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2 years ago

Suppose a snack bar is burned in a calorimeter and heats 2,000 g water by 20 °C. How much heat energy was released?

Chemistry

1 answer:

prohojiy [21]2 years ago

7 0

Heat energy released : 167.2 kJ

<h3>Further explanation</h3>

Heat can be calculated using the formula:

Q = mc∆T

Q = heat, J

m = mass, g

c = specific heat, joules / g ° C

∆T = temperature difference, ° C / K

m = 2000 g

c = 4.18 J/ g ° C

∆t = 20 ° C

$\tt Q=2000\times 4.18\times 20\\\\Q=167200~J=167.2~kJ$

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In this case, as water sits in an open beaker it tends to evaporate thereby forming water vapor. This vapor phase then exerts a pressure over the liquid water, which is termed as the vapor pressure of water at that temperature and pressure. As water continues to evaporate, more and more molecules escape into the vapor phase which thereby increases the vapor pressure.

Ans: The vapor pressure of water increases as the water evaporates.

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3 years ago

A typical refrigerator is kept at 4˚C, and a soda can has a pressure of

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Answer: The new pressure will be 1.42 atm

Explanation:

To calculate the final pressure of the system, we use the equation given by Gay-Lussac Law. This law states that pressure of the gas is directly proportional to the temperature of the gas at constant pressure.

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2 years ago

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3 years ago

The coolant in automobiles is often a 50/50 % by volume mixture of ethylene glycol, C2H6O2, and water. At 20°C, the density of e

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= $\frac{density \times volume}{molar mass}$

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Thus, we can conclude that the expected freezing point is $-33.31^{o}C$ .

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2 years ago

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3 years ago

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