How much heat is required to change temperature of 10 g of water from 4 °C to 8 °C? (Water has a specific heat of 4.18 )?
1 answer:
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Answer:
3.48 g NaF
Explanation:
Dimensional Analysis:
Answer (Simplifying the Expression Above):
3.48 g NaF
This problem is providing the heating curve of ethanol showing relevant data such as the initial and final temperature, melting and boiling points, enthalpies of fusion and vaporization and specific heat of solid, liquid and gaseous ethanol, so that the overall heat is required and found to be 1.758 kJ according to:
<h3>Heating curves:</h3>In chemistry, we widely use heating curves in order to figure out the required heat to take a substance from a temperature to another. This process may involve sensible heat and latent heat, when increasing or decreasing the temperature and changing the phase, respectively.
Thus, since ethanol starts off solid and end up being a vapor, we will find five types of heat, three of them related to the heating-up of ethanol, firstly solid, next liquid and then vapor, and the other two to its fusion and vaporization as shown below:
Hence, we begin by calculating each heat as follows, considering 1 g of ethanol is equivalent to 0.0217 mol:
Finally, we add them up to get the result:
Learn more about heating curves: brainly.com/question/10481356
Answer:
Explanation:
Diethyl malonate is more acidic than monocarbonyl compounds (pKa=13) due to their alpha hydrogens being attached to two carbonyl groups. Thus, the <u>malonic ester is easily converted to its enolate ion by reaction with sodium ethoxide in ethanol</u>. The product of the alkylation of the malonic ester leaves a <u>hydrogen atom acid in an alpha position</u>, so the alkylation process can be repeated a second time to produce a dialkylated malonic ester.
In this case, when urea is treated with diethyl malonate in the presence of sodium ethoxide base,<u> the second alkylation step occurs intramolecularly</u> to generate a cyclic product, barbituric acid.
