<span>The answer is CFCs. The abbreviation stands for Chlorofluorocarbons. They are made by fully
halogenating paraffin hydrocarbon. These compounds are known to cause climate change damaging the ozone layer. It is,
therefore, advisable to properly dispose off of refrigerators,
solvents and propellants</span>
Answer:
0.071 moles of Na₃PO₄ .
Explanation:
Given data:
Number of molecules of Na₃PO₄ = 4.3× 10²² molecules
Number of moles = ?
Solution:
1 mole contain 6.022 × 10²³ molecules
4.3× 10²² molecules × 1 mol / 6.022 × 10²³ molecules
0.71× 10⁻¹ mol
0.071 mol
The number 6.022 × 10²³ is called Avogadro number.
"It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance"
Answer:
The Third Law of thermodynamics states that the entropy of a pure substance in a perfect crystalline state at zero temperature is zero.
Explanation:
The generated Na+ and OH-ions are immediately surrounded by molecules of water (typically 6, each). There is the development of the exothermic hydration sphere for each ion. It seems as though there is negative overall energy of dissolving solid NaOH.
Now, since this dissolution is exothermic the temperature of the mixture rises.
Molarity= mol/ liters
since the molarity is given, we can assume that we have 1.0 Liters of solution
15.6 M= mol/ 1 liters---> this means that we have 15.6 moles of HNO3
we need to convert these moles to grams using the molar mass of HNO3
molar mass HNO3= 1.01 + 14.0 + (3 X 16.0)= 63.01 g/mol
15.6 mol HNO3 (63.01 g/ mol)= 983 grams HNO3
now we have to determine the grams of solution using the assumption of 1 liters of solution and the density
1 liters= 1000 mL
1000 mL (1.41 g/ ml)= 1410 grams solution
mass percent= mass of solute/ mass of solution x 100
mass percent= 63.01/ 1410 x 100= 4.47 %
