Question

An unknown mass of each of the following substances, initially at 25.0 ∘C , absorbs 1960 J of heat. The final temperature is recorded as indicated. Find the mass of each substance.

Answer 1

The mass of each of the substance, given their final temperature is:

• Mass of glass is 85.7 g
• Mass of ethanol glass is 41.5 g
• Mass of water glass is 64.2 g

How to calculate the mass of each substance?

The mass of the glass can be calculated as follow:

• Initial temperature (T₁) = 25.0 °C
• Heat absorbed (Q) = 1960 J
• Final temperature (T₂) = 55.5 °C
• Change in temperature (ΔT) = 55.5 - 25 = 30.5 °C
• Specific heat capacity of glass (C) = 0.75 J/g°C
• Mass of glass (M) =?

`M = (Q)/(C\Delta T) \\\\M = (1960)/(0.75\ *\ 30.5)\\\\M = 85.7\ g`

The mass of the ethanol can be calculated as follow:

• Initial temperature (T₁) = 25.0 °C
• Heat absorbed (Q) = 1960 J
• Final temperature (T₂) = 44.5 °C
• Change in temperature (ΔT) = 44.5 - 25 = 19.5 °C
• Specific heat capacity of glass (C) = 2.42 J/g°C
• Mass of ethanol glass (M) =?

`M = (Q)/(C\Delta T) \\\\M = (1960)/(2.42\ *\ 19.5)\\\\M = 41.5\ g`

The mass of the water can be calculated as follow:

• Initial temperature (T₁) = 25.0 °C
• Heat absorbed (Q) = 1960 J
• Final temperature (T₂) = 32.3 °C
• Change in temperature (ΔT) = 32.3 - 25 = 7.3 °C
• Specific heat capacity of glass (C) = 4.18 J/g°C
• Mass of water glass (M) =?

`M = (Q)/(C\Delta T) \\\\M = (1960)/(4.18\ *\ 7.3)\\\\M = 64.2\ g`

Complete question:

An unknown mass of each of the following substances, initially at 25.0 ?C, absorbs 1960 J of heat. The final temperature is recorded as indicated. Find the mass of each substance.

a.) Glass (55.5 °C)

b.) Ethanol (44.5 °C)

c.) water (32.3 °C)