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3 years ago

13

In a chemical reaction, the reactants contain 385 kJ of chemical energy, and the products contain 366 kJ of chemical energy.

2 answers:

miv72 [106K]3 years ago

7 0

In order for energy to be conserved 19 KILO JOULE OF ENERGY MUST BE RELEASED AS HEAT.
In chemical reactions, energy is always conserved. In the question given above, there is a difference of 19 kj in the energy quantity between the reactants and the products. The reactants has more energy than the products, this excess energy is given off as heat during the reaction.

andrezito [222]3 years ago

6 0

Answer: 19kJ of energy must be released

Explanation:

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5.0g of aluminum fluoride decomposes into aluminum and oxygen. What mass of oxygen is formed?

frutty [35]

Answer:

5

Explanation:

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3 years ago

Be sure to answer all parts. In the average adult male, the residual volume (RV) of the lungs, the volume of air remaining after

Alenkinab [10]

<u>Answer:</u>

<u>For a:</u> The number of moles of air present in the RV is 0.047 moles

<u>For b:</u> The number of molecules of gas is $2.83\times 10^{22}$

<u>Explanation:</u>

<u>For a:</u>

To calculate the number of moles, we use the equation given by ideal gas follows:

$PV=nRT$

where,

P = pressure of the air = 1.00 atm

V = Volume of the air = 1200 mL = 1.2 L (Conversion factor: 1 L = 1000 mL)

T = Temperature of the air = $37^oC=[37+273]K=310K$

R = Gas constant = $0.0821\text{ L. atm }mol^{-1}K^{-1}$

n = number of moles of air = ?

Putting values in above equation, we get:

$1.00atm\times 1.2L=n_{air}\times 0.0821\text{ L atm }mol^{-1}K^{-1}\times 310K\\n_{air}=\frac{1.00\times 1.2}{0.0821\times 310}=0.047mol$

Hence, the number of moles of air present in the RV is 0.047 moles

<u>For b:</u>

According to mole concept:

1 mole of a compound contains $6.022\times 10^{23}$ number of molecules.

So, 0.047 moles of air will contain $(0.047\times 6.022\times 10^{23})=2.83\times 10^{22}$ number of gas molecules.

Hence, the number of molecules of gas is $2.83\times 10^{22}$

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3 years ago

What is very fine sediment called

Alecsey [184]

Loess, which can be carried by wind over long distances.

4 0

3 years ago

Read 2 more answers

The molarity of a 2 liter aqueous solution that contains 222.2 grams of dissolved calcium chloride ( CaCl2), expressed with two

sveta [45]

Answer:

The answer to your question is 1 M

Explanation:

Data

Molarity = ?

mass of CaCl₂ = 222.2 g

Volume = 2 l

Process

1.- Calculate the molar mass of CaCl₂

CaCl₂ = 40 + (35.5 x 2) = 40 + 71 = 111 g

2.- Calculate the moles of CaCl₂

111g of CaCl₂ ---------------- 1 mol

222.2 f of CaCl₂ ---------------- x

x = (222.2 x 1) / 111

x = 222.2 / 111

x = 2 moles

3.- Calculate the Molarity

Molarity = moles / Volume

-Substitution

Molarity = 2/2

-Result

Molarity = 1

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4 years ago

Find the hydroxide ion concentration of a HBr solution with a pH of 4.75

Sunny_sXe [5.5K]

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4 years ago