How many kilojoules are needed to convert 77.5 grams of ice at -8.00°C to water at 95.0°C?

Chemistry

1 answer:

Over [174]3 years ago

7 0

Q=mcθ
m= 0.0775 kg
c= 4184 J·kg−1·K−1.
θ= T(final) - T(initial), 95-(-8)

Q=33398.78 J so kJ divide 1000

= 33.39878 kJ

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4.) The temperature of solid silver increases from 30C to 40C by the addition of 117.5

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Answer:

The mass of silver is 49 g (0.049 kg).

Explanation:

Initial temperature = $30^{o}$ C

Final temperature = $40^{o}$ C

Quantity of heat required = 117.5 J

Specific heat capacity of silver = 0.240 J/g $^{o} C$

mass of the silver can be determined by;

Q = mcΔθ

Where: Q is the quantity of heat required, m is the mass of substance, c is the specific heat capacity of the substance and Δθ is the change in temperature.

So that,

117.5 = m x 0.240 x (40 - 30)

117.5 = m x 0.24 x 10

= 2.4m

m = $\frac{117.5}{2.4}$