Exploring Phase Change Energy Problems

The video tutorial explains phase changes in water, focusing on energy constancy during transitions from solid to liquid and liquid to gas. It covers calculations for heating ice from -20°C to 0°C, heating water from 0°C to 100°C, and boiling water to steam. The tutorial emphasizes the importance of understanding specific heat and phase change energy requirements, using equations like Q=MCΔT, heat of fusion, and heat of vaporization.

What happens to the energy of water when it changes from a solid to a liquid?

• It fluctuates.

• It increases.

• It decreases.

• It stays constant.

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At what temperature does ice start to melt?

• 50°C

• -20°C

• 100°C

• 0°C

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What is the specific heat of ice used in the calculation?

• 3.00 J/g°C

• 1.00 J/g°C

• 2.03 J/g°C

• 4.184 J/g°C

How much energy is required to warm 30 grams of ice from -20°C to 0°C?

• 2000 J

• 1500 J

• 1000 J

• 1218 J

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NGSS.MS-PS1-4

What is the specific heat of liquid water used in the calculation?

• 1.00 J/g°C

• 3.00 J/g°C

• 2.03 J/g°C

• 4.184 J/g°C

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NGSS.MS-PS3-3

How much energy is needed to warm 100 grams of water from 0°C to 100°C?

• 41840 J

• 401840 J

• 10000 J

• 4184 J

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NGSS.MS-PS1-4

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What is the heat of vaporization used in the calculation?

• 2260 J/g

• 334 J/g

• 4184 J/g

• 1000 J/g

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NGSS.MS-PS1-4

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How much energy is needed to completely boil away 35 grams of water at 100°C?

• 50000 J

• 100000 J

• 79100 J

• 200000 J

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NGSS.MS-PS1-4

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What is the total energy required to take 45 grams of ice at -10°C to steam at 100°C?

• 200000 J

• 50000 J

• 100000 J

• 136471.5 J

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NGSS.MS-PS1-4

NGSS.MS-PS3-4

Which equation is used to calculate the energy required for a temperature change?

• Q = mcΔT

• Q = mL

• Q = mH

• Q = mC