Answer:
The heat that was used to melt the 15.0 grams of ice at 0°C is 4,950 Joules
Explanation:
The mass of ice in the beaker = 15.0 grams
The initial temperature of the ice = 0°C
The final temperature of the ice = 0°C
The latent heat of fusion of ice = 330 J/g
The heat required to melt a given mass of ice = The mass of the ice to be melted × The latent heat of fusion of ice
Therefore, the heat, Q, required to melt 15.0 g of ice = 15.0 g × 330 J/g = 4,950 J
The heat that was used to melt the 15.0 grams of ice = 4,950 Joules.
I believe the answer is a because 2 times 12 is 24. Hope this helped
<span>9.40x10^19 molecules.
The balanced equation for ammonia is:
N2 + 3H2 ==> 2NH3
So for every 3 moles of hydrogen gas, 2 moles of ammonia is produced. So let's calculate the molar mass of hydrogen and ammonia, starting with the respective atomic weights:
Atomic weight nitrogen = 14.0067
Atomic weight hydrogen = 1.00794
Molar mass H2 = 2 * 1.00794 = 2.01588 g/mol
Molar mass NH3 = 14.0067 + 3 * 1.00794 = 17.03052 g/mol
Moles H2 = 4.72 x 10^-4 g / 2.01588 g/mol = 2.34140921086573x10^-4 mol
Moles NH3 = 2.34140921086573x10^-4 mol * (2/3) = 1.56094x10^-4 mol
Now to convert from moles to molecules, just multiply by Avogadro's number:
1.56094x10^-4 * 6.0221409x10^23 = 9.400197448261x10^19
Rounding to 3 significant figures gives 9.40x10^19 molecules.</span>
<h2>Answer:</h2>
<em>8.67kJ/mol</em>
<h2>Explanations</h2>
The formula for calculating the amount of heat absorbed by the water is given as:

Determine the moles of KI

Since heat is lost, hence the enthalpy change of the solution will be negative that is:

Determine the enthalpy of solution in kJ•mol-1

Hence the enthalpy of solution in kJ•mol-1 for KI is 8.67kJ/mol
Na is the symbol for sodium.