Calculate the mass of magnesium needed to make 25g of magnesium oxide

Five kilograms of liquid carbon tetrachloride undergo a mechanically reversible, isobaric change of state at 1 bar during which

Drupady [299]

Answer:

Explanation:

From the information given:

Mass of carbon tetrachloride = 5 kg

Pressure = 1 bar

The given density for carbon tetrachloride = 1590 kg/m³

The specific heat of carbon tetrachloride = 0.84 kJ/kg K

From the composition, the initial volume of carbon tetrachloride will be: $= \dfrac{5 \ kg }{1590 \ kg/m^3}$

= 0.0031 m³

Suppose $\beta$ is independent of temperature while pressure is constant;

Then:

The change in volume can be expressed as:

$\int ^{V_2}_{V_1} \dfrac{dV}{V} =\int ^{T_2}_{T_1} \beta dT$

$In ( \dfrac{V_2}{V_1}) = \beta (T_2-T_1)$

$V_2 = V_1 \times exp (\beta (T_2-T_1))$

$V_2 = 0.0031 \ m^3 \times exp (1.2 \times 10^{-3} \times 20)$

$V_2 = 0.003175 \ m^3$

However; the workdone = -PdV

$W = -1.01 \times 10^5 \ Pa \times ( 0.003175 m^3 - 0.0031 \ m^3)$

W = - 7.6 J

The heat energy Q = Δ h

$Q = mC_p(T_2-T_1)$

$Q = 5 kg \times 0.84 \ kJ/kg^0 C \times 20$

Q = 84 kJ

The internal energy is calculated by using the 1st law of thermodynamics; which can be expressed as;

ΔU = ΔQ + W

ΔU = 84 kJ + ( -7.6 × 10⁻³ kJ)

ΔU = 83.992 kJ

3 0

3 years ago

Write 4.13X10^3 in decimal notation.

alukav5142 [94]

Answer:

4.13X10^3= 4130 in the expanded form

4 0

3 years ago

What do noble gases all have in common?

erastova [34]

Answer:

D. They react readily with oxygen in the air

3 0

2 years ago

a serving of a particular fruit dessert contains 20.0 g of sugar. if all the sugar is sucrose, c12h22o11, how many molecules of

Harrizon [31]

Taking into account the definition of Avogadro's number and molar mass, 3.49334×10²² molecules of sucrose are present.

<h3>Definition of molar mass</h3>

The molar mass of substance is a property defined as its mass per unit quantity of substance, in other words, molar mass is the amount of mass that a substance contains in one mole.

<h3>Avogadro's Number</h3>

Avogadro's Number or Avogadro's Constant is called the number of particles that make up a substance (usually atoms or molecules) and that can be found in the amount of one mole of said substance. Its value is 6.023×10²³ particles per mole. Avogadro's number applies to any substance.

<h3>Molecules of sugar in this case</h3>

In first place, the molar mass of sucrose is 342 g/mole. So, you can apply the following rule of three: If by definition of molar mass 342 grams of the compound are contained in 1 mole, 20 grams of the compound are contained in how many moles?

$amount of moles=\frac{20 gramsx1 mole}{342 grams}$

<u><em>amount of moles= 0.058 moles</em></u>

Now, considering the Avogadro's number, you can apply the following rule of three: If 1 mole of the compound contains 6.023×10²³ molecules, 0.058 moles contains how many molecules?

amount of moleculas= (6.023×10²³ molecules × 0.058 moles)÷ 1 mole

<u><em>amount of molecules= 3.49334×10²² molecules</em></u>

Finally, 3.49334×10²² molecules of sucrose are present.

Learn more about

molar mass:

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Avogadro's Number:

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