Answer:
Explanation:
moler mass of Cu is 63.546 g/mol. Since 63.546 g of copper has 6.022 x 10 power(23) atoms (Avogadro's number). = 9.5 x 10(power)21 atoms of copper.
Answer:
The total energy of the photons detected in one hour is 7.04*10⁻¹¹ J
Explanation:
The energy carried by electromagnetic radiation is displaced by waves. This energy is not continuous, but is transmitted grouped into small "quanta" of energy called photons. The energy (E) carried by electromagnetic radiation can be measured in Joules (J). Frequency (ν or f) is the number of times a wave oscillates in one second and is measured in cycles / second or hertz (Hz). The frequency is directly proportional to the energy carried by a radiation, according to the equation: E = h.f, (where h is the Planck constant = 6.63 · 10⁻³⁴ J / s).
Wavelength is the minimum distance between two successive points on the wave that are in the same state of vibration. it is expressed in units of length (m). In light and other electromagnetic waves that propagate at the speed of light (c), the frequency would be equal to the speed of light (≈ 3 × 10⁸ m / s) between the wavelength :
![f=\frac{speed of light}{wavelength}](https://tex.z-dn.net/?f=f%3D%5Cfrac%7Bspeed%20of%20light%7D%7Bwavelength%7D)
So:
![E=\frac{h*speed of light}{wavelength}](https://tex.z-dn.net/?f=E%3D%5Cfrac%7Bh%2Aspeed%20of%20light%7D%7Bwavelength%7D)
In this case, the wavelength is 3.35mm=3.35*10⁻³m and the energy per photon is:
![E=\frac{6.63*10^{-34}*3*10^{8}}{3.35*10^{-3} }](https://tex.z-dn.net/?f=E%3D%5Cfrac%7B6.63%2A10%5E%7B-34%7D%2A3%2A10%5E%7B8%7D%7D%7B3.35%2A10%5E%7B-3%7D%20%7D)
E=5.93*10⁻²³ ![\frac{J}{proton}](https://tex.z-dn.net/?f=%5Cfrac%7BJ%7D%7Bproton%7D)
The detector is capturing 3.3*10⁸ photons per second. So, in 1 hour:
![E=5.93*10^{-23} \frac{J}{proton} *3.3*10^{8} \frac{proton}{s} *\frac{60}{1} \frac{s}{minute} *\frac{60}{1} \frac{minute}{hr}](https://tex.z-dn.net/?f=E%3D5.93%2A10%5E%7B-23%7D%20%5Cfrac%7BJ%7D%7Bproton%7D%20%2A3.3%2A10%5E%7B8%7D%20%5Cfrac%7Bproton%7D%7Bs%7D%20%2A%5Cfrac%7B60%7D%7B1%7D%20%5Cfrac%7Bs%7D%7Bminute%7D%20%2A%5Cfrac%7B60%7D%7B1%7D%20%5Cfrac%7Bminute%7D%7Bhr%7D)
E=7.04*10⁻¹¹ ![\frac{J}{hr}](https://tex.z-dn.net/?f=%5Cfrac%7BJ%7D%7Bhr%7D)
The total energy of the photons detected in one hour is 7.04*10⁻¹¹ J
After ionization, sodium gains a net positive charge cuz sodium loses its 1 valence electron to gain the nearest stable octet which is neon{Ne}. Hope it helps
Answer:
-5.51 kJ/mol
Explanation:
Step 1: Calculate the heat required to heat the water.
We use the following expression.
![Q = c \times m \times \Delta T](https://tex.z-dn.net/?f=Q%20%3D%20c%20%5Ctimes%20m%20%5Ctimes%20%5CDelta%20T)
where,
- c: specific heat capacity
- m: mass
- ΔT: change in the temperature
The average density of water is 1 g/mL, so 75.0 mL ≅ 75.0 g.
![Q = 4.184J/g.\°C \times 75.0g \times (95.00\°C - 25.00\°C) = 2.20 \times 10^{3} J = 2.20 kJ](https://tex.z-dn.net/?f=Q%20%3D%204.184J%2Fg.%5C%C2%B0C%20%5Ctimes%2075.0g%20%5Ctimes%20%2895.00%5C%C2%B0C%20-%2025.00%5C%C2%B0C%29%20%3D%202.20%20%5Ctimes%2010%5E%7B3%7D%20J%20%3D%202.20%20kJ)
Step 2: Calculate the heat released by the methane
According to the law of conservation of energy, the sum of the heat released by the combustion of methane (Qc) and the heat absorbed by the water (Qw) is zero
Qc + Qw = 0
Qc = -Qw = -22.0 kJ
Step 3: Calculate the molar heat of combustion of methane.
The molar mass of methane is 16.04 g/mol. We use this data to find the molar heat of combustion of methane, considering that 22.0 kJ are released by the combustion of 64.00 g of methane.
![\frac{-22.0kJ}{64.00g} \times \frac{16.04g}{mol} = -5.51 kJ/mol](https://tex.z-dn.net/?f=%5Cfrac%7B-22.0kJ%7D%7B64.00g%7D%20%5Ctimes%20%5Cfrac%7B16.04g%7D%7Bmol%7D%20%3D%20-5.51%20kJ%2Fmol)