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Topic: Measuring and calculating molar heat of solution- Please Help?  (Read 2507 times)

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Offline tonigerco

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Measuring and calculating molar heat of solution- Please Help?
« on: September 27, 2016, 10:52:11 PM »
Is the following reaction exothermic or endothermic? Explain.

NaOH(s) -----> Na+(aq) + OH–(aq)

Offline tonigerco

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Measuring and calculating molar heat of solution- Please Help?
« Reply #1 on: September 27, 2016, 10:52:46 PM »
A student wants to measure the heat of
solution of sodium hydroxide. To do this,
he places 100 g of water in a beaker. The
temperature of the water is 15°C. He
weighs out 10.0 g of solid sodium
hydroxide. He pours all of this into the
water in the cup, stirs to help the solid to
dissolve, and measures the maximum
temperature reached by the mixture as
38°C.

Use the equation ΔH = –mCΔT to calculate the amount heat given off by dissolving
the sodium hydroxide in 100 g of water.
Note: The specific heat of water is 4.18 J g–1 °C–1.

Use your answer from (a) to show that the heat of solution of sodium hydroxide is –38
kJ mol–1. The molar mass of sodium hydroxide is 40.0 g.

Offline Borek

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Re: Measuring and calculating molar heat of solution- Please Help?
« Reply #2 on: September 28, 2016, 02:49:29 AM »
You have to show your attempts at solving the problem, this is a forum policy.
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Offline Vidya

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Re: Measuring and calculating molar heat of solution- Please Help?
« Reply #3 on: September 29, 2016, 12:20:36 AM »
Is the following reaction exothermic or endothermic? Explain.

NaOH(s) -----> Na+(aq) + OH–(aq)
when you dissolved NaOH in water then what happens to the temperature of water ...rises or goes down ?
based on it you can decide if it is exothermic or endothermic.

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