Answer: By performing the flame test
Explanation:
The flame test can be performed by the teacher to visually identify the substance in the solution. The metals give a characteristic color on burning. The heat of the flame causes the excitation of the electrons present in the metal ions this leads to release of energy along with the emission of visible wavelength of light. This visible light can be observed by human eye. For example, the copper produces the blue color in flame, barium gives green flame, and sodium gives yellow flame.
The correct letter to your answer would be A
Each Be–Cl bond is polar because the two atoms have different electronegativities. The number of outer atoms (2) and lone pairs on the central atom (0) indicate that this molecule has a linear geometry. The bonds in a linear molecule are symmetric, and so their dipoles cancel out.
Each O–H bond is polar because the two atoms have different electronegativities. The number of outer atoms (2) and lone pairs on the central atom (2) indicate that this molecule has a bent geometry. The bonds in a bent molecule are asymmetric, and so their dipoles do not cancel out. In addition, the asymmetric arrangement of the lone pairs on O further contribute to the dipole of this molecule.
An O–O or O=O bond is nonpolar because the two atoms have the same electronegativity. Because there is no overall polarity in O2, the molecule is nonpolar.
Every mole of MgCl2 reacts with 2 moles of KOH, therefore the 4 moles of KOH will only react with 2 moles of MgCl2, making it the limiting reagent and therefore KOH determines how much Mg(OH)2 is produced.