Suppose that 25 g of each substance is initially at 27.0 °c. what is the final temperature of each substance upon absorbing 2.35 kj of heat?

a. gold

b. silver

Respuesta :

Answer:

a. gold : 755.7°C.

b. silver: 418.7°C.

Explanation:

a. gold :

  • It is known that:

The amount of heat absorbed by gold = Q = m.c.ΔT.

where, m is the mass of Au (m = 25.0 g).

c is the specific heat capacity of Au = 0.129 J/g°C.

ΔT is the temperature difference = (final T - 27.0°C).

Q = 2.35 kJ = 2350.0 J.

∴ The amount of heat absorbed by Au = Q = m.c.ΔT = 2350.0 J.

∴ 2350.0 J = (25.0 g)(0.129 J/g°C)(final T - 27.0°C).

∴ 2350.0 J = 3.225 final T - 87.08.

∴ 3.225 final T = 2350.0 + 87.08 = 2473.

∴ final T = 2473/3.225 = 755.7°C.

b. silver:

  • It is known that:

The amount of heat absorbed by silver = Q = m.c.ΔT.

where, m is the mass of Ag (m = 25.0 g).

c is the specific heat capacity of Ag = 0.24 J/g°C.

ΔT is the temperature difference = (final T - 27.0°C).

Q = 2.35 kJ = 2350.0 J.

∴ The amount of heat absorbed by Ag = Q = m.c.ΔT = 2350.0 J.

∴ 2350.0 J = (25.0 g)(0.24 J/g°C)(final T - 27.0°C).

∴ 2350.0 J = 6.0 final T - 162.0.

∴ 6.0 final T = 2350.0 + 162.0 = 2512.

∴ final T = 2512/6.0 = 418.7°C.

The final temperature of the gold when it absorbs the heat is 755.68 ⁰C.

The  final temperature of the silver when it absorbs the heat is 418.67  ⁰C.

The given parameters;

  • mass of each substance = 25 g
  • initial temperature of each substance = 27 ⁰C
  • specific heat capacity of gold, = 0.129 J/ g⁰C
  • specific heat capacity of silver, 0.24 J/ g⁰C

The final temperature of the gold when it absorbs 2,350 J;

Q = mcΔt

[tex]2350 = 25 \times 0.129 \times (t- 27)\\\\2350 = 3.225t - 87.075\\\\3.225t = 2437.075 \\\\t = \frac{2437.075}{3.225} \\\\t = 755.68 \ ^0c[/tex]

The final temperature of the silver when it absorbs 2,350 J;

Q = mcΔt

[tex]2350 = 25 \times 0.24 \times (t -27)\\\\2350 = 6t - 162\\\\6t = 2350 + 162\\\\6t = 2512\\\\t = \frac{2512}{6} \\\\t = \frac{2512}{6} \\\\t = 418.67 \ ^0C[/tex]

Learn more here:https://brainly.com/question/12411278