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3 years ago

What source provides most of the energy consumed in the United States?

Chemistry

1 answer:

umka2103 [35]3 years ago

4 0

Answer:

Fossil fuels

Explanation:

Fossil fuels — natural gas, coal, and petroleum, and — provide most (63 %) of the energy consumed in the United States

The breakdown in 2019 was

Natural gas 38 %

Coal 24 %

Petroleum 1 %

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Question about thermodynamics

Fiesta28 [93]

Answer:

Thermodynamics is the branch of physics that deals with the relationships between heat and other forms of energy.

4 0

3 years ago

Write a balanced equation for the complete combustion of propane, C3H8 . Do not enter phase symbols. Enter the alkane formula as

Anastaziya [24]

Answer:

C3H8 + 5O2 => 3CO2 + 4H2O

Explanation:

Hydrocarbon combustion is the reaction between a hydrocarbon and O2 producing CO2 and water.

C3H8 + O2 => CO2 + H2O

First we balance the C and H.

C3H8 + O2 => 3CO2 + 4H2O

Now we balance O for the answer!

C3H8 + 5O2 => 3CO2 + 4H2O

3 0

3 years ago

Copper metal (Cu) reacts with silver nitrate (AgNO3) in aqueous solution to form Ag and Cu(NO3)2. The balanced chemical equation

Rufina [12.5K]

The mass formed in a chemical reaction is given by stoichiometry law in balanced chemical equation. The mass of silver produced in the reaction is 107. 9 g.

<h3>What is the stoichiometric law?</h3>

The stoichiometric law states that in a balanced chemical equation, the stoichiometric coefficient describes the moles of each compound in a chemical reaction.

The balanced chemical equation for the reaction is:

$\rm Cu\;+\;2\;AgNO_3\;\rightarrow\;Cu(NO_3)_2\;+\;2\;Ag$

From the balanced chemical equation, 1 moles of copper results in 2 moles of silver.

Moles in terms of mass can be given as:

$\rm Moles=\dfrac{Mass}{Molar\;mass}$

Thus, moles of 31. 75 grams copper is:

$\rm Cu=\dfrac{ 31. 75 }{63.5}\;mol\\ Cu=0.5 mol$

The moles of Ag produced can be given from stoichiometric law as:

$\rm 1\;mol\;Cu=2\;mol\;Ag\\0.5 \;mol\;Cu=0.5\;\times\;2\;mol\;Ag\\0.5\;mol\;Cu=1\;mol\;Ag$

The moles of Ag produced is 1 mol.

The mass of a mole of element is equivalent to the molar mass. Thus, the mass of Ag produced in the reaction is 107. 9 g. Hence, option B is correct.

Learn more about stoichiometric law, here:

brainly.com/question/6907332

7 0

2 years ago

For many weak acid or weak base calculations, you can use a simplifying assumption to avoid solving quadratic equations. Classif

shtirl [24]

Answer:

a. not valid

b. valid

c. not valid

d. valid

e. not valid

Explanation:

The assumption to avoid solving the quadratic equation for the calculation of [H⁺] and [OH⁻] involved in the equilibria of weak acids and bases ( small Ka and Kb) is valid as long as the value obtained from the shortcut is less than 5 % or less of the original acid or base concentration.

For a general monoprotic acid, as in this question, the equlibria is:

HA + H₂O ⇄ H₃O⁺ + A⁻ Ka = [H₃O⁺][A⁻]/[HA]

To determine the concentrations at equilibrium we are going to setupup the ICE table:

[HA] [H₃O] [A⁻]

Initial [HA]₀ 0 0

Change - x +x +x

Equil [HA]₀ - x x x

Ka = x² / [HA]₀ - x

Here is where we make our simplification of approximating [HA]₀ - x to the original acid concentration, [HA]₀, assuming x is much less than [HA] since HA is a weak acid.

To answer our questions we will solve for x,and then can compare it to the initial HA concentration.

Lets now perform our calculations.

(a) x = √ (0.01 x 1x 10⁻⁴) = 1 x 10⁻³ M = [H₃O⁺]

% = 1 x 10⁻³/.01 x 100 = 10%

The assumption is not valid.

(b) x = √ (0.01 x 1x 10⁻⁵) = 3.2 x 10⁻⁴ M = [H₃O⁺]

% = 3.2 x 10⁻⁴ /0.01 x 100 = 3.2 %

The assumption is valid since the criteria of 5 % or less has been met.

% = 1.0 x 10⁻² /0.1 x 100 = 10 %

The assumption is not valid, we wiould have to solve the quadratic equation.

(d) x = √ (1 x 1x 10⁻³) = 3.2 x 10⁻² M = [H₃O⁺]

% = 3.2 x 10⁻² / 1 x 100 = 3.2

The assumption is valid.

(e) x = √ (0.001 x 1x 10⁻⁵) =1.0 x 10⁻⁴ M = [H₃O⁺]

% = 1.0 x 10⁻⁴ / .001 = 10 %

The assumption is not valid and one has to solve the quadratic equation.

7 0

3 years ago

How many atoms of iron are there in 2.5 moles of wolframite

Shalnov [3]

There are 1739218 atoms in 2.5 mole of wolframite

7 0

4 years ago