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.
Molar mass of CO2 = 44.01 g/mol
Answer:
Steam always has more thermal energy than ice.
Explanation:
Each mole of Ca(OH)₂ will produce 2 moles of OH- ions
Each mole of OH- ions will require one mole of H+ ions
Thus,
moles of OH- ions = moles of H+ ions = 2 x 0.3
moles of H+ ions required = 0.6
Each mole of HCl will produce one mole of H+ ions
Moles of HCl = moles of H+ ions
Moles of HCl = 0.6
