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3 years ago

How much H2 is generated from the electrolysis of 150 grams of H2O

Chemistry

1 answer:

Romashka [77]3 years ago

5 0

Answer:

16.67 grams of H₂ is generated from the electrolysis of 150 grams of H₂O

Explanation:

Electrolysis is the decomposition of a chemical element under the effect of an electric current. So, electrolysis of water is the process of decomposing the H₂O molecule into separate oxygen and hydrogen gases due to an electric current passing through the water.

The balanced equation of electrolysis of water is:

2 H₂O → O₂ + 2H₂

Being:

H: 1 g/mole
O: 16 g/mole

then the molar mass of the compounds that participate in the reaction is:

H₂O: 2*1 g/mole + 16 g/mole= 18 g/mole
H₂: 2*1 g/mole= 2 g/mole
O₂: 2*16 g/mole= 32 g/mole

If the following amounts in moles are reacted by stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction):

H₂O: 2 moles
H₂: 2 moles
O₂: 1 mole

the amount of mass, by stoichiometry, that reacts and is produced is:

H₂O: 2 moles*18 g/mole=36 g
H₂: 2 moles* 2 g/mole= 4 g
O₂: 1 mole* 32 g/mole= 32 g

Then you can apply the following rule of three: if by stoichiometry 36 g of H₂O generate 4 g of H₂, 150 g of H₂O how much mass of H₂ will it generate?

$massofH_{2} =\frac{150 grams of H_{2}O*4 grams ofH_{2} }{36 grams of H_{2}O}$

mass of H₂= 16.67 grams

16.67 grams of H₂ is generated from the electrolysis of 150 grams of H₂O

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Explanation: Boiling and Evaporation: Evaporation is the change of a substance from a liquid to a gas. Boiling is the change of a liquid to a vapor, or gas, throughout the liquid.

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1 year ago

When sugar dissolves in water are covalent bonds broken?

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3 years ago

6. An environmental chemist needs a carbonate buffer of pH 10.00 to study the effects of acid rain on limestone-rich soils. To p

pishuonlain [190]

Answer:

[Na₂CO₃] = 0.094M

Explanation:

Based on the reaction:

HCO₃⁻(aq) + H₂O(l) ↔ CO₃²⁻(aq) + H₃O⁺(aq)

It is possible to find pH using Henderson-Hasselbalch formula:

pH = pka + log₁₀ [A⁻] / [HA]

Where [A⁻] is concentration of conjugate base, [CO₃²⁻] = [Na₂CO₃] and [HA] is concentration of weak acid, [NaHCO₃] = 0.20M.

pH is desire pH and pKa (10.00) is -log pka = -log 4.7x10⁻¹¹ = 10.33

Replacing these values:

10.00 = 10.33 + log₁₀ [Na₂CO₃] / [0.20]

[Na₂CO₃] = 0.094M

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3 years ago

When the following equation is balanced using the smallest possible integers, what is the coefficent of oxygen gas?

elena55 [62]

By balancing a chemical reaction, you must first balance the atom that is in smaller amount in the chemical species that you have in the reaction. In the combustion reaction presented in the question that atom is carbon (C). Therefore, the first thing to do is multiply the CO2 by 7, since those are the carbon atoms that are in the C7H16O. The reaction would be like this,

C7H16O + O2 → 7CO2 + H2O

You can make a table of the amount of atoms of C, H and O that you have in the reagents and products after you put a coefficient 7 in front of the CO2, in the following way,

R P

C 7 7

H 16 2

O 3 15

Then you balance the hydrogens. It is better that you leave the last oxygens since there is an oxygen molecule alone, so when adding a coefficient to balance it, the quantities of the rest of the atoms in the equation would not be altered.

To balance the hydrogens you add an 8 in front of the H2O molecule in the reagents, since there are 16 hydrogens in the molecule C7H16O and

8H x 2H = 16H.

The reaction and the table would be like this,

C7H16O + O2 → 7CO2 + 8H2O

R P

C 7 7

H 16 16

O 3 22

Finally, you balance the atoms of O. To do this, you add a coefficient of 21/2 to the O2 molecule, this is because (21/2) x2 = 21 and 21 O coming from the O2 molecule plus an O coming from the C7H16O molecule gives a total of 22 O, which are equal to the amount of O we have in the products.

C7H16O + (21/2)O2 → 7CO2 + 8H2O

To bring the coefficients of the reactants and the products to whole numbers multiply all the coefficients by 2. Then the reaction is like,

2 C7H16O + 21O2 → 14CO2 + 16H2O

As you can see when the given reaction is balanced using the smallest possible integers, the coefficent of oxygen gas is 21

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4 years ago

Determine the mass of KNO3 that dissolves in 100 grams of water at 40°C to produce a saturated solution

velikii [3]

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That means that 100 g of water at 40°C can dissolve 63 g of KNO3.

A saturated solution is one that cannot dissolve more solute, because it already has reached the greatest concentration that it can hold.

Then, the mass of KNO3 that dissolves in 100 g of water is about 63 g.

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3 years ago