Answer: fourth option, 10.8 kJ
Explanation:
The <em>heat of fusion</em>, also named latent heat of fusion, is the amount of heat energy required to change the state of a substance from solid to liquid (at constant pressure).
The data of the <em>heat of fusions</em> of the substances are reported in tables and they can be shown either per mole or per gram of substance.
In this case we have that the<em> heat of fusion for water </em>is reported per mole: <em>6.02 kJ/mole</em>.
The formula to calculate <em>how many kJ of heat (total heat) are needed to completely melt 32.3 g of water, given that the water is at its melting point</em> is:
- Heat = number of moles × heat of fusion
The calculations are:
- number of moles = mass / molar mass
number of moles = 32.3 g / 18.015 g/mol = 1.79 mol
- Heat = 1.79 mol × 6.02 kJ / mol = 10.8 kJ ← answer
Answer:
Explanation:The atomic number of sodium is 11. That is, the number of electrons in sodium is 11. Therefore, a sodium atom will have two electrons in the first shell, eight in the 2nd orbit, and an electron in the 3rd shell.
The volume of a block of lead metal that has a density of 11.3g/mL and weighs 2.10g is 0.186mL.
<h3>How to calculate volume?</h3>
The volume of a substance can be calculated by dividing the mass of the substance by its density. That is;
Volume = mass ÷ density
According to this question, a chemist has a block of lead metal (density is 11.3 g/mL). The block weighs 2.10g.
Volume = 2.10g ÷ 11.3g/mL
Volume = 0.186mL
Therefore, the volume of a block of lead metal that has a density of 11.3g/mL and weighs 2.10g is 0.186mL.
Learn more about volume at: brainly.com/question/18670654
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