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11111nata11111 [884]
3 years ago
14

How much heat energy in megajoules is neede to convert 7kilograms of ice at negative 9 degrees to water at 0 degrees celsius

Chemistry
1 answer:
den301095 [7]3 years ago
8 0

Heat_1: Get the ice to 0 degrees

Convert 7 kg to grams

7 kg [1000 grams / 1 kg] = 7000 grams

Heat needed to get the the ice from - 9 to 0

deltat = 0 - -9 = 9 degrees

m = 7000 grams

c = 2.1 joules/gram

Heat_1 = m*c*deltat

Heat_1 = 7000 * 2.1 * 9

Heat_1 = 132,300 joules

Heat_2: Melt the ice.

There is no temperature change. The formula is 333 j/gram

Formula: H = mass * constant

H = 7000 g * 333 J / gram

H = 2331000 joules

Heat_3: Total amount of Joules needed.

2331000 + 132300 = 2 463 300 joules

Convert to Megajoules

2 463 300 joules * 1 megajoule / 1000000 = 2.63 megajoules.

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A first order reaction has a rate constant of 0. 543 at 25°C. Given that the activation energy is 75. 9 kj/mol. Calculate the ra
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The rate constant of first order reaction at 32. 3 °C is 0.343 /s must be less the 0. 543 at 25°C.

First-order reactions are very commonplace. we have already encountered  examples of first-order reactions: the hydrolysis of aspirin and the reaction of t-butyl bromide with water to present t-butanol. every other reaction that famous obvious first-order kinetics is the hydrolysis of the anticancer drug cisplatin.

The value of ok suggests the equilibrium ratio of products to reactants. In an equilibrium combination both reactants and merchandise co-exist. big ok > 1 merchandise are k = 1 neither reactants nor products are desired.

Rate constant K₁  = 0. 543 /s

T₁  = 25°C

Activation energy Eₐ =  75. 9 k j/mol.

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