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Masja [62]
2 years ago
8

When 1.14 g of octane (molar mass = 114 g/mol) reacts with excess oxygen in a constant volume calorimeter, the temperature of th

e calorimeter increases by 10.0°C. The heat capacity of the calorimeter is 6.97 kJ/°C. Determine the energy flow, q (reaction).
Physics
1 answer:
balandron [24]2 years ago
7 0

Answer:

Q (reaction) = -69.7 kJ

Explanation:

Octane reacts with oxygen to give carbon dioxide and water.

C₈H₁₈ + 25 O₂ ---> 16 CO₂ +18 H₂O

This reaction is exothermic in nature. Therefore, the energy is released into the atmosphere. This reaction took place in a calorimeter, there the temperature (T) increases by 10 C. The heat capacity of the calorimeter is 6.97 kJ/C

The heat (q) of the reaction is calculated as follows:

Q= -cT, where c is the heat capacity of the calorimeter and T is the increase in temperature

q = -(6.97) x (10) = -69.7kJ

<em>Since the heat capacity is given in kilo -joule per degree Celsius, therefore, the mass of octane is not required </em>

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Arisa [49]

Answer:

31.6\:\mathrm{m/s}

Explanation:

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When released, this potential energy will be converted into kinetic energy. Kinetic energy is given by KE=\frac{1}{2}mv^2, where m is the mass of the object and v is the object's velocity.

Thus, we have:

Us=KE,\\\frac{1}{2}kx^2=\frac{1}{2}mv^2

Substituting given values, we get:

\frac{1}{2}\cdot 50\cdot 0.2^2=\frac{1}{2}\cdot 0.002\cdot v^2,\\v^2=\frac{50\cdot 0.2^2}{0.002},\\v^2=1000,\\v\approx \boxed{31.6\:\mathrm{m/s}}

4 0
2 years ago
_________ liquids and gases exert a buoyant force.
Eduardwww [97]

Answer:

C. Both

Explanation:

5 0
2 years ago
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Two Polaroids are aligned so that the initially unpolarized light passing through them is a maximum. At what angle should one of
steposvetlana [31]

To solve this problem it is necessary to apply the law of Malus which describes the change in the Intensity of Light when it crosses a polarized surface.

Mathematically the expression is given as

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I = Final Intensity after pass through the polarizer

\theta= Angle between the polarizer and the light

Since it is sought to reduce the intensity by half the relationship between the two intensities will be given as

\frac{I}{I_0} = \frac{1}{2}

Using the Malus Law we have,

I = I_0 cos^2\theta

cos^2\theta = \frac{I}{I_0}

cos^2\theta = \frac{1}{2}

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Answer:

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they cannot because they contain the same amount of liquid

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\\ \bull\tt\longrightarrow P=\dfrac{V^2}{R}

  • P is power
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\\ \bull\tt\longrightarrow R=\dfrac{V^2}{P}

Hence

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\\ \bull\tt\longrightarrow R\propto \dfrac{1}{P}

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The first bulb has less power hence it has greater filament resistance.

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