Answer:
- The molar mass of the solute, in order to convert from moles of solute to grams of solute.
- The density of solution, to convert from volume of solution to mass of solution.
Explanation:
Hello,
In this case, since molarity is mathematically defined as the moles of solute divided by the volume of solution and the weight/weight percent as the mass of solute divided by the mass of solution, we need:
- The molar mass of the solute, in order to convert from moles of solute to grams of solute.
- The density of solution, to convert from volume of solution to mass of solution.
For instance, if a 1-M solution of HCl has a density of 1.125 g/mL, we can compute the w/w% as follows:
![w/w\%=1\frac{molHCl}{L\ sln}*\frac{36.45gHCl}{1molHCl}*\frac{1L\ sln}{1000mL\ sln}*\frac{1mL\ sln}{1.125g\ sln} *100\%\\\\w/w\%=3.15\%](https://tex.z-dn.net/?f=w%2Fw%5C%25%3D1%5Cfrac%7BmolHCl%7D%7BL%5C%20sln%7D%2A%5Cfrac%7B36.45gHCl%7D%7B1molHCl%7D%2A%5Cfrac%7B1L%5C%20sln%7D%7B1000mL%5C%20sln%7D%2A%5Cfrac%7B1mL%5C%20sln%7D%7B1.125g%5C%20sln%7D%20%20%20%20%2A100%5C%25%5C%5C%5C%5Cw%2Fw%5C%25%3D3.15%5C%25)
Whereas the first factor corresponds to the molar mass of HCl, the second one the conversion from L to mL of solution and the third one the density to express in terms of grams of solution.
Regards.
Oxygen and neon are both elements. Oxygen has 8 electrons and 8 protons. Neon has 10 electrons and 10 protons. Oxygen is also a non-metal element and Neon is a noble gas.
Answer:
131.5 kJ
Explanation:
Let's consider the following reaction.
CaCO₃(s) → CaO(s) + CO₂(g)
First, we will calculate the standard enthalpy of the reaction (ΔH°).
ΔH° = 1 mol × ΔH°f(CaO(s)) + 1 mol × ΔH°f(CO₂(g)
) - 1 mol × ΔH°f(CaCO₃(s)
)
ΔH° = 1 mol × (-634.9 kJ/mol) + 1 mol × (-393.5 kJ/mol) - 1 mol × (-1207.6 kJ/mol)
ΔH° = 179.2 kJ
Then, we calculate the standard entropy of the reaction (ΔS°).
ΔS° = 1 mol × S°(CaO(s)) + 1 mol × S°(CO₂(g)
) - 1 mol × S°(CaCO₃(s)
)
ΔS° = 1 mol × (38.1 J/mol.K) + 1 mol × (213.8 J/mol.K) - 1 mol × (91.7 J/mol.K)
ΔS° = 160.2 J/K = 0.1602 kJ/K
Finally, we calculate the standard Gibbs free energy of the reaction at T = 25°C = 298 K.
ΔG° = ΔH° - T × ΔS°
ΔG° = 179.2 kJ - 298 K × 0.1602 kJ/K
ΔG° = 131.5 kJ
Answer:
λ = 1*10⁻¹⁰m
Explanation:
Frequency (f) = 3.0*10¹²MHz = 3.0*10¹⁸Hz
Speed (v) = 3.0*10⁸m/s
Speed (v) of a wave = frequency (f) * wavelength (λ)
V = fλ
Solve for λ,
λ = v / f
λ = 3.0*10⁸ / 3.0*10¹⁸
λ = 1*10⁻¹⁰m
λ = 0.