Answer:
invalid
Explanation:
Just imagine doing this experiment MULTIPLE TIMES and one of the trials you get 72 Kcal while in another u get 12kcal. It doesn't make sense. Somewhere in the experiment she went wrong. So its invalid
Mole-mole calculations are not the only type of calculations that can be performed using balanced chemical equations. Recall that the molar mass can be determined from a chemical formula and used as a conversion factor. We can add that conversion factor as another step in a calculation to make a mole-mass calculation, where we start with a given number of moles of a substance and calculate the mass of another substance involved in the chemical equation, or vice versa.
For example, suppose we have the balanced chemical equation
2 Al + 3 Cl 2 → 2 Alcoa
Suppose we know we have 123.2 g of Cl 2. How can we determine how many moles of Alcoa we will get when the reaction is complete? First and foremost, chemical equations are not balanced in terms of grams; they are balanced in terms of moles. So to use the balanced chemical equation to relate an amount of Cl 2 to an amount of Alcoa, we need to convert the given amount of Cl 2 into moles. We know how to do this by simply using the molar mass of Cl 2 as a conversion factor. The molar mass of Cl 2 (which we get from the atomic mass of Cl from the periodic table) is 70.90 g/mil. We must invert this fraction so that the units cancel properly:
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
No, they do not. Hope I helped! :)
Answer:(d) has a high melting point because it has a giant covalent structure ... (i) Calculate the maximum mass of propyl ethanoate that can be made from 7.20 g of ethanoic ... (c) Anhydrous aluminium chloride contains 20.2% by mass of aluminium. (i) Show that the empirical formula for anhydrous aluminium chloride is A
Explanation:
