<span>Radio waves are a type of electromagnetic radiation with wavelengths in the electromagnetic spectrum longer than infrared light. Radio waves have frequencies as high as 300 gigahertz (GHz) to as low as 30 hertz (Hz). ... Naturally occurring radio waves are emitted by lightning and astronomical objects.</span>
The enthalpy of formation of CF is -678.82 kJ/mol.
<h3>What is enthalpy ?</h3>
A thermodynamic system's enthalpy H is calculated by multiplying its internal energy by the product of its pressure and volume. In the equation H = U + pV, U stands for internal energy, p for pressure, and V for system volume; pV is also frequently referred to as the pressure energy P.
The amount of heat in a system under constant pressure is measured as enthalpy (H). Chemists frequently gauge how the enthalpy of chemical systems changes when reactants transform into products. The enthalpy change, which is the same thing as the heat that is absorbed or released by a process at constant pressure, is denoted by the letter H.
To learn more about enthalpy from the given link:
brainly.com/question/3393755
#SPJ4
Answer:
Molarity = 8.89 mol/L
Explanation:
Given data:
Mass of hydrogen peroxide = 3%
Density = 1.01 g/mol
Molarity = ?
Solution:
3% hydrogen peroxide means 3 g of H₂O₂ are present in 100 g of solution.
Now we will calculate the moles of H₂O₂.
Number of moles = mass / molar mass
Number of moles = 3g/ 34 g/mol
Number of moles = 0.88 mol
Now we calculate the volume of solution.
d = m/v
v = m/ d
v= 100 g/ 1.01 g/ mL
v = 99 mL
In Litter
v = 99 / 1000 = 0.099 L
Molarity:
Molarity = number of moles / volume in L
Molarity = 0.88 mol/ 0.099 L
Molarity = 8.89 mol/L
Answer:
1. Density can be used to identify a substance
2. Density can be used to ascertain whether a substance will float in water.
Explanation:
The calculation of the density of a substance can be used to identify the substance. If the density of a substance is calculated accurately, and compared with a table of standard densities, then we can identify that substance.
Also, density determines whether an object will float or sink in water. If an object is less dense than water then it will float in water. If it is denser than water, then it will sink in water.
Answer:
27.6 %.
Explanation:
- Acetone has the molecular formula (C₃H₆O).
- The molar mass of acetone is the summation of the atomic mass of the elements forming it multiplied by its number of atoms.
Atomic mass of C = 12.011 g/mol.
Atomic mass of H = 1.008 g/mol.
Atomic mass of O = 15.999 g/mol.
- The molar mass of acetone = [(3 x atomic mass of C) + (6 x atomic mass of H) + (Atomic mass of O)] = [(3 x 12.011 g/mol) + (6x 1.008 g/mol) + (15.999 g/mol)] = 58.08 g/mol.
- The mass % of any element = [(no, of the element atoms x atomic mass of the element) / molar mass of the compound] x 100.
∴ The mass % of O = (Atomic mass of O / molar mass of acetone) x 100 = [(15.999 g/mol) / (58.08 g/mol)] = 27.6 %.