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Ksivusya [100]
3 years ago
15

How much heat is released when 35kg of water freezes?

Physics
1 answer:
inn [45]3 years ago
3 0
You need an additional point of data here: the enthalpy of fusion, or conversely the enthalpy of melting (they differ only by their sign). For water (or ice) that value is gotten from sources such as the internet

<span>ΔH°(fus) = 6.01 kJ/mole </span>

<span>Since you have 35 000g, how many moles do you have? </span>
<span>Moles H2O = 35000 g/(18.015 g/mole) = 1942.8 moles</span>

<span>So, take that ΔH°(fus) in kJ/mole, multiply by the number of moles, and there ya go! 
</span>
6.01 x 1942.8 = 11,676 kJ of energy is released

Hope I helped!! xx
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Use the Bohr model to address this question. When a hydrogen atom makes a transition from the 5 th energy level to the 2nd, coun
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Answer:

A. 2.82 eV

B. 439nm

C. 59.5 angstroms

Explanation:

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E_{5,2}=-13.6(\frac{1}{5^2}-\frac{1}{2^2})=2.82eV

B. The energy of the emitted photon is given by the following formula:

E=h\frac{c}{\lambda}   (2)

h: Planck's constant = 6.62*10^{-34} kgm^2/s

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You first convert the energy from eV to J:

2.82eV*\frac{1J}{6.242*10^{18}eV}=4.517*10^{-19}J

Next, you use the equation (2) and solve for λ:

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C. The radius of the orbit is given by:

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hence, the radius of the atom in its 5-th state is 59.5 anstrongs

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