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3 years ago

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sebongkah es dengan massa 200 gram memiliki suhu -5 c. jika es tersebut ingin diubah menjadi air yang bersuhu 20 c, berapakah ka

lor yang harus diberikan? (kalor jenis air = 4200 J/kg, kalor jenis es = 2100 J/kg, dan kalor lebur es = 336 KJ/kg)

1 answer:

dlinn [17]3 years ago

5 0

Answer:

$86100\ \text{J}$

Explanation:

m = Massa es = 200 g

$c_w$ = Kalor jenis air = $4200\ \text{J/kg}^{\circ}\text{C}$

$c_i$ = Kalor jenis es = $2100\ \text{J/kg}^{\circ}\text{C}$

$L_f$ = Kalor laten fusi es = $336\ \text{kJ/kg}$

$\Delta T_w$ = Perubahan suhu air = $(20-0)^{\circ}\text{C}$

$\Delta T_i$ = Perubahan suhu es = $(0-(-5))^{\circ}\text{C}$

Panas yang dibutuhkan diberikan oleh

$Q=mc_w\Delta T_w+mL_f+mc_i\Delta T_i\\\Rightarrow Q=m(c_w\Delta T_w+L_f+c_i\Delta T_i)\\\Rightarrow Q=0.2(4200\times (20-0)+336000+2100\times (0-(-5)))\\\Rightarrow Q=86100\ \text{J}$

Panas yang dibutuhkan untuk mencairkan es hingga suhu air yang dibutuhkan adalah $86100\ \text{J}$

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