Explanation

• Among the given options, the process of tautomerism is exemplified by the first reaction: CH3COOH + C2H5OH ⇌ CH3COOC2H5 + H2O.
• Tautomerism involves the rearrangement of bonds within a molecule, resulting in the formation of structural isomers called tautomers, which readily interconvert.
• In this reaction, the acetic acid (CH3COOH) and ethanol (C2H5OH) undergo tautomerism to form ethyl acetate (CH3COOC2H5) and water (H2O).

Explanation

Elements having zero nuclear spin cannot be directly determined by NMR (Nuclear Magnetic Resonance) spectroscopy because NMR relies on the detection of signals from nuclei with non-zero nuclear spin.

Explanation

The metal that is most active is the one that can displace other metals from their salts. Based on the equations provided:

• Ni can displace Pb from Pb(NO3)2, so Ni is more active than Pb.
• Ni cannot displace Ag from AgNO3 (no reaction), so Ag is less active than Ni.
• Cu cannot displace Ag from AgNO3 (no reaction), so Ag is less active than Cu.

Therefore, the order of reactivity is: Ni > Pb > Cu > Ag

So, Ni is the most active metal among the options.

Explanation

The metal ions of transition metals are paramagnetic. The magnetic moment towards magnetic field is greatest of Fe^+3.

Explanation

In SF6 (sulfur hexafluoride), the central sulfur atom is bonded to six fluorine atoms in an octahedral arrangement. This results in two types of bond angles:

• The F-S-F bond angles in the equatorial plane are 90°
• The F-S-F bond angles between the equatorial and axial fluorine atoms are 180°

Explanation

• First, we calculate the number of moles of acetic acid used:

Number of moles of acetic acid = mass of acetic acid / molar mass of acetic acid

Number of moles of acetic acid = 30 g / 60 g/mol = 0.5 moles

Since the reaction is 1:1 between acetic acid and ethyl acetate, the number of moles of ethyl acetate produced is also 0.5 moles.

• Now, we can calculate the theoretical yield of ethyl acetate:

Theoretical yield of ethyl acetate = number of moles of ethyl acetate * molar mass of ethyl acetate

Theoretical yield of ethyl acetate = 0.5 moles * 88 g/mol = 44 grams

• Now, we can calculate the percentage yield:

Percentage yield = (actual yield / theoretical yield) * 100%

Percentage yield = (40 g / 44 g) * 100%

Percentage yield ≈ 90.9%

So, the percentage yield of the ester is approximately 90.9%.

Explanation

• The original sentence "Could you help me, please?" is in the active voice, where the subject ("you") performs the action ("help").
• When changing to the passive voice, the object ("me") becomes the subject, and the original subject ("you") becomes the agent of the action, but is often omitted in polite requests.
• Thus, the passive voice form is "Could I be helped, please?"

Explanation

We must try to understand his momentary aberration for Hyder has undergone more strain and anxiety than any among us.

Explanation

• The mass spectrum of CH3Br (methyl bromide) shows two peaks at m/z values of 94 and 96, corresponding to the molecular ions [CH3Br]+.
• These peaks are due to the natural abundance of bromine isotopes, 79Br and 81Br, which are present in a ratio of approximately 3:1.
• As a result, the peak at m/z 94 ([CH379Br]+) is about 3 times more intense than the peak at m/z 96 ([CH381Br]+).
  

Explanation

The oxidation of glucose to gluconic acid is a reaction that involves the loss of two electrons:

C6H12O6 (glucose) → C6H12O7 (gluconic acid)