Answer:
+15.8°
Explanation:
The formula for the observed rotation (α) of an optically active sample is
α = [α]<em>lc
</em>
where
<em>l</em> = the cell path length in decimetres
<em>c</em> = the concentration in units of g/100 mL
[α] = the specific rotation in degrees
1. Convert the concentration to units of g/100 mL
2. Calculate the observed rotation
The earth is a vast, complex system powered by two sources of energy: an internal source (the decay of radioactive elements in the geosphere, which generates geothermal heat) and an external source (the solar radiation received from the Sun); the vast majority of the energy in the earth system comes from the Sun.
Answer is: <span> </span>ΔG for <span>methylamine is 18.85 kJ/mol.
</span>ΔG = R·T·lnK.
ΔG is Gibbs energy.
<span>T is the temperature on the Kelvin scale.
R is </span><span>ideal gas constant.
R = 8.314 J/mol</span>·K.
T = 25°C = 293.15 K.
Kb = 0.00044.
ΔG = - 8.314 J/mol·K · 293.15 K · ln(0.00044).
ΔG = 18836.85 J = 18.84 kJ.
Answer:
The 2 in the formula means that, there are 2 phosphate anions that forms the salt.
Explanation:
Magnesium phosphate is a ionic salt.
The formula indicates that 3 moles of Mg and 2 moles of anion phosphate are contained in 1 mol of compound.
3Mg²⁺ + 2PO₄⁻³ → Mg₃(PO₄)₂
The phosphate anion comes from phosphoric acid and it is generated when the acid loses the 3 protons.
H₃PO₄ → 3H⁺ + PO₄⁻³
Phosphate has a negative charge of -3, so when it bond to magnesium, which has a charge of +2, there must be 3 magnesium and 2 phosphate to make a global charge +6 -6 in the ions
