics of a Group of Elements
Do not conduct electricity
• Mostly gas, but brittle when solid
Has 7 valence electrons
.
Which of these elements is in this groun?
Answer:
Gas
Explanation:
I dunno but a lucky guess i guess
