Answer:
The amount of kilograms of ice at -20.0°C that must be dropped into the water to make the final temperature of the system 40.0°C = 0.0674 kg
Explanation:
Heat gained by ice in taking the total temperature to 40°C = Heat lost by the water
Total Heat gained by ice = Heat used by ice to move from -20°C to 0°C + Heat used to melt at 0°C + Heat used to reach 40°C from 0°C
To do this, we require the specific heat capacity of ice, latent heat of ice and the specific heat capacity of water. All will be obtained from literature.
Specific heat capacity of ice = Cᵢ = 2108 J/kg.°C
Latent heat of ice = L = 334000 J/kg
Specific heat capacity of water = C = 4186 J/kg.°C
Heat gained by ice in taking the total temperature to 40°C = mCᵢ ΔT + mL + mC ΔT = m(2108)(0 - (-20)) + m(334000) + m(4186)(40 - 0) = 42160m + 334000m + 167440m = 543600 m
Heat lost by water = mC ΔT = 0.25 (4186)(75 - 40) = 36627.5 J
543600 m = 36627.5
m = 0.0674 kg = 67.4 g of ice.
The answer is 523.60 rounded. To get this use the formula: V=4/3 • π • r^3 = 4/3·π·(53) ≈ 523.59878. Which is four over three, multiplied by “pie” multiplied by the radius cubed. (Which is 5 • 5 • 5). To get the radius, you split the diameter in half. For you equation, “1/2 of ten is five” so the radius is five. Hope this helps!
Answer:
- 0.86 C
Explanation:
Let the temperature of cold reservoir is T2.
T1 = 22.4 C = 295.4 K, B = 11.7
By the formula of coefficient of performance of heat pump
B = T2 / (T1 - T2)
11.7 = T2 / (295.4 - T2)
11.7 × 295.4 - 11.7 T2 = T2
T2 = 272.14 K
T2 = - 0.86 C
Explanation:
It is given that,
Initial state of electron,
Final state of electron,
The wavelength of the excited electron is given by :
Where
R is Rydberg's constant
or
Let f is the frequency of the observed photon. It is given by :
Hence, this is the required solution.
At pH = 2 the ratio of the concentration of the hydrogen to the hydroxide ion is 10¹⁰. The hydrogen ion concentration at pH, 2 is 10⁻² and the hydroxide ion is 10⁻¹².
<h3>What is pH?</h3>
The parameter of measuring the concentration of the hydroxide and the hydrogen ion in the solution in order to determine the basic and the acidic nature is known as pH.
The concentration of H⁺ ions is calculated as:
pH = -log [H⁺]
2 = -log [H⁺]
[H⁺] = 10⁻²
The concentration of OH⁻ ions is calculated as:
pH + pOH = 14
pOH = 14 - 2
pOH = 12
Solving further:
pOH = -log [OH⁻]
12 =-log [OH⁻]
[OH⁻] = 10⁻¹²
At a pH = 2, the ratio of hydrogen ions to hydroxide ions:
10⁻² ÷ 10⁻¹² = 10¹⁰
Therefore, at pH = 2 the ratio is 10¹⁰.
Learn more about pH here:
brainly.com/question/20438548
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