20600Cal
Explanation:
Given parameters:
Mass of water = 319.5g
Initial temperature = 35.7°C
Final temperature = 100°C
Unknown:
Calories needed to heat the water = ?
Solution:
The calories is the amount of heat added to the water. This can be determined using;
H = m c Ф
c = specific heat capacity of water = 4.186J/g°C
H is the amount of heat
Ф is the change in temperature
H = m c (Ф₂ - Ф₁)
H = 319.5 x 4.186 x (100 - 35.7) = 85996.56J
Now;
1kilocalorie = 4184J
85996.56J to kCal; 
= 20.6kCal = 20600Cal
learn more:
Specific heat brainly.com/question/3032746
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This means a release of free energy from the system corresponds to a negative change in free energy, but to a positive change for the surroundings.
A chemical change is characterized of the formation of new substances or a chemical reaction. There are a number of observations that we can see if this type of change happens. One would be the formation of gas bubbles, this indicates that one of the products is a gas. Another observation would be a formation of a precipitate in the solution, it would indicate that the new solid formed is not soluble in the solution. A permanent color change in the solution would also indicate a chemical change because it may be that the new substance that is formed has its own distinct color when in solution.
A base and an Acid always react to form a salt and water
So, HCl + NaOH —> NaCl + HOH
The compound with a chemical formula of C₃H₈ is propane. The subscripts actually represent the number of the individual atoms in 1 particle of the compound. Since there are the same number of atoms per mole of any substance, the subscript can also represent the moles. Through stoichiometric calculations, the solution is as follows:
Moles of Carbon = 11.2 moles H * 3 mol C/8 mol H = <em>4.2 moles</em>
