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3 years ago

In the chemical reaction: zn(s) + cu2+(aq) → zn2+(aq) + cu(s),

1 answer:

7 0

Zn⁰(s) + Cu²⁺(aq) → Zn²⁺(aq) + Cu⁰(s),

Zn⁰(s) ------> Zn²⁺(aq) + 2e⁻
As we can see Zn(s) lost 2 electrons and became Zn²⁺ ion.
So, Zn was oxidized.
Correct answer is 1) Zn(s).

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How do you calculate the number of photons having a wavelength of 10.0 micrometers required to produce 1.0 kilojoules of energy

shtirl [24]

To calculate this,

We know that energy is 1 photon
E = hc/wavelenth
wavelength of 10.0 m

Solution:
h = 6.626 x 10^-34 Jsec
C = 2.9979 x 10^8 m/sec
E = 6.626 10^-34 * 2.9979 10^8 / 10 = 1.9864 10^-26J

Then, the number of photons is computed by:

n = 1000 / 1.9864 10^-26 = 5.04 10^28 photons

4 0

3 years ago

Explain how deforestation can cause a disruption to the carbon cycle

TEA [102]

Trees and forest play an important role in balancing the amount of Carbon in the atmosphere through the process of photosynthesis where plants make their own food with carbon dioxide, using energy from the sunlight. Therefore, deforestation (cutting down of trees) has an effect on the carbon cycle also the greenhouse gas effect and global warming. Deforestation reduces the removal component of this cycle, thus, increasing the carbon dioxide in the air.

7 0

4 years ago

Sulfur dioxide, SO 2 ( g ) , can react with oxygen to produce sulfur trioxide, SO 3 ( g ) , by the reaction 2 SO 2 ( g ) + O 2 (

aleksley [76]

Answer: The amount of heat produced by the reaction is -21.36 kJ

Explanation:

Enthalpy change is defined as the difference in enthalpies of all the product and the reactants each multiplied with their respective number of moles.

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

$\Delta H^o_{rxn}=\sum [n\times \Delta H_f_{(product)}]-\sum [n\times \Delta H_f_{(reactant)}]$

For the given chemical reaction:

$2SO_2(g)+O_2(g)\rightarrow 2SO_3(g)$

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

$\Delta H_{rxn}=[(2\times \Delta H_f_{(SO_3(g))})]-[(2\times \Delta H_f_{(SO_2(g))})+(1\times \Delta H_f_{(O_2(g))})]$

We are given:

$\Delta H_f_{(SO_2(g))}=-296.8kJ/mol\\\Delta H_f_{(SO_3(g))}=-395.7kJ/mol\\\Delta H_f_{(O_2(g))}=0kJ/mol$

Putting values in above equation, we get:

$\Delta H_{rxn}=[(2\times (-395.7))]-[(2\times (-296.8))+(1\times (0))]\\\\\Delta H_{rxn}=-197.8kJ/mol$

To calculate the number of moles, we use ideal gas equation, which is:

$PV=nRT$

where,

P = pressure of the gas = 1.00 bar

V = Volume of the gas = 2.67 L

n = number of moles of gas = ?

R = Gas constant = $0.0831\text{ L. bar }mol^{-1}K^{-1}$

T = temperature of the mixture = $25^oC=[25+273]K=298K$

Putting values in above equation, we get:

$1.00bar\times 2.67L=n\times 0.0831\text{ L. bar }mol^{-1}K^{-1}\times 298K\\\\n=\frac{1\times 2.67}{0.0831\times 298}=0.108mol$

To calculate the heat released of the reaction, we use the equation:

$\Delta H_{rxn}=\frac{q}{n}$

where,

q = amount of heat released = ?

n = number of moles = 0.108 moles

$\Delta H_{rxn}$ = enthalpy change of the reaction = -197.8 kJ/mol

Putting values in above equation, we get:

$-197.8kJ/mol=\frac{q}{0.108mol}\\\\q=(-197.8kJ/mol\times 0.108mol)=-21.36kJ$

Hence, the amount of heat produced by the reaction is -21.36 kJ

3 0

3 years ago

A 3.82-g sample of magnesium nitride is reacted with 7.73 g of water. mg3n2 (s) + 3 h2o (â) â 2 nh3 (g) + 3 mgo (s) the yield of

horrorfan [7]

The reaction is properly written as

Mg₃N₂ (s) + 3 H₂O (l) --> 2 NH₃ (g) + 3 MgO (s)

Molar mass of Mg₃N₂ = 100.95 g/mol
Molar mass of H₂O = 18 g/mol
Molar mass of MgO = 40.3 g/mol

Moles Mg₃N₂: 3.82/100.95 = 0.0378
Moles H₂O: 7.73/18 = 0.429

Theo H₂O required for available Mg₃N₂: 0.0378*3/1 = 0.1134 mol
Hence, the limiting reactant is Mg₃N₂.
Thus,

Theoretical Yield = 0.0378 mol Mg₃N₂ * 3 mol MgO/Mg₃N₂ * 40.3 g/mol
Theo Yield = 4.57 g

Percent Yield = Actual Yield/Theo Yield * 100
Percent Yield = 3.60 g/4.57 g * 100 = 78.77%

5 0

3 years ago

Cobalt-60 and iodine-131 are radioactive isotopes that are used in

svlad2 [7]

Cobalt 60-Used to treat certain types of cancer.
Iodine-131-Used to monitor and treat goiter and other thyroid problems.It is also used to treat liver and brain tumor
Mark me as the Brainliest❤️❤️✌✌

8 0

3 years ago