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4 years ago

Ultraviolet radiation has a frequency of 6.8×1015 Hz. What is the energy associated with this frequency?

1 answer:

5 0

Use Planck's equation (E=hv) to solve. where <span>frequency (v) of ultrviolet radiation is 6.8 × 1015 1/s. </span><span> </span>The variable h is a constant equal to 6.63 × 10-34 J·s
E= <span>(6.8 × 1015 1/s)x(</span>6.63 × 10-34 J·s)

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Balance the equations by inserting coefficients as needed.

ASHA 777 [7]

Answer:

1. CaCO3 + 2HCl → CaCl2 + H2O + CO2

2. C6H12O2 + 8O2 → 6CO2 + 6H2O

Explanation:

7 0

4 years ago

Read 2 more answers

Taro plants, which are native to Africa, were introduced into Florida's wetland biome in 1910. Today taro plants grow wild in th

Wewaii [24]

The answer would be b hope it helps

6 0

3 years ago

How many Moles of NAOH are present in 2.50L of 0.300 M NaOH?

maw [93]

<h3>Answer:</h3>

0.75 moles NaOH

<h3>Explanation:</h3>

We are given;

Volume of NaOH solution = 2.5 Liters

Molarity of NaOH = 0.300 M

We are required to calculate the moles of NaOH

We need to establish the relationship between moles, molarity and volume of a solution.

That would be;

Concentration/molarity = Moles ÷ Volume

Therefore;

Moles = Concentration × Volume

Thus;

Moles of NaOH = 0.300 moles × 2.50 L

= 0.75 moles

Therefore, the number of moles of NaOH is 0.75 moles

8 0

4 years ago

I2(g) + Cl2(g)2ICl(g) Using standard thermodynamic data at 298K, calculate the entropy change for the surroundings when 1.62 mol

galina1969 [7]

Answer:

The change in entropy of the surrounding is -146.11 J/K.

Explanation:

Enthalpy of formation of iodine gas = $\Delta H_f_{(I_2)}=62.438 kJ/mol$

Enthalpy of formation of chlorine gas = $\Delta H_f_{(Cl_2)}=0 kJ/mol$

Enthalpy of formation of ICl gas = $\Delta H_f_{(ICl)}=17.78 kJ/mol$

The equation used to calculate enthalpy change is of a reaction is:

$\Delta H_{rxn}=\sum [n\times \Delta H_f(product)]-\sum [n\times \Delta H_f(reactant)]$

For the given chemical reaction:

$I_2(g)+Cl_2(g)\rightarrow 2ICl(g),\Delta H_{rxn}=?$

The equation for the enthalpy change of the above reaction is:

$\Delta H_{rxn}=[(2\times \Delta H_f_{(ICl)})]-[(1\times \Delta H_f_{(I_2)})+(1\times \Delta H_f_{(Cl_2)})]$

$=[2\times 17.78 kJ/mol]-[1\times 0 kJ/mol+1\times 62.436 kJ/mol]=-26.878 kJ/mol$

Enthaply change when 1.62 moles of iodine gas recast:

$\Delta H= \Delta H_{rxn}\times 1.62 mol=(-26.878 kJ/mol)\times 1.62 mol=-43.542 kJ$

Entropy of the surrounding = $\Delta S^o_{surr}=\frac{\Delta H}{T}$

$=\frac{-43.542 kJ}{298 K}=\frac{-43,542 J}{298 K}=-146.11 J/K$

1 kJ = 1000 J

The change in entropy of the surrounding is -146.11 J/K.

4 0

3 years ago

The lowest value of the henry's law for methane gas (ch4) will be obtained with __________ as the solvent and a temperature of _

NikAS [45]

The lowest value of the henry's law for methane gas (CH₄) will be obtained with H₂O as the solvent and a temperature of 349 K.

Henry's law: This law states that at a constant temperature, the amount of a gas dissolved in a given type and volume of liquid is directly proportional to the partial pressure of that gas that in equilibrium with that liquid.

Mathematically it can be written as:

$C_{g}=k\times P_{g}$

So, for the methane gas , lowest value of the henry's law obtained at 349 K and with H₂O as the solvent.

3 0

3 years ago