If Gold's natural state has a definite shape and a definite volume, then its natural state is solid.
A. wavelength
wavelength is the distance between 2 crests of a wave
Answer:
0.75moles of H₄SiO₄
Explanation:
Given parameters:
Number of moles of H₂O = 1.5moles
Unknown:
Number of moles of H₄SiO₄ = ?
Solution:
To solve this problem, we need to write the reaction equation first;
SiO₂ + 2H₂O → H₄SiO₄
From the balanced reaction equation:
2 moles of water will produce 1 mole of H₄SiO₄
So 1.5 moles of water will produce 
= 0.75moles of H₄SiO₄
The purpose of using distilled water in the cuvette of the spectrophotometer is to calibrate the instrument. It is generally considered that distilled water shows zero absorbance and 100 % transmittance. So, to zero out the absorbance of compounds other than the analyte being determined, distilled water is used as a blank.
If the unknown being determined is prepared using ethanol as the base solution, the blank used must be ethanol. This is because absorbance if any from the solvent, ethanol must be zeroed out as when the measurement of the actual unknown is being made, the absorbance of the solvent does not interfere.
Answer:
Molar mass→ 0.930 g / 6.45×10⁻³ mol = 144.15 g/mol
Explanation:
Let's apply the formula for freezing point depression:
ΔT = Kf . m
ΔT = 74.2°C - 73.4°C → 0.8°C
Difference between the freezing T° of pure solvent and freezing T° of solution
Kf = Cryoscopic constant → 5.5°C/m
So, if we replace in the formula
ΔT = Kf . m → ΔT / Kf = m
0.8°C / 5.5 m/°C = m → 0.0516 mol/kg
These are the moles in 1 kg of solvent so let's find out the moles in our mass of solvent which is 0.125 kg
0.0516 mol/kg . 0.125 kg = 6.45×10⁻³ moles. Now we can determine the molar mass:
Molar mass (mol/kg) → 0.930 g / 6.45×10⁻³ mol = 144.15 g/mol
