When ice melts, the physicals state changes from solid to liquid. The energy or the heat required (q) required to change a unit mass (m) of a substance from solid to liquid is known as the enthalpy or heat of fusion (ΔHf). The variables; q, m and ΔHf are related as:
q = m * ΔHf
the mass of ice m = 65 g
the heat of fusion of water at 0C = ΔHf = 334 J/g
Therefore: q = 65 g * 334 J/g = 21710 J
Now:
4.184 J = 1 cal
which implies that: 21710 J = 1 cal * 21710 J/4.184 J = 5188.8 cal
Hence the heat required is 5188.8 cal or 5.2 Kcal (approx)
Answer:
En toda la población del mundo hay <u>0.0797 moles de células</u>
Explanation:
1.0 mol of cells = 6.022 * 10∧23 cells
X mol of cells = 6.0 * 10∧12 cells
- X is cleared to find out how many moles of cells are in a human body:
- X = 6.0 * 10∧12 cells / 6.022 * 10∧23 cells
- X = 9,963 * 10∧-12 moles of cells per person
In the world there are 8 * 10∧9 people, how many moles in total will there be?
8 * 10∧9 people * 9,963 * 10∧-12 moles of cells per person =
<u>0.0797 moles of molecules in the entire population of the earth.</u>
There’s no question for me to answer ?
The new volume at standard pressure of 1 atm is 21294 liters.
Explanation:
Data given:
Initial volume of the gas V1 = 338 liters
initial pressure on the gas P1 = 63 atm
standard pressure as P2 = 1 atm
Final volume at standard pressure V2 =?
The data given shows that Boyle's law equation is to used:
P1V1 = P2V2
rearranging the equation to calculate V2,
V2 = 
Putting the values in the equation:
V2 = 
= 21294 L
as the pressure on the gas is reduced to 1 atm the volume of the gas increased incredibly to 21294 litres.
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