Answer:
Explanation:
13 ) symbol of enthalpy change = Δ H .
14 ) enthalpy change is nothing but heat absorbed or evolved .
During fusion enthalpy change
Δ H .= m Lf , m is mass and Ls is latent heat of fusion
During evaporation, enthalpy change
Δ H .= m Lv , m is mass and Lv is latent heat of evaporation
during temperature rise , enthalpy change
Δ H = m c Δ T
In case of gas , enthalpy change can be calculated by the following relation
Δ H = Δ E + W , Δ E is change in internal energy , W is work done by gas.
15 ) When enthalpy change is negative , that means heat is released to the environment .So reaction is called exothermic .
when heat is absorbed enthalpy change is positive . Reaction is endothermic.
Atomic mass is the quantity of protons that have in a atom. Which atom have different numbers of protons, being able to be identified by them.
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The oceanographers define salinity by the number of grams of salt per kilogram of water.
Salinity is illustrated as how much salt is present in the given amount of water. It is dependent upon how much salt is found in the ocean in the specific regions. If there is a sunny environment, it may evaporate an ample amount of water, and leave behind a lot of salt, thus, the water has more salinity.
The salinity of the ocean is usually measured in Practical Salinity Unit (PSU), it is a unit based on the characteristics of seawater conductivity.
Answer:
C8H20P4F8
Explanation:
Molecular formula is based off a ratio of the molecular formula's molar mass divided by the empirical formula's molar mass.
The molar mass of the empirical formula C2H5PF2 is 98.02g. We find this by adding the molar masses of all elements in the formula, multiplied by their subscripts.
2(12.01) + 5(1.01) + 30.97 + 2(18.99) = 98.02
We then divide the molecular molar mass by the empirical molar mass.
392.16/98.02 = 4
This tells us that the molecular formula has 4 times the mass of the empirical formula. Because mass comes from the elements in the formula, we multiply all the subscripts by 4 to get the molecular formula.
2x4 = 8
5x4 = 20
1x4 = 4
2x4 = 8
So the molecular formula is C8H20P4F8
