Answer:
Heat transfer = Q = 62341.6 J
Explanation:
Given data:
Heat transfer = ?
Mass of water = 50.0 g
Initial temperature = 30.0°C
Final temperature = 55.0°C
Specific heat capacity of water = 4.184 J/g.K
Solution:
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = 55.0°C - 30.0°C
ΔT = 25°C (25+273= 298 K)
Q = 50.0 g × 4.184 J/g.K ×298 K
Q = 62341.6 J
Answer:
fH = - 3,255.7 kJ/mol
Explanation:
Because the bomb calorimeter is adiabatic (q =0), there'is no heat inside or outside it, so the heat flow from the combustion plus the heat flow of the system (bomb, water, and the contents) must be 0.
Qsystem + Qcombustion = 0
Qsystem = heat capacity*ΔT
10000*(25.000 - 20.826) + Qc = 0
Qcombustion = - 41,740 J = - 41.74 kJ
So, the enthaply of formation of benzene (fH) at 298.15 K (25.000 ºC) is the heat of the combustion, divided by the number of moles of it. The molar mass od benzene is: 6x12 g/mol of C + 6x1 g/mol of H = 78 g/mol, and:
n = mass/molar mass = 1/ 78
n = 0.01282 mol
fH = -41.74/0.01282
fH = - 3,255.7 kJ/mol
The number of oxygen atoms is in 5.00 g of sample of sodium dichromate, Na₂Cr₂O₇ is 1.125 x 10²³ atoms.
<h3>What is sodium dichromate?</h3>
Sodium dichromate is an inorganic compound. It is sued in tanning and mental illness.
The molar mass of sodium = 23 gm
The molar mass of Cr = 51.99 gm
The molar mass of oxygen = 16 gm
Molar mass of Na₂Cr₂O₇ = 2(23) + 2(51.99) + 7(16) = 261.98 gm
Number of moles in 7 gm = mass / molar mass = 7 / 261.98 = 0.0267 moles
1 mole of Na₂Cr₂O₇ contains 7 moles of oxygen, therefore:
The number of moles of oxygen in 0.0267 moles = 0.0267 x 7 = 0.1869 moles
Thus, the number of atoms = 0.1869 x 6.02 x 10^23 = 1.125 x 10²³ atoms.
To learn more about sodium dichromate, refer to the link:
brainly.com/question/1444529
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Answer:
0.85 mol/L.
Explanation:
- Molarity is defined as the no. of moles of solute dissolved in a liter of the solution.
<em>M = (no. of moles of solute)/(Volume of the solution (L))</em>
no. of moles of calcium phosphate = 2.125 mol.
Volume of the solution = 2.5 L.
<em>∴ M of calcium phosphate</em> = (2.125 mol)/(2.5 L) = <em>0.85 mol/L.</em>
It’s the 3rd one obviously bro
